food and beverages - · pdf filefood and beverages ... titration (or titrimetric analysis) is...

Food

and

Bev

erag

es

31

Selected Titration Applications

Food & Beverages Industry

General

and

KF Titrators

EDITORIAL Dear Reader

Food and Beverages (F&B) Industry is subject to regulations covering the whole production process for the benefit of food safety, consumer protections and (inter)national trade. Requirements are stipulated for composition, microbiological status, residues, contaminants and other properties.

For this reason, well-defined analytical reference methods are needed at all stages of the production chain. Among other techniques, content determination by titration is a widely used analytical technique, in particular for routine analysis of raw materials as well as final products. Titration (or titrimetric analysis) is a quantitative analytical method which nowadays comes with a large extent of automation from sample preparation to addition of reagents, result calculations and data storage.

METTLER TOLEDO solutions such as titrators, sample changers and various sensors fulfil almost any requirement of titrimetric analysis. In particular, One Click™ operation, robust and qualified instruments as well as a variety of systems and accessories to suit your needs and budget allow the use of titrators at all F&B production sites, testing and research labs. In addition, qualified training can be achieved with our EDUPacs professional education packages, i.e. educational scripts describing the detailed procedures that are used for the operator training. EDUPacs enable standardized execution and documentation of operator training on the instruments.

Valuable support is provided to you by our large collection of titration methods which are field-tested and approved by a long history of practice, so you know your methods are suited for the best results possible on your instrument. Here METTLER TOLEDO offers you a collection of segment-specific Titration Applications Brochures.

We, at the Market Support Group Analytical Chemistry are proud to present to you our Application Brochure 31 on titration the Food and Beverages Industry. It shall serve you as a valuable source of information and hope that it will support you in your daily laboratory tasks.

Dr. Hans-Joachim Muhr Dr. Cosimo A. De Caro Market Support Manager Senior Applications Chemist BA Titration BA Titration

METTLER TOLEDO

METTLER TOLEDO - I - Titration in Food & Beverages

Contents

Method Title Acid/Base Titration (aqueous)

M400 Acetic Acid Content in Vinegar

M402 Free Fatty Acids (FFA) Content in Edible Oils

M403 Blank Value of Free Fatty Acids (FFA) Solvent

M487 Determination of Fat Acidity in Corn Flour According to AOAC 939.05 Method

M494 pH and Acidity in Wine by Automated Aliquoting

Chloride Content

M379 Acid and Chloride Content in Wine

M404 Chloride Content in Ketchup

M486 Low Content Chloride Determination

Vitamin C

M411 Vitamin C Content in Orange Juice: Voltametric Indication

M412 Vitamin C Content in Orange Juice: Amperometric Indication Sulphur Dioxide (SO2)

M419 Free Sulphur Dioxide (SO2) Content in Wine

M564 Total Sulphur Dioxide (SO2) Content in Wine

Characteristic Values

M051 Iodine Value according to Wijs (AOAC method 993.20, 2012): Sample and Back Value

M618 Saponification Value of Edible Oils and Fats

M369 Peroxide Value of Edible Oils and Fats (AOAC method 28.022)

METTLER TOLEDO

METTLER TOLEDO - II - Titration in Food & Beverages

Method Title Kjeldahl Nitrogen Content

M454 Kjeldahl Nitrogen – Connection with TTL/IO output

Various Applications

M269 Calcium Content in Dairy Products by Back-Titration using a Cu-ISE

M443 Calibration of a Potassium Ion Selective Electrode – DX239-K+ ISE

M444 Potassium Content Determination in Water by Direct Measurement

M472 Citrate Content Determination Using a Cu-Ion Selective Electrode

M476A Determination of Nitrite Content in Soya Sauce: Back Titration with FAS

M485 Determination of Potassium Sorbate (E 202) in Food Products

M488 Determination of Milk Fat Content According to CAC/RM 15-1969

M489 Determination of Chondroitin Sulfate According to USP

Water Content (Karl Fischer Titration)

M304 Water Determination in Milk Powder (Homogenizer)

M306 Water Determination in Corn Starch with Drying Oven DO308

M394 KF Coulometry: Surface Water in Brown Sugar by External Extraction

M490 Water Content in Oils by KF Coulometry at High Temperature (40-50°C)

M623 Water Content in Edible Oils and Fats

METTLER TOLEDO

METTLER TOLEDO - III - Titration in Food & Beverages

Titration in the F&B Industry F&B samples for titration are various and very different: for this reason, each sample

needs a specific preparation previous titration analyses, and the suitable sensor has to be selected. The following table illustrates selected examples of titrimetric analysis in the F&B:

Analysis Sample Component Titration Sensor

Salt content

‐ Ketchup ‐ Dairy products ‐ Vegetable juices ‐ Snack food ‐ Spices, Sauces

Salt as chloride content

Precipitation titration with silver nitrate

Combined silver ring electrode

Acid content

‐ Vinegar ‐ Fruit juices ‐ Vegetable juices ‐ Wine ‐ Soft drinks ‐ Milk ‐ Honey ‐ Edible oils and fats

Acidic components

Neutralization titration with alkaline titrant

Combined pH glass electrode

Calcium content

‐ Milk ‐ Soil milk ‐ Cheese ‐ Yoghurts ‐ Juices ‐ Cream

Calcium ions Complexometric titration with EDTA

Photometric sensor DP5 Phototrode™ (color indicator) or Ca-ISE, Cu-ISE

Vitamin C content

‐ Fruit juices ‐ Vegetable juices ‐ Dried fruit

Vitamin C Redox titration

Combined platinum ring redox electrode or polarized double pin electrode

Free and Total SO2

‐ Wine ‐ Cider ‐ Fruit based drinks ‐ Flour ‐ Dried fruit

Sulfur dioxide, SO2

Redox titration with iodine

Combined platinum ring redox electrode or polarized double pin electrode

Kjeldahl Nitrogen

‐ Milk ‐ Cheese ‐ Yoghurt ‐ Butter ‐ Meat ‐ Vegetables

Ammonium ion, NH4

+ Neutralization titration with acidic titrant


Iodine value ‐ Butter ‐ Margarine ‐ Edible oils and fats

Acidic components

Redox titration with sodium thiosulphate

Combined platinum ring redox electrode

Saponification Value

‐ Butter ‐ Margarine ‐ Edible oils and fats

Alkaline components

Neutralization titration with acidic titrant


Reducing sugar according to Rebelein

‐ Wine ‐ Juices

Reducing sugars

Redox titration with sodium thiosulphate

Combined platinum ring redox electrode

Water content by Karl Fischer titration

‐ Sugar ‐ Flour ‐ Butter, cheese ‐ Coffee, chocolate ‐ Chocolate

Water Redox titration with iodine

Polarized double pin electrode

METTLER TOLEDO

METTLER TOLEDO - IV - Titration in Food & Beverages

References A selection of relevant literature references will allow you to get more information on

titration in food and beverage samples.

[1] AOAC International - Association of Official Analytical Chemists, www.aoac.org

[2] IDF - International Dairy Federation, www.fil-idf.org

[3] ISO - International Organization for Standardization, www.iso.org

[4] FAO – Food and Agriculture Organization www.fao.org

[5] EFSA – European Food Safety Authority www.efsa.europa.eu

[6] Swiss Food Manual (Schweizerisches Lebensmittelbuch, SLMB) www.slmb.bag.admin.ch

[7] German Food Manual (Deutsches Lebensmittelbuch) www.bmelv.de/EN/

[8] FDA – US Food and Drug Administration, www.fda.gov

[9] FSA - Food Standard Agency, UK www.food.gov.uk

http://www.aoac.org/

http://www.fil-idf.org/

http://www.iso.org/

http://www.fao.org/

http://www.efsa.europa.eu/

http://www.slmb.bag.admin.ch/

http://www.bmelv.de/EN/

http://www.fda.gov/

http://www.food.gov.uk/

METTLER TOLEDO Page 1 of 6 Titration Application M400-2009

METTLER TOLEDO Application M400-2009

Acetic Acid Content in Vinegar The acetic acid content is determined in vinegar by titration with sodium hydroxide.

Preparation and Procedures Note:

This method allows a fully automated analysis procedure. The method can be easily modified for manual operation. Select "Manual stand" in the method function "Titration stand".

1) Adjustment of the DG115-SC pH glass electrode: The electrode is adjusted using pH buffers 4.01, 7.00, and 9.21 before starting the analysis.

2) The titer of sodium hydroxide is determined using potassium hydrogen phthalate as a primary standard (KHP): 80 mg is dissolved into 50 mL deionized water and titrated.

3) Approximately 1 g vinegar is added to 50 mL deionized water into a titration beaker.

4) In the T50/T70/T90 application, the sample series was analyZed using a Rondolino sample changer in combination with a diaphragm pump.

The rinsing time was defined to 2 s. In this way, the electrode is cleaned with deionized water before starting the subsequent sample.

Remarks

1) The method parameters have been developed and optimized for the above mentioned sample.

2) Since there are different kinds of vinegar, it

may be necessary to slightly adapt the method to your specific sample.

Sample Vinegar, 0.7-1 g.

Compound Acetic acid, CH3COOH, M = 60.05 g/mol, z = 1

Chemicals 50 mL deionized water

Titrant Sodium hydroxide, NaOH c(NaOH) = 0.1 mol/L

Standard Potassium hydrogen phthalate, KHP, 80 mg

Indication DG115-SC

Chemistry CH3COOH + NaOH → CH3COONa + H2O

Calculation Content (%), expressed as w/w: R1 = Q*C/m, C = M/(10*z)

Waste disposal

Neutralization before final disposal as aqueous solution.

Author, Version

Thomas Hitz, MSG, July 2006 Ralph Egli, MSG, May 2009


Instruments - T50/T70/T90 Titration Excellence, G20 Compact Titrator (with small changes). - XS205 Balance - Rondolino Sample Changer with diaphragm pump and PowerShower™

Accessories - 1 x 10 mL DV1010 burette - Titration beaker ME-101974 - Olivetti Printer JobJet 210

Results T50/T70/T90 All results Method-ID M400 Sample Vinegar (1/1) R1 (Content) 4.713 % Sample Vinegar (1/2) R1 (Content) 4.734 % Sample Vinegar (1/3) R1 (Content) 4.718 % Sample Vinegar (1/4) R1 (Content) 4.717 % Sample Vinegar (1/5) R1 (Content) 4.722 % Sample Vinegar (1/6) R1 (Content) 4.724 % Statistics Method-ID M400 R1 Content Samples 6 Mean 4.738 % s 0.007 % srel 0.152 %

Titration curve T50/T70/T90


Table of measured values T50/T70/T90

Comments T50/T70/T90

--


Results G20 All results Method-ID M400 Sample Vinegar (1/6) R1 (Content) 4.781 % Sample Vinegar (2/6) R1 (Content) 4.763 % Sample Vinegar (3/6) R1 (Content) 4.776 % Sample Vinegar (4/6) R1 (Content) 4.779 % Sample Vinegar (5/6) R1 (Content) 4.780 % Sample Vinegar (6/6) R1 (Content) 4.774 % Statistics Method-ID M400 R1 Content Samples 6 Mean 4.776 % s 0.007 % srel 0.139 %

Titration curve G20

Not available

Table of measured values G20 Not available

Comments G20 1. For the G20 Compact Titrator results, no automation was used. Each sample has been added

manually to the titration stand.


Method T50/T70/T90 001 Title Type General titration Compatible with T50 / T70 / T90 ID M400 Title Acetic acid content in vinegar Author METTLER TOLEDO Date/Time 02.08.2006 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 Vinegar Entry type Weight Lower limit 0.7 g Upper limit 1.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Rondolino TTL) Type Rondolino TTL Titration stand Rondolino TTL 1 004 Stir Speed 35% Duration 10 s Condition No 005 Titration (EQP) [1] Titrant Titrant NaOH Concentration 0.1 mol/L Sensor Type pH Sensor DG115-SC Unit pH Temperature acquisition Temperature acquisition No Stir Speed 35% Predispense Mode Volume Volume 1 ml Wait time 5 s Control Control User Titrant addition Dynamic dE (set value) 12 mV dV (min) 0.005 mL dV (max) 0.5 mL Meas. val. acquisition Equilibrium controlled dE 0.5 mV dt 1 s t (min) 3 s t (max) 30 s Evaluation and recognition Procedure Standard Threshold 5 pH/mL Tendency Positive Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 006 Calculation R1 Result Content Result unit % Formula R1=Q*C/m Constant C M/(10*z) M M[Acetic acid] z z[Acetic acid] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No

007 Record Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V Last titration function log dE/dV - V No d2E/dV2 - V No BETA – V No E - t No V - t No dV/dt - t No T – t No E – V & dE/dV – V No V – t & dV/dt – t No Method No Series data No Condition No 008 End of sample


Method G20 Compact Titrator 001 Title Type General titration Compatible with G20 ID M400 Title Acetic Acid in Vinegar Author Administrator Date/Time 02.08.2009 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 Vinegar Entry type Weight Lower limit [g] 0.7 Upper limit [g] 1.0 Density [g/mL] 1.0 Correction factor 1.0 Temperature [°C] 25.0 Entry Arbitrary 003 Titration stand (Rondolino TTL) Type Rondolino TTL Titration stand Rondolino TTL 1 004 Stir Speed [%] 35 Duration [s] 10 005 Titration (EQP) [1] Titrant Titrant NaOH Concentration [mol/L] 0.1 Sensor Type pH Sensor DG115-SC Unit pH Temperature acquisition Temperature acquisition No Stir Speed [%] 35 Predispense Mode Volume Volume [mL] 1.0 Wait time [s] 5 Control Control User Titrant addition Dynamic dE (set value) [mV] 12.0 dV (min) [mL] 0.005 dV (max) [mL] 0.5 Mode Equilibrium controlled dE [mV] 0.5 dt [s] 1 t (min) [s] 3 t (max) [s] 30 Evaluation and recognition Procedure Standard Threshold [pH/mL] 5 Tendency Positive Ranges 0 Add. EQP criteria No Termination At Vmax [mL] 20.0 At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 006 Calculation R1 Result type Predefined Calculation type Direct titration Result Content Result unit % Formula R1=Q*C/m Selected EQP 1 Constant C=M/(10*z) M M[Acetic acid] z z[Acetic acid] Decimal places 3 Result limits No Record statistics Yes

007 Record Summary No Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V Last titration function log dE/dV - V No d2E/dV2 - V No BETA – V No E - t No V - t No dV/dt - t No T – t No E – V & dE/dV – V No V – t & dV/dt – t No Method No Series data No Condition No 008 End of sample



Free Fatty Acids Content in Edible Oil Determination of the free fatty acids (FFA) content in edible oil by potentiometric titration with ethanolic potassium hydroxide in a non-aqueous mixture consisting of ethanol and diethylether (1:1 v/v).

Preparation and Procedures Note: This method allows for an automated procedure using a sample changer and an additional dosing unit. The method can be easily modified for manual operation. Select "Manual stand" in the method function "Titration stand".

1) The titer is determined using benzoic acid: 25 mg is added into a glass titration beaker, and dissolved with 60 mL solvent mixture. Since the amount is rather small, a balance with a resolution of at least 0.1 mg is needed.

CAUTION: Benzoic acid is an aggressive substance. Avoid contact with skin and eyes, particularly

2) A blank value is determined for every new batch of solvent mixture (see M403) and stored as B[Solvent FFA].

3) Approx. 2-4 g of olive oil is weighed into a titration beaker.

4) 60 mL solvent mixture are added by an additional dosing unit (20 mL burette) in two steps to improve sample dissolution. It can be performed manually with a pipette.

5) After each titration the DG113-SC sensor was rinsed with solvent by means of the diaphragm pump of the Rondolino sample changer (Rondolino Settings: Pos. "1").

Remarks

1) The method parameters have been developed and optimized for the above mentioned sample. Thus, it may be necessary to slightly adapt the method to your specific sample.

2) To ensure hydration of the DG113 glass membrane, the electrode is stored over night in water. Before titration, wash the electrode with solvent mixture.

3) Some samples can give rather flat titration curve, and noise can appear. To increase the potential jump, 1 mL 0.05 mol/L benzoic acid is added to 1 L of solvent mixture. This is also of help if the blank determination is not possible due to very low titrant consumption.

Sample Olive oil, 2-4 g

Compound Free fatty acids as mg KOH/g sample, M=56.1 g/mol, z=1

Chemicals 60 mL ethanol:diethylether 1:1 (v/v)

Titrant Potassium hydroxide in ethanol, KOH c(KOH) = 0.02 mol/L

Standard Potassium hydrogen phthalate, 25 mg

Indication DG113-SC

Chemistry R-COOH + KOH → R-COO- + K+ + H2O R-COOH: Free fatty acids

Calculation Acid number (mg KOH/g) R1=(Q-B[FFA])*C/m, C=M, z=1 FFA in olive oil (g FFA/100g) R2=(Q-B[FFA])*C/m, C=M*0.1, z=1 M[Oleic acid] = 282.47 g/mol

Waste disposal

Neutralization before final disposal as organic solvent.

Author, Version

Melanie Nijman, MSG Anachem, July 2006



Accessories - 10 mL DV1010 and 20 mL DV1020 glass burettes - 1 additional Dosing Unit - Glass titration beaker ME-101446 - Olivetti Printer JobJet 210

Results All results Method-ID M402 Sample Edible oil (1/1) R1 (Content) 0.846807 mg KOH/g R2 (Content) 0.426301 g/100g Sample Edible oil (1/2) R1 (Content) 0.845652 mg KOH/g R2 (Content) 0.425720 g/100g Sample Edible oil (1/3) R1 (Content) 0.847853 mg KOH/g R2 (Content) 0.426828 g/100g Sample Edible oil (1/4) R1 (Content) 0.847045 mg KOH/g R2 (Content) 0.426421 g/100g Sample Edible oil (1/5) R1 (Content) 0.847805 mg KOH/g R2 (Content) 0.426804 g/100g Sample Edible oil (1/6) R1 (Content) 0.842935 mg KOH/g R2 (Content) 0.424352 g/100g Statistics Method-ID M402 R1 Content Samples 6 Mean 0.846350 mg KOH/g s 0.001856 mg KOH/g srel 0.219 % R2 Oleic acid content Samples 6 Mean 0.426071 g/100g s 0.000934 g/100g srel 0.219 %

Titration curve


Table of measured values

Comments

• The acid number is a measure of the decomposition by lipase enzyme in edible oil and fats. The decomposition is speeded up by heat and light. Rancidity is due to decomposition and it is accompanied by free fatty acid formation.

• The free fatty acid content (FFA) is defined as the amount in g of oleic acid (C18H34O2) in 100 g sample. Depending on the type of oil, it is also indicated as the amount of lauric or palmitic acid.

• Literature: “Edible Oil and Fat”, METTLER TOLEDO Titration Applications Brochure No. 24, ME-51 725 054.


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID M402 Title Free fatty acid content Author METTLER TOLEDO Date/Time 02.08.2006 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 Edible oil Entry type Weight Lower limit 0.0 g Upper limit 5.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Rondolino TTL) Type Rondolino TTL Titration stand Rondolino TTL 1 004 Dispense (normal)[1] Titrant Solvent FFA Concentration 1 Volume 20.0 mL Dosing rate 60.0 mL/min Condition No 005 Stir Speed 35% Duration 10 s Condition No 006 Dispense (normal)[2] Titrant Solvent FFA Concentration 1 Volume 40.0 mL Dosing rate 60.0 mL/min Condition No 007 Stir Speed 35% Duration 10 s Condition No 008 Titration (EQP) [1] Titrant Titrant KOH in EtOH Concentration 0.02 mol/L Sensor Type pH Sensor DG113-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 35% Predispense Mode Volume Volume 1.0 mL Wait time 0 s Control Control User Titrant addition Dynamic dE (set value) 12.0 mV dV (min) 0.01 mL dV (max) 0.3 mL Meas. Val. acquisition Equilibrium controlled dE 1.0 mV dt 2 s t(min) 2 s t(max) 15 s Evaluation and recognition Procedure Standard Threshold 20 mV/mL Tendency Negative Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No

After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 009 Calculation R1 Result Content Result unit mg KOH/g Formula R1=(Q-B[Solvent FFA]*C/m Constant C=M/z M M[Potassium hydroxide] z z[Potassium hydroxide] Decimal places 6 Result limits No Record statistics No Extra statistical func. No Send to buffer No Condition No 010 Calculation R2 Result Oleic acid content Result unit g/100g Formula R2=(Q-B[Solvent FFA])*C/m Constant C=M/(10*z) M M[Oleic acid] Z z[Oleic acid] Decimal places 6 Result limits No Add. statistics functionalities No 011 Record Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V Last titration function ... 012 End of sample ------------------------------------------------------------- G20 Compact Titrator Method: The G20 method includes slightly modifications: ... 004 Dispense (normal)[1] Titrant Solvent FFA Concentration 1 Volume 60.0 mL Dosing rate 60.0 mL/min Condition No (The G20 has only one

dispense function available) ... 009 Calculation R1 Result type Predefined Calculation type Blank comp. Formula R1=(Q-B[Blank])*C/m Selected EQP 1 Result Content Result unit mg/g Constant C M/z M M[Potassium hydroxide] z z[Potassium hydroxide] Decimal places 4 Result limits No Record statistics Yes 010 Calculation R2 Result type Predefined Calculation type Blank comp. Formula R1=(Q-B[Blank])*C/m Selected EQP 1 Result Content Result unit g/100g Constant C M/(10*z) M M[Oleic acid] z z[Oleic acid] Decimal places 4 Result limits No Record statistics Yes



Blank Value of Free Fatty Acids (FFA) Solvent Determination of the blank value for free fatty acids (FFA) content in edible oil by potentiometric titration with ethanolic potassium hydroxide in a non-aqueous mixture consisting of ethanol and diethylether (1:1 v/v).

Preparation and Procedures Note: This method allows for an automated procedure using a sample changer and an additional dosing unit. The method can be easily modified for manual operation. Select "Manual stand" in the method function "Titration stand".

1) The titer is determined using benzoic acid: 25 mg is added into a glass titration beaker, and dissolved with 60 mL solvent mixture. Since the amount is rather small, a balance with a resolution of at least 0.1 mg is needed.

CAUTION: Benzoic acid is an aggressive substance. Avoid contact with skin and eyes, particularly.

2) A blank value is determined for every new batch of solvent mixture and stored as B[Solvent FFA].

3) 60 mL solvent mixture are added by an additional dosing unit (20 mL burette). It can be performed manually with a pipette.

4) After each titration the DG113-SC sensor was rinsed with solvent by means of the diaphragm pump of the Rondolino sample changer (Rondolino Settings: Pos. "1").

Remarks

1) The method parameters have been developed and optimized for the above mentioned sample. Thus, it may be necessary to slightly adapt the method to your specific sample.

2) To ensure hydration of the DG113 glass

membrane, the electrode is stored over night in water. Before titration, wash the electrode with solvent mixture.

3) If needed, the solvent is spiked with 1 mL 0.05 mol/L

added to 1 L of solvent mixture. In this way, the potential jump is more pronounced.

Sample 60 mL ethanol:diethylether 1:1 (v/v)

Compound Acid components, z=1

Chemicals --

Titrant Potassium hydroxide in ethanol, KOH c(KOH) = 0.02 mol/L

Standard Potassium hydrogen phthalate, 25 mg

Indication DG113-SC

Chemistry R-COOH + KOH → R-COO- + K+ + H2O R-COOH: Free fatty acids

Calculation Blank value R1=Q, mmol

Waste disposal

Neutralization before final disposal as organic solvent.

Author, Version

Melanie Nijman, MSG Anachem, July 2006



Accessories - 10 mL DV1010 and 20 mL DV1020 glass burettes - 1 additional Dosing Unit - Glass titration beaker ME-101446 - Olivetti Printer JobJet 210

Results All results Method-ID M403 Sample Solvent FFA (1/1) R1 (Content) 0.002486 mmol Sample Solvent FFA (1/2) R1 (Content) 0.002612 mmol Sample Solvent FFA (1/3) R1 (Content) 0.002697 mmol Sample Solvent FFA (1/4) R1 (Content) 0.002573 mmol Sample Solvent FFA (1/5) R1 (Content) 0.002638 mmol Sample Solvent FFA (1/6) R1 (Content) 0.002543 mmol Sample Solvent FFA (1/6) R1 (Content) 0.002543 mmol Statistics Method-ID M403 R1 Consumption Samples 7 Mean 0.002592 mmol s 0.000068 mmol srel 2.615 %

Titration curve



Comments

• The acid number is a measure of the decomposition by lipase enzyme in edible oil and fats. The decomposition is speeded up by heat and light. Rancidity is due to decomposition and it is accompanied by free fatty acid formation.

• The free fatty acid content (FFA) is defined as the amount in g of oleic acid (C18H34O2) in 100 g sample. Depending on the type of oil, it is also indicated as the amount of lauric or palmitic acid.

• Literature: “Edible Oil and Fat”, METTLER TOLEDO Titration Applications Brochure No. 24, ME-51 725 054.


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID M403 Title Blank solvent FFA Author METTLER TOLEDO Date/Time 02.08.2006 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 Solvent FFA Entry type Fixed volume Volume 60 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Rondolino TTL) Type Rondolino TTL Titration stand Rondolino TTL 1 004 Dispense (normal)[1] Titrant Solvent FFA Concentration 1 Volume 60.0 mL Dosing rate 60.0 mL/min Condition No 005 Stir Speed 35% Duration 60 s Condition No 006 Titration (EQP) [1] Titrant Titrant KOH in EtOH Concentration 0.02 mol/L Sensor Type pH Sensor DG113-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 35% Predispense Mode None Wait time 0 s Control Control User Titrant addition Dynamic dE (set value) 8.0 mV dV (min) 0.005 mL dV (max) 0.03 mL Meas. Val. acquisition Equilibrium controlled dE 1.0 mV dt 1 s t(min) 3 s t(max) 30 s Evaluation and recognition Procedure Standard Threshold 20 mV/mL Tendency Negative Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 007 Calculation R1 Result Consumption Result unit mmol Formula R1=Q Constant C=1 M M[None] z z[None] Decimal places 6 Result limits No

Record statistics Yes Extra statistical func. No Send to buffer No Condition No 008 Record Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V Last titration function ... 009 End of sample 010 Blank Name Solvent FFA Value B=Mean[R1] Units mmol Limits No 011 Calculation R2 Result Blank solvent FFA Result unit mmol Formula R2=Mean[R1] Constant C=1 M M[None] z z[None] Decimal places 6 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 012 Record Results Yes Raw results No Resource data No Calibration curve No Method No Series data No ------------------------------------------------------------- G20 Compact Titrator Method: The G20 method includes slightly modifications: ... 007 Calculation R1 Result type Predefined Calculation type Direct titration Formula R1=Q Selected EQP 1 Result Consumption Result unit mmol Constant C 1 M M[None] z z[None] Decimal places 6 Result limits No Record statistics Yes ... 011 Calculation R2 Result type Predefined Formula R2=Mean[R1] Result Mean Result unit -- Constant C 1 Decimal places 5 Result limits No Record statistics Yes


METTLER TOLEDO Application M487-2011 Determination of Fat Acidity in Corn Flour According to AOAC 939.05 Method

Determination of the acidity in corn flour by titration with potassium hydroxide after extraction according to the Association of Official Analytical Chemists AOAC 939.05 (2010) Official Method of Analysis.

Preparation and Procedures Precautions: - Use safety goggles and wear gloves while

handling acids, use a mask or work in a fume hood.

Electrode: - Ensure the cleaning of electrode is sufficient after

each titration by using deionized water. - The electrode should be dipped in pH 7 buffer

solution for hydration after every titration.

Blank preparation: - Mix 25mL of each benzene and ethanol is titrated

with 0.0178 mol/L of KOH.

Preparation of corn flour: - Grind 200 g of corn so that 90% will pass through

No. 40 sieve.

Sample preparation: - Weigh 20 gm ± 0.01 of sample and add 50 mL

benzene. - Shake it for 45 minutes - Let the meal settle, then filter and collect the

filtrate in 25 mL flask. - Mix equal volume of ethanol with the 25 mL of

extracted sample solution in a titration beaker - Titrate it with 0.0178 mol/L of KOH. Remarks

- Clean the burette tip, electrode and stirrer thoroughly with ethanol.

- Depending on the sample lot, sample solution gets turbid sometimes at the time of titration.

- In this case, add more 25 mL of benzene in the extracted sample solution before titration and 50 mL of ethanol, and then titrate it with KOH.

- Similarly, determine the blank value also with increased volume of solvent.

- After each sample, the electrode is conditioned in water to completely remove any residue.

- Before starting the next sample, electrode and stirrer were dabbed dry with a soft tissue.

- This application does not replace the official AOAC method.

Sample Acidic components in corn flour

Compound R-COOH, expressed as free fatty acids

Chemicals Benzene, C6H6 Ethanol, C2H5OH

Titrant Potassium hydroxide, KOH c(KOH) = 0.0178 mol/L

Standard Potassium hydrogen phthalate, KHP

Indication DGi116-Solvent non aqueous combined pH glass electrode

Chemistry R-COOH + KOH → R-COOK + H2O

Calculation Fat acidity (AOAC 939.05):

R1 = 10*(VEQ-B[Blank])

R1 indicates the fat acidity in mg/100 g, where 1 mL 0.0178 M = 1 mg KOH. This is the amount of mg KOH needed to neutralize 100 g of corn sample (dry sample). Blank:

R1 = VEQ

Waste disposal

Aromatic organic waste.

Author, Version

Sohel R. Ansari, IMSG AnaChem, Nov 2011; Rev.: C. De Caro, MSG AnaChem, Nov. 2011


Instruments - Titration Excellence T50/T70/T90, Compact Titrator G20 - XP 205 Balance

Accessories - LabX pro titration - 1 x 10mL DV1010 glass burette - 100 mL Titration Beaker

Results

All results Method-ID Fat acidity Content Fat acidity (1/3) R1 (mg/100g) 35.76879 Content Fat acidity (2/3) R1 (mg/100g) 35.63201 Content Fat acidity (3/3) R1 (mg/100g) 36.31263 Statistics Method-ID Acidity R1 3 Samples 3 Mean 35.90448 mg/100g S 0.36003 mg/100g Srel 1.003 %

Titration curve

Sample 1/3 Fat Acidity 10/24/2011 4:47:46 PM Start time: 11/2/2011 2:19:21 PM



Volume Increment Signal Change 1st deriv. Time Temperature

mL mL mV mV mV/mL s °C

0.0000 NaN 183.2 NaN NaN 0 25.0 0.0100 0.0100 173.8 -9.4 NaN 8 25.0 0.0200 0.0100 157.2 -16.6 NaN 24 25.0 0.0300 0.0100 145.3 -11.9 NaN 34 25.0 0.0440 0.0140 130.0 -15.3 NaN 46 25.0 0.0560 0.0120 119.3 -10.7 -809.55 57 25.0 0.0725 0.0165 109.0 -10.3 -683.88 65 25.0 . . . . . . . . . . . . . . . . . . . . . 3.4215 0.1000 -100.4 -9.4 -92.71 223 25.0 3.5215 0.1000 -110.6 -10.2 -101.20 230 25.0 3.6215 0.1000 -120.7 -10.1 -116.34 237 25.0 3.7215 0.1000 -131.8 -11.1 -138.62 246 25.0 3.8215 0.1000 -147.7 -15.9 -160.41 258 25.0 3.8785 0.0570 -158.0 -10.3 -176.35 267 25.0 EQP1 3.927569 NaN -168.9 NaN -184.23 NaN NaN 3.9375 0.0590 -1711.0 -13.1 -184.22 279 25.0 3.9810 0.0435 -178.2 -7.1 -178.26 286 25.0 4.0810 0.1000 -196.2 -18.0 -156.88 300 25.0 4.1415 0.0605 -204.8 -8.6 -137.08 308 25.0 4.2415 0.1000 -216.9 -12.1 -111.62 316 25.0 3.9375 0.0590 -1711.0 -13.1 -184.22 279 25.0 . . . . . . . . . . . . . . . . . . . . .

Sample 1/3 Fat Acidity 10/24/2011 4:47:46 PM Start time: 11/2/2011 2:19:21 PM

Comments

General remarks:

• Mean value of three replicates of blank is stored as auxiliary value and used for calculation in sample.

• Blank values in the order of approx. 0.35 mL have been determined.

• The titrant has to be protected against the intake of CO2 from the air by CO2-absorbing material. Inm fact, CO2 is rapidly absorbed by alkaline solution, leading to the formation of carbonate in the solution. As a consequence, the titer of the solution is strongly affected.

• To reduce the analysis time, larger max. increments and a predispensing step can be defined.

Literature:

• Association of Official Analytical Chemists (AOAC) Official Method 939.05, “Fat Acidity – Grains”, Method II – Rapid Method for Corn, AOAC Official Methods of Analysis, Chap. 32 “Cereal Foods”, 2010, page 42 (www.aoac.org).

• See also: JAOAC 23, 493 (1940); JAOAC 24, 587 (1940).

http://www.aoac.org/


Method Sample titration 001 Title Type General titration Compatible with T50 / T70 / T90 ID FatAcidity Title FatAcidity Author admin Date/Time 10/18/2011 3:59:36 PM Modified at 10/24/2011 4:47:46 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 0.0 g Upper limit 25.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30 % Duration 30 s Condition No 005 Titration (EQP) [1] Titrant Titrant KOH Concentration 0.0178 mol/L Sensor Type pH Sensor DG116-Solvent Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30 % Predispense Mode None Wait time 0 s Control Control User Titrant addition Dynamic dE (set value) 12.0 mV dV (min) 0.01 mL dV (max) 0.1 mL Mode Equilibrium controlled dE 0.5 mV dt 1.0 s t (min) 3.0 s t (max) 30.0 s Evaluation and recognition Procedure Standard Threshold 100 mV/mL Tendency None Ranges 0 Add. EQP criteria Steepest jump Steepest jumps 1 Termination At Vmax 15.0 mL At potential No At slope No After number of recognized EQPs No Combined termination criteria No Accompanying stating Accompaning stating No Condition Condition No 006 Calculation R1 Result Content Result unit mg/100g Formula R1=10*(VEQ-B[Blank]) Constant C=1 M M[None] z z[None] Decimal places 5 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 007 End of sample

Blank determination 001 Title Type General titration Compatible with T50 / T70 / T90 ID Blank Title Blank Author admin Date/Time 10/18/2011 10:38:38 AM Modified at 11/2/2011 10:56:07 AM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Fixed volume Volume 25.0 mL . . . . . 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30 % Duration 30 s Condition No 005 Titration (EQP) [1] Titrant Titrant KOH Concentration 0.0178 mol/L Sensor Type pH Sensor DG116-Solvent Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30 % Predispense Mode None Wait time 0 s Control Control User Titrant addition Dynamic dE (set value) 12.0 mV dV (min) 0.01 mL dV (max) 0.1 mL Mode Equilibrium controlled dE 0.5 mV dt 1.0 s t (min) 3.0 s t (max) 30.0 s Evaluation and recognition Procedure Standard Threshold 20 mV/mL Tendency None Ranges 0 Add. EQP criteria Steepest jump Steepest jumps 1 Termination At Vmax 2.0 mL At potential No At slope No After number of recognized EQPs No Combined termination criteria No Accompanying stating Accompaning stating No Condition Condition No 006 Calculation R1 Result Consumption Result unit mL Formula R1=VEQ Constant C=1 . . . . . 007 End of sample 008 Calculation R2 Result Mean blank Result unit mL Formula R2=Mean[R1] . . . . . 009 Blank Name Blank Value B= R2 Unit mL Limits No Condition No

METTLER TOLEDO Page 1 of 6 Titration Application M494

METTLER TOLEDO Application M494

pH and Acidity in Wine by Automated Aliquoting

The pH value and the acidity in wine are determined with a combined pH glass electrode and by acid/base

titration to pH value 8.2. The sample size is automatically adjusted by draining using a diaphragm pump.

Preparation and Procedures

CAUTION

‐ Use safety goggles, a lab coat and wear gloves.

‐ Ensure accurate cleaning of sensor is sufficient

after each titration.

Titer determination:

‐ Weigh 70-120 mg KHP into a titration beaker

‐ Add 50 mL deionized water

‐ Start titer determination

Electrode adjustment:

‐ Use buffers pH 4.01, 7.00 and 9.21.

Determination of sample volume

‐ Fill the titration beaker with an excess sample

volume e.g. ~20 mL of 0.1 M hydrochloric acid.

‐ Adjust the volume with siphoning by the diaph-

ragm pump, add water, titrate with 0.1 M NaOH.

‐ The consumption indicates the sample volume.

It is stored as auxiliary value H[Wine Level]

Sample titration:

‐ Fill the titration beaker up to approx. 60 mL (see

graduated scale on beaker wall).

‐ The method is started and first the sample is

degassed using nitrogen gas and slow stirring to

avoid interference of CO2 on the measurements.

‐ Subsequently, the pH value is measured.

‐ The sample size for titration is achieved by

siphoning excess wine using a diaphragm pump.

‐ The accurate volume has been previously

determined by titration of know sample volume.

‐ The sample is diluted by adding deion. water by

means of a peristaltic pump.

Remarks

‐ The application method has been developed for

the mentioned sample. It may be necessary to

optimize the method for your sample.

‐ A sample changer may be used in this method

for a fully automatic procedure. The method can

easily be modified for operation with a sample

changer by defining it correspondingly.

‐ Literature: See applications M561 and M435

Sample Californian red wine,

approx. 60 mL

(5-10 mL for titration)

Compound Tartaric acid, C4H6O6

HO2CCH(OH)CH(OH)CO2H

M = 150.09 g/mol, z = 2

Chemicals Deionized water

pH 4.01, 7.00 and 9.21 buffers

0.1 M Hydrochloric acid

Nitrogen gas

Titrant Sodium hydroxide, NaOH

c(NaOH) =0.1 mol/L

Standard Potassium hydrogenphthalate,

KHP, 0.070 - 0.120 g

Indication DGi115-SC

combined pH glass electrode

Chemistry C4H6O6 + 2 NaOH

Na2C4H4O6 + 2 H2O

Calculation Method 1:

Sample volume calibration

R = VEQ, in mL

C = 1

Stored as auxiliary value

H[Wine Level]

Method 2:

pH value:

R1 = E, in pH

C = 1

Total acidity (as tartaric acid):

R2 = Q*C/H[Wine level]

C = M/(10*z)

Waste

disposal

Neutralize the titrated solutions

before final disposal

Author,

Version

Matt Eby, Marketing AnaChem,

Version 1.0


Instruments ‐ Titration Excellence T50/T70/T90

(Other titrators: depending on instrument type, manual operation and method

changes are necessary)

‐ 1 x 10 mL DV1010 glass burette

‐ 1 x Stop valve for carrier gas (ME-51108615)

‐ 1 x Drying unit for carrier gas (ME-51108660) with tube set (ME-51108666)

Accessories ‐ XS205 Balance

‐ 1 x SP250 peristaltic pump with tubes and adapters

‐ 1 x Diaphragm pump with tubes and adapters

‐ PP Titration beakers

‐ Spatula

Results (calibration of sample volume)

All results

Method-ID m494A

Sample 5-10 mL 0.1 M HCl (1/3)

R1 (Consumption) 7.3284 mL





Statistics

Method-ID m494A

R1 Consumption

Samples 3

Mean 7.2291 mL

s 0.009935 mL

srel 1.374 %

Titration curve (calibration of sample volume)

Sample 1/5


Table of measured values (calibration of sample volume)



0 NaN 306.4 NaN NaN 0 25

1.7145 1.7145 285.9 -20.5 NaN 22 25

2.5715 0.857 279.8 -6.1 NaN 28 25

3 0.4285 276.5 -3.3 NaN 31 25

3.5 0.5 270.9 -5.6 NaN 45 25

4 0.5 266.4 -4.5 -10.42 48 25

4.5 0.5 261 -5.4 -12.32 52 25

5 0.5 254.3 -6.7 -14.99 55 25

5.5 0.5 246 -8.3 -22.54 58 25

6 0.5 234.3 -11.7 -39.55 63 25

6.3665 0.3665 220.3 -14 -67.45 68 25

6.5255 0.159 210.7 -9.6 -95.68 72 25

6.631 0.1055 201.7 -9 -131.88 76 25

6.7135 0.0825 192.1 -9.6 -187.98 80 25

6.7775 0.064 181.1 -11 -303.53 85 25

6.816 0.0385 170.9 -10.2 -524.77 90 25

6.841 0.025 161.2 -9.7 -769.32 94 25

6.8585 0.0175 151.8 -9.4 -921.74 98 25

6.8735 0.015 140.9 -10.9 -1111.68 102 25

6.8885 0.015 120.8 -20.1 -1387.35 115 25

6.9035 0.015 83.5 -37.3 -1851.42 145 25

6.9185 0.015 56.3 -27.2 -2569.38 172 25

6.9335 0.015 35 -21.3 -3166.39 182 25

6.9485 0.015 -12.4 -47.4 -2962.48 213 25

EQP1 6.949485 NaN -17.9 NaN -3216.37 NaN NaN

6.9635 0.015 -96.8 -84.4 -2264.41 243 25

6.9785 0.015 -140.9 -44.1 -1836.59 267 25

6.9935 0.015 -154.1 -13.2 -1650.09 277 25

7.031 0.0375 -173.8 -19.7 NaN 285 25

7.063 0.032 -184.2 -10.4 NaN 290 25

7.1135 0.0505 -195.6 -11.4 NaN 293 25

7.176 0.0625 -205.7 -10.1 NaN 297 25

7.2635 0.0875 -215.5 -9.8 NaN 300 25

0 NaN 306.4 NaN NaN 0 25

Comments

The acidity is determined by an endpoint titration to pH 8.2 for historical reason. In fact, pH 8.2 is the

value where the color indicator phenolphthalein is changing.

The suction tube of the diaphragm pump is positioned in the titration beaker at approximately the

height of the desired sample volume e.g. 5-10 mL. A calibration titration with 0.1 M HCl allows for

determination of the sample volume after draining of excess sample.

CO2 dissolved in wine affects the results. For this reason, the sample is degassed by means of a

nitrogen gas stream during 45 s before pH measurement and acidity titration.

The outlet of a nitrogen gas bottle is connected to the stop valve for carrier gas ME-51108615 which

is in turn mounted to the drying unit ME-51108660.

The gas flow is activated by the stop valve (24 V). The valve is controlled by a method function

PUMP (Auxiliary reagent: Nitrogen, Pump: Solenoid, Rate: 60 mL/min):

Precision of the wine analysis may be lower than for other samples. Degassing time has an impact

on the results and should be defined by the end user based off product and nitrogen flow rate.


Results (pH and acidity determination)

All results

Method-ID m494B

Sample Calif. Cabernet Sauvignon (1/5)

R1 (Potential) 3.726 pH

R2 (Total Acidity) 0.575 g/100 mL













Statistics

Method-ID m494B

R2 Total acidity

Samples 5

Mean 0.570 g/100 mL

s 0.011696 g/100 mL

srel 2.053 %

Titration curve (pH and acidity determination)

Sample 1/5

Table of measured values (pH and acidity determination)

Volume Increment Signal Change Time Temperature mL mL mV mV s °C

0 NaN 3.685 NaN 0 25

0.002 0.002 3.668 -0.017 1 25

0.0065 0.0045 3.67 0.002 2 25

. . . . . . . . . . . . . . . . . .

5.422 0.006 8.089 0.02 57 25

5.4255 0.0035 8.102 0.013 58 25

5.429 0.0035 8.112 0.01 59 25

5.4335 0.0045 8.12 0.008 60 25

5.439 0.0055 8.124 0.004 61 25

5.4455 0.0065 8.143 0.019 62 25

5.446 0.0005 8.153 0.01 63 25

5.449 0.003 8.152 -0.001 64 25

5.4535 0.0045 8.166 0.014 65 25

5.4545 0.001 8.173 0.007 66 25

5.4575 0.003 8.174 0.001 67 25

5.462 0.0045 8.181 0.007 68 25

5.4625 0.0005 8.189 0.008 69 25

5.463 0.0005 8.191 0.002 70 25

5.466 0.003 8.194 0.003 71 25

5.467 0.001 8.198 0.004 72 25

5.468 0.001 8.201 0.003 73 25

5.468 0 8.202 0.001 74 25


Methods

Sample volume calibration

001 Title

Type General titration

Compatible with T50 / T70 / T90

ID m494A

Title Sample volume calibration

. . .

002 Sample

Number of IDs 1

ID 1 5-10 mL 0.1 M HCl

Entry type Volume

Lower limit 5 mL

Upper limit 10 mL

Density 1.0 g/mL

Correction factor 1.0

Temperature 25.0°C

Entry Arbitrary

003 Titration stand (Manual stand)

Type Manual stand

Titration stand Manual stand 1

004 Drain

Drain pump Wine drain

Drain volume 80 mL

Condition No

005 Pump

Auxiliary reagent Water

Volume 50 mL

Condition No

006 Stir

Speed 35%

Duration 5 s

Condition No

007 Titration (EQP) [1]

Titrant

Titrant NaOH

Concentration 0.1 mol/L

Sensor

Type pH

Sensor DG115-SC

Unit mV

Temperature acquisition

Temperature acquisition No

Stir

Speed 30%

Predispense

Mode Volume

Volume 3 mL

Wait time 10 s

Control

Control User

Titrant addition Dynamic

dE(set value) 10 mV

dV(min) 0.015 mL

dV(max) 0.5 mL

Mode Equilibrium controlled

dE 0.5 mV

dt 2 s

t(min) 3 s

t(max) 30 s

Evaluation and recognition

Procedure Standard

Threshold 200.0 mV/mL

Tendency Negative

Ranges 0

Add.EQP criteria No

Termination

At Vmax 10.0 mL

At potential No

At slope No

After number of

Recognized EQPs Yes

Number of EQPs 1

Combined termination

criteria No

Accompanying stating

Accompanying stating No

Condition

Condition No

008 Calculation R1

Result Consumption

Result unit mL

Formula R1=VEQ

Constant C=1

M M[None]

z z[None]

Decimal places 4

Result limits No

Record statistics Yes

Extra statistical func. No

Send to buffer No

Condition No

009 End of sample

010 Auxiliary value

Name Wine Level

Formula H= Mean[R1]

Limits No

Condition No


pH and total acidity

001 Title

Type General titration

Compatible with T50 / T70 / T90

ID m494B

Title Degas wine - pH and acidity

. . .

002 Sample

Number of IDs 1

ID 1 Wine

Entry type Volume

Lower limit 5 mL

Upper limit 10 mL

Density 1.0 g/mL

Correction factor 1.0

Temperature 25.0°C

Entry Arbitrary

003 Titration stand (Manual stand)

Type Manual stand

Titration stand Manual stand 1

004 Stir

Speed 20%

Duration 1 s

Condition No

005 Pump

Auxiliary reagent Nitrogen

Volume 45 mL

Condition No

006 Measure (normal) [1]

Sensor

Type pH

Sensor DG115-SC

Unit pH


Temperature Measurement No

Stir

Speed 35%

Acquisition of measured values

Acquisition Equilibrium controlled

dE 0.5 mV

dt 3 s

t(min) 5 s

t(max) 45 s

Mean No

Condition

Condition No

007 Stir

Speed 0%

Duration 0 s

Condition No

008 Drain

Drain pump Wine drain

Drain volume 80 mL

Condition No

009 Pump

Auxiliary reagent Water

Volume 50 mL

Condition No

010 Titration (EP) [1]

Titrant

Titrant NaOH

Concentration 0.1 mol/L

Sensor

Type pH

Sensor DG115-SC

Unit pH


Temperature acquisition No

Stir

Speed 30%

Predispense

Mode None

Wait time 0 s

Control

Mode Absolute

Tendency Positive

End point value 8.2 pH

Control band 1.5 pH

Dosing rate (max) 20 mL/min

Dosing rate (min) 200 µL/min

Termination

At EP Yes

Termination delay 1

At Vmax 20 mL

Max.time ∞

Accompanying stating

Accompanying stating No

Condition

Condition No

011 Calculation R1

Result Potential

Result unit pH

Formula R1=E

Constant C=1

M M[None]

z z[None]

Decimal places 3

Result limits No

Record statistics No


Send to buffer No

Condition No

012 Calculation R2

Result Total Acidity

Result unit g/100 mL

Formula R2=Q*C/H[Wine Level]

Constant C=M/(10*z)

M M[Tartaric acid]

z z[Tartaric acid]

Decimal places 3

Result limits No

Record statistics Yes


Send to buffer No

Condition No

013 End of sample



Acid and Chloride Content in Wine

Method for the determination of tartaric acid and chloride in wine. The analysis is monitored with a pH glass combined electrode as well as a combined silver ring electrode.

Preparation and Procedures CAUTION ‐ Use safety goggles, a lab coat and wear gloves.

If possible, work in a fume hood. ‐ Ensure accurate cleaning of electrode is

sufficient after each titration. Before the acid content analysis is performed the pH electrode needs to be adjusted by use of the METTLER TOLEDO buffers 4.01, 7.00 and 9.21 and method M436.

Remarks

‐ When working with Rondo30 and two mini electrodes lower sample volumes can be used for two consecutive titrations in the same sample.

‐ In this method conditioning in the conditioning beaker is used for electrode cleaning, alternatively, rinsing with the Rondo30 power shower can be used.

‐ When automation with Rondo30 is not required, microtitration beakers can also be used when wanting to use smaller sample volumes.

Sample Wine, 40 mL

Compound Tartaric acid, (CHOH)2(COOH)2 M(CHOH)2(COOH))=150.09, z = 2 Chloride, Cl- M(Cl-) = 35.45, z = 1

Chemicals 2 mL 10% sulfuric acid, H2SO4

Buffers pH 4.01, 7.00 and 9.21

Titrant Sodium hydroxide, NaOH c(NaOH) = 1.0 mol/L Silver nitrate, AgNO3 c( AgNO3) = 0.02 mol/L

Standard NaCl for AgNO3, KHP for NaOH

Indication DGi102-Mini (pH sensor) DMi102-SC (silver electrode)

Chemistry EP titration: C4H6O6 + 2 NaOH → Na2C4H4O6 + 2 H2O EQP titration: Cl- + Ag+ + NO3

- → AgCl + NO3

-

Calculation R1: Consumption NaOH (mL)

R2: Measurement pH (pH) (before chloride determ.)

R3: Chloride content (mg/L)

Waste disposal

AgCl has to be disposed of as special waste.

Author, Version

Melanie Nijman, MSG AnaChem, October 2007


Instruments ‐ Titration Excellence T70/T90 ‐ 2 additional dosing units ‐ 2 x 10 mL DV1010 glass burettes ‐ XS205 Balance

Accessories ‐ LabX® titration software ‐ Rondo 30 sample changer (51108004) with 80 m sample beakers (51108030)

Results Method m379 Acid and Chloride Content in Wine Measured 11.10.2007 RESULTS No. ID Sample size and results 1 Wine 40.0 ml R1 = 3.0744 ml Content R2 = 1.660 pH pH value R3 = 33.6713 mg/L Chloride content 2 Wine 40.0 ml R1 = 3.0925 ml Content R2 = 1.662 pH pH value R3 = 33.7785 mg/L Chloride content 3 Wine 40.0 ml R1 = 3.1120 ml Content R2 = 1.670 pH pH value R3 = 33.8016 mg/L Chloride content 4 Wine 40.0 ml R1 = 3.0839 ml Content R2 = 1.669 pH pH value R3 = 33.7493 mg/L Chloride content 5 Wine 40.0 ml R1 = 3.0739 ml Content R2 = 1.669 pH pH value R3 = 33.7564 mg/L Chloride content 6 Wine 40.0 ml R1 = 3.0859 ml Content R2 = 1.671 pH pH value R3 = 33.8069 mg/L Chloride content STATISTICS Number results R1 n = 6 Mean value x = 3.0871 ml Consumption Standard deviation s = 0.0141 ml Consumption Relative standard deviation srel = 0.4570 % Number results R2 n = 6 Mean value x = 1.667 pH pH value Standard deviation s = 0.005 pH pH value Relative standard deviation srel = 0.277 % Number results R3 n = 6 Mean value x = 33.7607 mg/L Chloride content Standard deviation s = 0.0495 mg/L Chloride content Relative standard deviation srel = 0.1470 %

Titration curve

Sample 4/6: EP titration (Acidity) and Chloride determination with EQP titration



Volume Increment Signal 1st deriv. Time

mL mL mV mV/mL s

0 NaN -8.7 NaN 0

0.114 0.114 -8.1 NaN 7

0.171 0.057 -8.2 NaN 18

0.2 0.029 -8.3 NaN 28

0.272 0.072 -8 NaN 44

0.454 0.182 -5.9 10.75 54

0.654 0.2 -3.1 12.89 64

0.854 0.2 0 15.51 74

1.054 0.2 4.2 20.56 84

1.254 0.2 8.6 30.61 94

1.454 0.2 15 49.33 104

1.626 0.172 24 81.38 114

1.698 0.072 29.6 104.22 124

1.748 0.05 35.2 123.05 135

1.787 0.039 40.4 137.53 145

1.823 0.036 46.1 154.77 155

1.856 0.033 52 174.95 165

1.886 0.03 57.5 182.53 175

EQP1 1.904043 NaN 60.8 183.31 NaN

1.918 0.032 63.3 181.94 185

1.95 0.032 69.1 174.58 196

1.984 0.034 74.9 163.2 206

2.021 0.037 80.9 148.88 216

2.062 0.041 86.7 132.92 226

2.107 0.045 92.4 NaN 236

2.163 0.056 98.4 NaN 246

2.228 0.065 104.2 NaN 256

2.309 0.081 110.1 NaN 266

2.408 0.099 116 NaN 276

0 NaN -8.7 NaN 0

0.114 0.114 -8.1 NaN 7

0.171 0.057 -8.2 NaN 18

0.2 0.029 -8.3 NaN 28

Comments --


Method 001 Title Type General titration Compatible with T70 / T90 ID m379 Title Acid and Chloride Content in

Wine Author Mettler-Toledo Date/Time 10.10.2007 hh:mm:ss Modified at 10.10.2007 hh:mm:ss Modified by Administrator Protect No SOP None 002 Sample Number of IDs 1 ID 1 Wine Entry type Fixed volume Volume 40.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Rondo60/Tower A) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 10 s Condition No 005 Titration (EP) [1] Titrant Titrant NaOH Concentration 1.0 mol/L Sensor Type pH Sensor DG102-Mini Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Mode Absolute Tendency None End point value 7.0 Control band 0.2 Dosing rate(max)[mL/min] 20 mL Dosing rate(max)[µL/min] 300 µL/min Termination At EP Yes Termination delay 0 s At Vmax 5 mL Max. time 20000 s Accompanying stating Accompanying stating No Condition Condition No 006 Dispense (normal) [1] Titrant H2SO4 10% Concentration 1 mol/L Volume 2.0 mL Dosing rate 60.0 mL/min Condition No 007 Measure (normal) Sensor Type pH Sensor DG102-Mini Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Acquisition of measured values Acquisition Equilibrium controlled dE 0.5 mV dt 1 s t(min) 10 s t(max) 30 s Mean value No Condition

Condition No 008 Titration (EQP) [2] Titrant Titrant AgNO3

Concentration 0.02 mol/L Sensor Type mV Sensor DM102-SC Unit SC Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode Volume Volume 0.2 mL Wait time 5 s Control Control User Titrant addition Dynamic dE (set value) 6 mV dV (min) 0.02 mL dV (max) 0.2 mL Mode Equilibrium controlled dE 1.0 mV dt 2 s t (min) 10 s t (max) 30 s Evaluation and recognition Procedure Standard Threshold 150 mV/mL Tendency None Ranges 0 Add. EQP criteria No Termination At Vmax 6.0 At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No 009 Calculation R1 Result Consumption Result unit mL Formula R1=VEQ[1] Constant C=2 M M[None] z z[None] Decimal places 5 . . . . 010 Calculation R2 Result pH value Result unit pH Formula R2=E[1] Constant C=1 M M[None] z z[None] Decimal places 3 . . . . 011 Calculation R3 Result Chloride content Result unit mg/L Formula R3=Q[2]*C/m Constant C=M*1000/z M M[Chloride] z z[Chloride] Decimal places 5 . . . . 012 Conditioning Type Fix Interval 1 Position Conditioning beaker Time 20 s Speed 35% Condition No 013 Record . . . . 014 End of sample



Chloride Content in Ketchup The chloride content in ketchup is determined by precipitation titration with silver nitrate. The content is given as sodium chloride, NaCl (salt).


1) The titer determination of silver nitrate is performed using sodium chloride (NaCl) as a primary standard. Since small amounts of salt cannot be weighed in exactly, it is recommended to prepare an aqueous solution of NaCl, and then to add the standard with a pipette.

2) Approximately 1.5 g ketchup is added in a titration beaker. Ketchup is dissolved by adding 50 mL 0.02 mol/L H2SO4.

3) After each sample the DM141-SC electrode, the stirrer and the titration dispensing tube are cleaned using a paper tissue soaked with deionized water to completely remove any AgCl residue.

Remarks

1) The method parameters have been developed and optimized for the above mentioned sample.

2) Since there are different ketchup producers, it may be necessary to slightly adapt the method to your specific sample.

3) The method can be easily modified for automated operation. Select the appropriate sample changer in the method function "Titration stand".

Sample Ketchup, 1.4-1.6 g

Compound Sodium chloride, NaCl, M = 58.44 g/mol, z = 1

Chemicals 50 mL sulphuric acid, H2SO4 c(H2SO4) = 0.02 mol/L

Titrant Silver nitrate, AgNO3 c(AgNO3) = 0.1 mol/L

Standard Natrium chloride, NaCl c(NaCl) = 0.1 mol/L , 5 mL

Indication DM141-SC

Chemistry NaCl + AgNO3 → AgCl + NaNO3

Calculation R1: Content (%), expressed as w/w R1 = Q*C/m, C = M/(10*z)

Waste disposal

Filtration. The precipitate (AgCl) has to be classified as special waste. The liquid phase has to be neutralized to pH 7 before final disposal.

Author, Version

Claudia Schreiner, April 2009, Thomas Hitz, July 2006, Market Support Group Anachem


Instruments - T50/T70/T90 Titration Excellence, G20 Compact Titrator (with small changes). - XS205 Balance

Accessories - DV1010 burette - Titration beaker ME-101974 - Olivetti Printer JobJet 210

Results T50/T70/T90 All results Method-ID M404 Sample Ketchup (1/1) R1 (Content) 3.287 % Sample Ketchup (1/2) R1 (Content) 3.274 % Sample Ketchup (1/3) R1 (Content) 3.287 % Sample Ketchup (1/4) R1 (Content) 3.290 % Sample Ketchup (1/5) R1 (Content) 3.273 % Sample Ketchup (1/6) R1 (Content) 3.284 % Statistics Method-ID M404 R1 Content Samples 6 Mean 3.282 % s 0.007 % srel 0.220 %

Titration curve T50/T70/T90


Table of measured values T50/T70/T90

Comments T50/T70/T90

--


Results G20 All results Method-ID M404 Sample Ketchup (1/9) R1 (Content) 3.205 % Sample Ketchup (2/9) R1 (Content) 3.201 % Sample Ketchup (3/9) R1 (Content) 3.206 % Sample Ketchup (4/9) R1 (Content) 3.212 % Sample Ketchup (5/9) R1 (Content) 3.216 % Sample Ketchup (6/9) R1 (Content) 3.219 % Sample Ketchup (7/9) R1 (Content) 3.213 % Sample Ketchup (8/9) R1 (Content) 3.211 % Sample Ketchup (9/9) R1 (Content) 3.215 % Statistics Method-ID M404 R1 Content

Titration curve G20

Table of measured values G20 Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C 0.000 NaN 47.3 NaN NaN 0 25.0 2.286 2.286 58.2 10.9 NaN 6 25.0 3.429 1.143 65.8 7.6 NaN 10 25.0 6.818 0.009 203.4 7.9 798.37 72 25.0 6.828 0.010 212.2 8.8 889.32 75 25.0 6.828767 NaN 213.0 NaN 889.32 NaN 25.0 6.836 0.008 220.7 8.5 862.92 78 25.0 6.845 0.009 228.0 7.3 765.78 81 25.0 6.857 0.012 238.0 10.0 673.16 84 25.0 6.868 0.011 245.0 7.0 603.17 87 25.0 6.887 0.019 254.1 9.1 NaN 90 25.0 6.912 0.025 263.1 9.0 NaN 94 25.0 6.944 0.032 271.8 8.7 NaN 97 25.0 6.990 0.046 280.7 8.9 NaN 100 25.0 7.054 0.064 289.9 9.2 NaN 103 25.0


Method T50/T70/T90 001 Title Type General titration Compatible with T50 / T70 / T90 ID M404 Title Chloride content in ketchup Author METTLER TOLEDO Date/Time 02.08.2006 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 Ketchup Entry type Weight Lower limit 1.4 g Upper limit 1.6 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 35% Duration 15 s Condition No 005 Titration (EQP) [1] Titrant Titrant AgNO3

Concentration 0.1 mol/L Sensor Type mV Sensor DM141-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 35% Predispense Mode Volume Volume 1 ml Wait time 5 s Control Control User Titrant addition Dynamic dE (set value) 9 mV dV (min) 0.008 mL dV (max) 0.4 mL Meas. Val. acquisition Equilibrium controlled dE 0.5 mV dt 1 s t(min) 3 s t(max) 30 s Evaluation and recognition Procedure Standard Threshold 250 mV/mL Tendency Positive Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 006 Calculation R1 Result Content Result unit % Formula R1=Q*C/m Constant C=M/(10*z) M M[Sodium chloride] z z[Sodium chloride] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No

007 Record Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V Last titration function log dE/dV - V No d2E/dV2 - V No BETA – V No E - t No V - t No dV/dt - t No T – t No E – V & dE/dV – V No V – t & dV/dt – t No Method No Series data No Condition No 008 End of sample


Method G20 Compact Titrator 001 Title Type General titration Compatible with G20 ID M404 Title Chloride content in ketchup Author Administrator Date/Time 02.08.2009 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 Ketchup Entry type Weight Lower limit [g] 0.9 Upper limit [g] 1.6 Density [g/mL] 1.0 Correction factor 1.0 Temperature [°C] 25.0 Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed [%] 35 Duration [s] 15 005 Titration (EQP) [1] Titrant Titrant AgNO3 Concentration [mol/L] 0.1 Sensor Type mV Sensor DM140-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed [%] 35 Predispense Mode Volume Volume [mL] 4.0 Wait time [s] 10 Control Control User Titrant addition Dynamic dE (set value) [mV] 9.0 dV (min) [mL] 0.008 dV (max) [mL] 0.4 Mode Equilibrium controlled dE [mV] 0.5 dt [s] 1 t (min) [s] 3 t (max) [s] 30 Evaluation and recognition Procedure Standard Threshold [pH/mL] 250 Tendency Positive Ranges 0 Add. EQP criteria No Termination At Vmax [mL] 10.0 At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 006 Calculation R1 Result type Predefined Calculation type Direct titration Result Content Result unit % Formula R1=Q*C/m Selected EQP 1 Constant C=M/(10*z) M M[Sodium chloride] z z[Sodium chloride] Decimal places 3 Result limits No Record statistics Yes

007 Record Summary No Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V Last titration function log dE/dV - V No d2E/dV2 - V No BETA – V No E - t No V - t No dV/dt - t No T – t No E – V & dE/dV – V No V – t & dV/dt – t No Method No Series data No Condition No 008 End of sample



Low Level Chloride Content Determination This method represents a general purpose chloride (salt) titration with parameters set to ensure a high degree of precision down to 0.5 ppm standard by precipitation titration with potentiometric and voltametric titration.


- Preparation of 0.01 mol/L AgNO3: Weigh 1.699 g AgNO3 into a 1000 mL volumetric flask, dissolved it in a small amount of deionized water and make up the volume with deionized water. Protect this solution from light by storing it in an amber colored bottle.



For sample preparation: Refer the preparation under “Results”

Remarks

- A 5% non-ionic surfactant solution (e.g. Triton X-100) can be added to avoid formation of larger precipitate and does not stick to the electrode as well.

- After each sample, the electrode is conditioned in deionized water to completely remove any residue.

- Before starting the next sample, electrode and stirrer were dabbed dry with a soft tissue.

Sample NaCl aqueous solution, equivalent to corresponding Cl at ppm level.

Compound Chloride, Cl M = 35.453 g/moL z = 1

Chemicals 0.02 M Sulphuric acid, H2SO4 5% Non-ionic surfactant -(TritonX-100) 100% Acetic acid Acetone GR

Titrant Silver nitrate, AgNO3 c(AgNO3) = 0.01 mol/L , 0.0025 mol/L , 0.0001 mol/L

Standard Sodium chloride solution

Indication DM141-SC (Potentiomety) DM143-SC (Voltametry)

Chemistry NaCl + AgNO3 → AgCl + NaNO3

Calculation Content:

R = Q*C/(m*d) C = M*1000/z for ppm, or C = M/(10*z) for % Q = Consumption in mmol M = Sample size in mL d = Density of sample M = Molar mass of chloride

Waste disposal

Filtration; the precipitate (silver chloride) has to be classified as special waste. The filtrate must be neutralized with sodium hydroxide before disposal.

Author, Version

Vineesh Pallath, IMSG AnaChem, October 2011; Rev. C. De Caro, MSG AnaChem, November 2011


Instruments - Titration Excellence T50/T70/T90, Compact Titrator G20 - Rondo 20 Sample Changer - XP 205 Balance - XP 6 Micro Balance

Accessories - LabX® Titration Pro / Light Software - 1x10mL DV1010 burette, 1x 5mL DV1005 burette, 1x 20mL DV1020 burette - Titration Beaker (100 mL / 250 mL) - Rainin Pipet-Lite L-5000

Results (Potentiometic chloride titration) Potentiometric chloride titration (DMi141-SC): For 10 ppm Chloride: Sample taken - 16.481 mg NaCl 1000 mL solution with deionised water (Theoretical Value: 9.9969 ppm)

For 25 ppm Chloride: Sample taken - 41.620 mg NaCl 1000 mL solution with deionised water (Theoretical Value: 25.2469 ppm)

For 100 ppm Chloride: Sample taken - 0.1662 g NaCl 1000 mL solution with deionised water (Theoretical Value: 100.8178 ppm) Sample preparation for titration:

Required sample to be taken + 10 mL 0.02 M H2SO4 + 2 mL 5% TritonX-100. titrate with 0.01 mol/L AgNO3. Results No. Comment / ID Start time Sample size Results ------------------------------------------------------------------------------------------------------------------------- 1/6 NaCl 8/12/2011 11:18:44 AM 100 mL R1 = 9.9597 ppm Content R2 = 0.001 % Content 2/6 NaCl 8/12/2011 11:24:57 AM 100 mL R1 = 9.9260 ppm Content R2 = 0.001 % Content 3/6 NaCl 8/12/2011 11:30:27 AM 100 mL R1 = 9.9948 ppm Content R2 = 0.001 % Content 4/6 NaCl 8/12/2011 11:38:14 AM 100 mL R1 = 9.9983 ppm Content R2 = 0.001 % Content 5/6 NaCl 8/12/2011 11:44:28 AM 100 mL R1 = 9.9731 ppm Content R2 = 0.001 % Content 6/6 NaCl 8/12/2011 11:50:45 AM 100 mL R1 = 9.9778 ppm Content R2 = 0.001 % Content Statistics Rx Name n Mean value Unit s srel [%] ------------------------------------------------------------------------------------------------------------------------- R1 Content 6 9.9716 ppm 0.0265 0.266 R2 Content 6 0.001 % 0.000 0 Sample Theor.Value Sample size Method ID n RX Name Mean value Unit s srel ppm mL % ------------------------------------------------------------------------------------------------------------------------- 25ppm Cl 25.2469 40 CHLORIDE1 6 R1 Content 25.3493 ppm 0.0245 0.097 R2 Content 0.003 % 0.000 0.0 100ppm Cl 100.8178 20 CHLORIDE 6 R1 Content 100.7740 ppm 0.2377 0.236 R2 Content 0.010 % 0.000 0.0

Titration curve (10 ppm chloride)

Sample 1/6 CHLORIDE 8/12/2011 11:18:15 AM Start time: 8/12/2011 11:18:44


Table of measured values (10 ppm chloride)



0.000 NaN 13.6 NaN NaN 0 25.0

0.008 0.008 13.6 0.0 NaN 3 25.0 0.016 0.008 13.6 0.0 NaN 6 25.0 0.036 0.020 13.9 0.3 NaN 9 25.0 0.086 0.050 14.5 0.6 NaN 12 25.0 0.211 0.125 15.8 1.3 10.44 15 25.0

0.523 0.312 19.1 3.3 11.11 18 25.0

0.923 0.400 24.0 4.9 12.53 21 25.0

1.323 0.400 30.2 6.2 16.38 24 25.0

1.723 0.400 38.2 8.1 23.39 27 25.0

2.123 0.400 48.6 10.3 33.90 30 25.0

2.428 0.305 60.1 11.5 43.14 33 25.0

2.593 0.165 68.7 8.6 47.53 36 25.0

2.716 0.123 75.5 6.8 52.21 40 25.0

EQP1 2.830417 NaN 82.4 NaN 56.04 NaN NaN

2.871 0.155 84.9 9.4 55.97 43 25.0

3.004 0.133 92.9 8.0 51.74 46 25.0

3.156 0.152 101.1 8.2 45.74 49 25.0

3.344 0.188 109.7 8.6 39.66 52 25.0

3.577 0.233 117.5 7.8 32.53 55 25.0

3.937 0.360 126.7 9.2 NaN 59 25.0

4.337 0.400 134.3 7.6 NaN 62 25.0

4.737 0.400 140.3 6.0 NaN 65 25.0

5.137 0.400 144.9 4.6 NaN 68 25.0

5.537 0.400 149.0 4.1 NaN 71 25.0

Comments

• Chloride concentrations above 5 ppm are easily titrated with potentiometric indication using a combined silver ring electrode.

• The use of a non-aquoeus solvent such as acetic acid or acetone can improve the accuracy.

• Chlorides in low concentrations (0.1 ppm. . . 10 ppm) are better titrated with voltametric indication using a polarized double pin electrode.

• Note that the voltametric indication is not recommended for high chloride contents.

• For very low chloride concentrations, AgNO3 0.001 M and/or a 1 ml burette are recommended.

• 1 mL 5% TritonX nonionic surfactant solution is added to the sample to finely disperse the AgCl-precipitate formed during titration.


Results (Voltametric chloride titration) Voltametric chloride titration (DM143-SC): Preparation of sample solutions: 5 ppm chloride (0.01 M AgNO3): 8.781mg NaCl up to 1000 mL with glacial acetic acid (Theoretical value : 5.3266 ppm) 5 ppm (0.0025 M AgNO3): 8.726mg NaCl up to 1000 mL with glacial acetic acid (Theoretical value : 5.2932 ppm) 2.5 ppm (0.0025 M AgNO3): 4.124 mg NaCl up to 1000 mL with glacial acetic acid (Theoretical value : 2.5016 ppm) 1 ppm (0.001 M AgNO3): 1.805 mg NaCl up to 1000 mL with glacial acetic acid (Theoretical value : 1.0949 ppm) 0.5ppm (0.001 M AgNO3): 0.982 mg NaCl up to 1000 mL with glacial acetic acid ( Theoretical Value : 0.5957 ppm) Sample preparation for titration: Required sample to be taken + 100 mL Acetone Titrate. Results (1 ppm) No. Comment / ID Start time Sample size Results ------------------------------------------------------------------------------------------------ 1/6 NaCl 10/20/2011 12:26:31 PM 60 mL R1 = 1.0765 ppm Content 2/6 NaCl 10/20/2011 12:32:30 PM 60 mL R1 = 1.0050 (2) ppm Content 3/6 NaCl 10/20/2011 12:53:40 PM 60 mL R1 = 1.0434 ppm Content 4/6 NaCl 10/20/2011 1:05:16 PM 60 mL R1 = 1.0505 ppm Content 5/6 NaCl 10/20/2011 1:17:12 PM 60 mL R1 = 1.0741 ppm Content 6/6 NaCl 10/20/2011 1:24:16 PM 60 mL R1 = 1.0552 ppm Content (2) - Excluded Statistics Rx Name n Mean value Unit s srel [%] -------------------------------------------------------------------------------------------------R1 Content 5 1.0599 ppm 0.014662 1.383 Sample Theor. value Sample Method ID n Name Mean value s srel size (mL) ppm ppm %

0.5 ppm 0.5957 100 Chloride1ppm16 6 Content 0.5827 0.0093 1.597 2.5 ppm 2.5016 60 Chloride13 6 Content 2.4996 0.0241 0.964 5 ppm 5.2932 30 Chloride5ppm9 6 Content 5.2568 0.0457 0.869 5 ppm 5.3266 100 Chloride5ppm6 6 Content 5.3588 0.0375 0.701


Titration curve (0.5 ppm chloride – voltametric indication – 0.001 M AgNO3)

Chloride1ppm16 Chloride 0.5 ppm G20_16 10/24/2011 11:42:42 AM Start time: 10/24/2011 1:12:34

Table of measured values (0.5 ppm chloride – voltametric indication – 0.001 M AgNO3)



0.00000 NaN 1184.4 NaN NaN 0 25.0

0.05000 0.05000 1304.4 120.0 NaN 13 25.0 0.10000 0.05000 1303.8 -0.6 NaN 18 25.0 0.15000 0.05000 1302.4 -1.4 NaN 24 25.0 0.20000 0.05000 1302.2 -0.2 NaN 29 25.0 0.25000 0.05000 1301.4 -0.8 -156.37 34 25.0

0.30000 0.05000 1300.1 -1.3 -17.29 40 25.0

0.35000 0.05000 1299.7 -0.4 -19.32 46 25.0

0.40000 0.05000 1298.53 -1.2 -22.76 51 25.0

. . . . . . . . . . . . . . . . . . . . .

1.45000 0.05000 1285.9 -1.0 9.77 153 25.0

1.50000 0.05000 1284.6 -1.3 -248.37 176 25.0

1.55000 0.05000 1266.6 -18.0 -382.77 185 25.0

1.60000 0.05000 1235.8 -30.8 -478.11 192 25.0

EQP1 1.645571 NaN 1216.8 NaN -496.88 NaN NaN

1.65000 0.05000 1214.9 -20.9 -498.52 198 25.0

1.70000 0.05000 1185.4 -29.5 -455.25 206 25.0

1.75000 0.05000 1168.8 -16.6 -372.38 214 25.0

1.80000 0.05000 1153.2 -15.6 -302.07 221 25.0

1.85000 0.05000 1141.3 -11.9 -260.15 226 25.0

1.90000 0.05000 1126.2 -15.1 -226.27 235 25.0

1.95000 0.05000 1115.1 -11.1 -260.15 226 25.0

2.00000 0.05000 1106.1 -9.0 -209.62 247 25.0

. . . . . . . . . . . . . . . . . . . . .

2.40000 0.05000 1027.1 -9.9 NaN 292 25.0

2.45000 0.05000 1018.7 -8.4 NaN 298 25.0

2.50000 0.05000 1010.2 -8.5 NaN 304 25.0

2.50000 0.05000 1009.9 -0.3 NaN 309 25.0


Methods Potentiometric titration (10 ppm) 001 Title Type General titration Compatible with T50 / T70 / T90 ID CHLORIDE1 Title CHLORIDE DETERMINATION Author admin Date/Time 8/11/2011 2:44:21 PM Modified at 8/11/2011 3:18:51 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 NaCl Entry type Volume Lower limit 0.0 mL Upper limit 100.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Rondo/Tower A) Type Rondo/Tower A Titration stand Rondo60/1A Lid handling No 004 Dispense(normal) [1] Titrant 5%TRITON Concentration 1 mol/L Volume 2.0 mL Dosing rate 60.0 mL/min Condition No 005 Dispense(normal) [2] Titrant H2SO4 Concentration 0.02 mol/L Volume 10.0 mL Dosing rate 60.0 mL/min Condition No 006 Stir Speed 30 % Duration 30 s Condition No 007 Titration (EQP) [1] Titrant Titrant AgNO3 Concentration 0.01 mol/L Sensor Type mV Sensor DM141-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30 % Predispense Mode None Wait time 0 s Control Control User Titrant addition Dynamic dE (set value) 9.0 mV dV (min) 0.008 mL dV (max) 0.4 mL Mode Equilibrium controlled dE 0.5 mV dt 1.0 s t (min) 3.0 s t (max) 30.0 s Evaluation and recognition Procedure Standard Threshold 50 mV/mL (20 mV/mL) Tendency None Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs 1

Combined termination criteria No Accompanying stating Accompaning stating No Condition Condition No 008 Calculation R1 Result Content Result unit ppm Formula R1=Q*c/m Constant C=M*1000/z M M[Chloride] z z[Chloride] Decimal places 4 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 009 Calculation R2 Result Content Result unit % Formula R2=Q*c/m Constant C=M/(10*z) M M[Chloride] z z[Chloride] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 010 Rinse Auxiliary reagent Water Rinse cycles 1 Vol. per cycle 10 mL Position Current position Drain No Condition No 011 Conditioning Type Fix Interval 1 Position Conditioning beaker Time 60 s Speed 40 % Condition No 012 End of sample


Voltametric titration (0.5 ppm) 001 Title Type General titration Compatible with G20 ID Chloride1ppm16 Title Chloride 0.5 ppm G20_16 Author LabX-Light Date/Time 10/24/2011 11:42:42 AM Modified at 10/24/2011 11:42:42 AM Modified by LabX-Light Protect No SOP None 002 Sample Number of IDs 1 ID 1 NaCl Entry type Volume Lower limit 0.0 mL Upper limit 300.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30 % Duration 10 s 005 Titration (EQP) [1] Titrant Titrant AgNO3 Concentration 0.001 mol/L Sensor Type Polarized Sensor DM143-SC Unit mV Indication Voltametric Ipol[µA] 1.0 Frequency [Hz] 4 Temperature acquisition Temperature acquisition No Stir Speed 20 % Predispense Mode None Wait time 0 s Control Control User Titrant addition Incremental dV 0.05 mL Mode Equilibrium controlled dE 1.0 mV dt 4.0 s t (min) 5.0 s t (max) 30.0 s Evaluation and recognition Procedure Standard Threshold 400 mV/mL Tendency None Ranges 0 Add. EQP criteria Last EQP Last jumps 1 1 Termination At Vmax 2.5 mL At potential No At slope No After number of recognized EQPs No Combined termination criteria No 006 Calculation R1 Result type Predefined Calculation type Direct titration Result Content Result unit ppm Formula R1=Q*c/(m*d) Selected EQP 1 Constant C=M*1000/z M M[Chloride] z z[Chloride] Decimal places 4 Result limits No Record statistics Yes 007 End of sample

Additional results:

1 ppm: Voltametric titration with 0.001 mol/L AgNO3 2.5 ppm: Voltametric titration with 0.0025 mol/L AgNO3 5 ppm: Voltametric titration with 0.0025 mol/L AgNO3 5 ppm: Voltametric titration with 0.01 mol/L AgNO3



Vitamin C Content in Orange Juice: Voltametric Indication Content determination of vitamin C (ascorbic acid) in orange juice by voltametric titration with DPI. The titration is monitored by a polarized DM143 electrode.


The DPI titrant has to be prepared fresh daily. It has to be stored in brown glass bottles to protect it from light. - Ascorbic acid is sensitive to light, temperature and oxygen. Titration beakers with light protection as well as use of purge gas are recommended. Keep in the dark. - Ascorbic acid solution has to be prepared fresh prior to use. 1) Titrant preparation: 0.36 g DPI sodium salt monohydrate (M =

290.08 g/mol) is weighed in a 250 mL volumetric flask and filled up with deionized water to obtain a titrant concentration c(1/2 DPI) = 0.01 mol/L. The flask was placed in an ultrasonic bath during 10 min. to improve solubility.

2) The titer is determined using L(+) ascorbic acid: 5 mL 0.01 mol/L standard solution is added into a titration beaker and diluted with 50 mL deionized water. The pH value is adjusted to pH 3 with 2% oxalic acid by titrating the sample using an EP titration function.

3) The juice is well homogenized and is weighed directly into the titration beaker, without special treatment such as filtration.

4) After addition of 50mL deionized water the sample can be purged with nitrogen gas to avoid oxidation of Vitamin C.

Remarks

1) The method parameters have been optimized for the above mentioned sample. It may be necessary to slightly adapt the method to your specific sample.

2) Both DPI titrant and ascorbic acid standard solution are not stable. To get accurate results, It is recommended to prepare them fresh before use.

Sample 5 g orange juice

Compound L(+) ascorbic acid, C6H8O6 M=176.13 g/mol, z=2

Chemicals 50 mL deionized water 2% oxalic acid for adjustment to pH 3

Titrant 2,6-dichlorophenolindophenol, DPI c(1/2 DPI) = 0.01 mol/L

Standard Ascorbic acid, 0.01 mol/L

Indication DM143-SC

Chemistry L(+)-ascorbic acid is oxidized by DPI: C6H6O6-H2 + DPI → C6H6O6 + H2-DPI Oxidation: C6H8O6 → C6H6O6 + 2H+ + 2e-

Calculation R1=Q*C/m, Content (mg/100g) C=100*M/z R2=Q*C/m, Content (%) C=M/(10*z)

Waste disposal

Neutralize before final disposal as aqueous solution.

Author, Version

Thomas Hitz, July 2006 Market Support Group Anachem


Instruments - T50/T70/T90 Titration Excellence (The G20 Compact Titrator can be used provided major method changes are done)

Accessories - 2 x 10 mL DV1010 burettes - Titration beaker ME-101974 - XS205 Balance - Olivetti Printer JobJet 210

Results All results Method-ID M411 Sample Orange juice (1/1) R1 (Content) 34.713 mg/100 g R2 (Content) 0.0347 % Sample Orange juice (1/2) R1 (Content) 34.227 mg/100 g R2 (Content) 0.0342 % Sample Orange juice (1/3) R1 (Content) 34.887 mg/100 g R2 (Content) 0.0349 % Sample Orange juice (1/4) R1 (Content) 35.367 mg/100 g R2 (Content) 0.0354 % Sample Orange juice (1/5) R1 (Content) 34.896 mg/100 g R2 (Content) 0.0349 % Statistics Method-ID M411 R1 Content Samples 5 Mean 34.816 mg/100 g s 0.334 mg/100 g Srel 0.960 % R2 Content Samples 5 Mean 0.0348 % s 0.0004 % srel 0.960 %

Titration curve



Comments

• The sample size depends on the amount of vitamin C: 1-15 mg vitamin C correspond 0.5 - 8.5 mL 0.01 mol/L 1/2 DPI.

• If DPI sodium salt dihydrate (M=308.08 g/mol) is used, an excess has to be weighed in due to its bad solubility. The titrant has to be filtrated prior to use.

• Orange juice was stored in the refrigerator when not used.

• This method describes the voltametric determination of L(+) ascorbic acid with a polarized sensor DM143-SC. An alternating current of 10-12 μA is applied to the double pin platinum electrode and the potential is measured.

Literature:

- METTLER TOLEDO Applications Brochure 19, ME-51 725 013.


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID M411 Title Vitamin C content Author METTLER TOLEDO Date/Time 02.08.2006 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 Orange juice Entry type Weight Lower limit 0.0 g Upper limit 10.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 35% Duration 10 s Condition No 005 Titration (EQP) [1] Titrant Titrant ½ DPI

Concentration 0.01 mol/L Sensor Type Polarized Sensor DM143-SC Unit mV Indication Voltametric Ipol 12 μA Temperature acquisition Temperature acquisition No Stir Speed 35% Predispense Mode Volume Volume 1.0 mL Wait time 2 s Control Control User Titrant addition Incremental dV 0.05 mL Meas. value acquisition Equilibrium controlled dE 2.0 mV dt 1 s t(min) 2 s t(max) 30 s Evaluation and recognition Procedure Standard Threshold 500 mV/mL Tendency Negative Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 006 Calculation R1 Result Content Result unit mg/100g Formula R1=Q*C/m Constant C=100*M/z M M[Ascorbic acid] z z[Ascorbic acid] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No

Condition No 007 Calculation R2 Result Content Result unit % Formula R2=Q*C/m Constant C=M/(10*z) M M[Ascorbic acid] z z[Ascorbic acid] Decimal places 4 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 008 Record Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V Last titration function log dE/dV – V No d2E/dV2 - V No E - t No V - t No dV/dt - t No T - t No E - V & dE/dV - V No V - t & dV/dt - t No Calibration curve No Method No Series data No Condition No 009 End of sample ------------------------------------------------------------- G20 Compact Titrator Method: .... 006 Calculation R1 Result type Predefined Calculation type Direct titration Formula R1=Q*C/m Selected EQP 1 Result Content Result unit mg/100g Constant C 100*M/z M M[Ascorbic acid] z z[Ascorbic acid] Decimal places 3 Result limits No Record statistics Yes 007 Calculation R2 Result type Predefined Calculation type Direct titration Formula R1=Q*C/m Selected EQP 1 Result Content Result unit % Constant C M/10(*z) M M[Ascorbic acid] z z[Ascorbic acid] Decimal places 4 Result limits No Record statistics Yes ....



Vitamin C Content in Orange Juice: Amperometric Indication Content determination of vitamin C (ascorbic acid) in orange juice by amperometric titration with DPI. The titration is monitored by a polarized DM143 electrode.


The DPI titrant has to be prepared fresh daily. It has to be stored in brown glass bottles to protect it from light. - Ascorbic acid is sensitive to light, temperature and oxygen. Titration beakers with light protection as well as use of purge gas are recommended. Keep in the dark. - Ascorbic acid solution has to be prepared fresh prior to use. 1) Titrant preparation: 0.36 g DPI sodium salt monohydrate (M =

290.08 g/mol) is weighed in a 250 mL volumetric flask and filled up with deionized water to obtain a titrant concentration c(1/2 DPI) = 0.01 mol/L. The flask was placed in an ultrasonic bath during 10 min. to improve solubility.

2) The titer is determined using L(+) ascorbic acid: 5 mL 0.01 mol/L standard solution is added into a titration beaker and diluted with 50 mL deionized water. The pH value is adjusted to pH 3 with 2% oxalic acid by titrating the sample using an EP titration function.

3) The juice is well homogenized and is weighed directly into the titration beaker, without special treatment such as filtration.

4) After addition of 50mL deionized water the sample can be purged with nitrogen gas to avoid oxidation of Vitamin C.

Remarks


2) Both DPI titrant and ascorbic acid standard solution are not stable. To get accurate results, It is recommended to prepare them fresh before use.

Sample 5 g orange juice

Compound L(+) ascorbic acid, C6H8O6 M=176.13 g/mol, z=2

Chemicals 50 mL deionized water 2% oxalic acid for adjustment to pH 3

Titrant 2,6-dichlorophenolindophenol, DPI c(1/2 DPI) = 0.01 mol/L

Standard Ascorbic acid, 0.01 mol/L

Indication DM143-SC

Chemistry L(+)-ascorbic acid is oxidized by DPI: C6H6O6-H2 + DPI → C6H6O6 + H2-DPI Oxidation: C6H8O6 → C6H6O6 + 2H+ + 2e-

Calculation Content (mg/100g) R1=Q*C/m, C=100*M/z

Waste disposal

Neutralize before final disposal as aqueous solution.

Author, Version

Claudia Schreiner, July 2006 Market Support Group Anachem


Instruments - T50/T70/T90 Titration Excellence - XS205 Balance

Accessories - 2 x 10 mL DV1010 burettes - Titration beaker ME-101974 - Olivetti Printer JobJet 210

Results All results Method-ID M412 Sample Orange juice (1/1) R1 (Content) 24.0989 mg/100 g Sample Orange juice (1/2) R1 (Content) 23.9783 mg/100 g Sample Orange juice (1/3) R1 (Content) 24.5614 mg/100 g Sample Orange juice (1/4) R1 (Content) 23.5523 mg/100 g Sample Orange juice (1/5) R1 (Content) 23.5976 mg/100 g Sample Orange juice (1/6) R1 (Content) 24.3256 mg/100 g Statistics Method-ID M412 R1 Content Samples 6 Mean 24.0190 mg/100 g S 0.3979 mg/100 g

Titration curve



Comments

• The sample size depends on the amount of vitamin C: 1-15 mg vitamin C correspond 0.5 - 8.5 mL 0.01 mol/L 1/2 DPI.

• If DPI sodium salt dihydrate (M=308.08 g/mol) is used, an excess has to be weighed in due to its bad solubility. The titrant has to be filtrated prior to use.

• Orange juice was stored in the refrigerator when not used.

• This method describes the amperometric determination of L(+) ascorbic acid with a polarized sensor DM143-SC. A polarization voltage of 200 mV is applied to the double pin platinum electrode and the current is monitored during titration.

Literature:

- METTLER TOLEDO Applications Brochure 19, ME-51 725 013.


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID M412 Title Vitamin C content Author METTLER TOLEDO Date/Time 02.08.2006 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 Orange juice Entry type Weight Lower limit 0.0 g Upper limit 10.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary180 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 35% Duration 10 s Condition No 005 Titration (EQP) [1] Titrant Titrant ½ DPI

Concentration 0.01 mol/L Sensor Type Polarized Sensor DM143-SC Unit µA Indication Amperometric Ipol 200 mV Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Control User Titrant addition Incremental dV 0.1 mL Meas. value acquisition Equilibrium controlled dE 0.3 µA dt 2 s t(min) 5 s t(max) 30 s Evaluation and recognition Procedure Segmented Threshold 1 µA/mL2

Ranges 1 Lower limit 0.6 µA Upper limit 10.0 µA Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No

006 Calculation R1 Result Content Result unit mg/100g Formula R1=Q*C/m Constant C=100*M/z M M[Ascorbic acid] z z[Ascorbic acid] Decimal places 4 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 007 Record Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V No log dE/dV – V No d2E/dV2 - V Last titration function E - t No V - t No dV/dt - t No T - t No E - V & dE/dV - V No V - t & dV/dt - t No Calibration curve No Method No Series data No Condition No 008 End of sample



Free Sulphur Dioxide (SO2) Content in Wine The content of free sulphur dioxide (SO2) in wine is determined by redox titration with iodine as a titrant. The titration is monitored using a Pt double pin electrode DM143 at a fixed polarization current (voltametric indication).


Note:

This method allows a fully automated analysis procedure by using two additional burette drives.

1) The titer determination is performed using pure ascorbic acid as a primary standard.

2) Sample determination: 50 mL wine is transferred into a titration beaker with a pipette.

3) 5 mL 10% potassium iodide solution are added. This step has been performed using an additional dosing unit. It can be performed manually using a pipette.

4) 5 mL 20% sulfuric acid is added to the titration beaker. This step has been performed using an additional dosing unit. If this is not possible, this step can be done manually with a pipette.

Note:

Sodium metabisulfite (Na2S2O5, M = 222.32 g/mol) can be used as a SO2-standard: 1 Na2S2O5 → 2 SO2

Remarks


2) In order to avoid loss of SO2, the samples must be taken from a freshly opened bottle. After opening the bottle, free SO2 can evaporate with CO2 or be oxidized while in contact with air resulting in too low results.

3) Working with the sample changer leads to SO2 losses from the sample beakers already prepared on the rack. Therefore it is recommended to work without a sample changer to achieve a higher accuracy.

Sample 50 mL white wine

Compound Sulphur dioxide, SO2 M = 64.06 g/mol, z = 2

Chemicals 5 mL 10% potassium iodide, KI 5 mL 20% sulfuric acid, H2SO4

Titrant Iodine, I2 c(1/2 I2) = 0.02 mol/L

Standard Ascorbic acid, C6H8O6, M=176.13 g/mol

Indication DM143-SC

Chemistry SO2 + I2 + 2 H2O → H2SO4 + 2 HI

Calculation R1: Content (mg/L)

R1=Q*C/m, C=M*1000/z

Waste disposal

Neutralize the acid waste before final disposal.

Author, Version

Claudia Schreiner, July 2006 Market Support Group Anachem


Instruments - T50/T70/T90 Titration Excellence - 2 additional dosing units - G20 Compact Titrator ( max. 1 dosing unit; with major changes in titration method) - XS205 Balance Accessories - 3 x 10 mL DV1010 burettes - Titration beaker ME-101974 - Olivetti Printer JobJet 210

Results All results Method-ID M419 Sample White wine (1/1) R1 (Content) 21.222 mg/L Sample White wine (1/2) R1 (Content) 21.294 mg/L Sample White wine (1/3) R1 (Content) 21.160 mg/L Sample White wine (1/4) R1 (Content) 21.114 mg/L Sample White wine (1/5) R1 (Content) 21.190 mg/L Sample White wine (1/6) R1 (Content) 21.127 mg/L Statistics Method-ID M419 R1 Content Samples 6 Mean 21.185 mg/L s 0.067 mg/L srel 0.315 %

Titration curve



Comments

• Iodine is also reduced by other wine components. These competing reactions can partly be delayed by the addition of 5 mL 10% potassium iodide solution.

• The reaction only takes place in acidic medium. Therefore, 5 mL 20% H2SO4 must be added immediately before titration.

• If the sample contains ascorbic acid the amount of SO2 will be higher, because of the reaction from ascorbic acid with iodine.


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID M419 Title Free SO2 content in wine Author METTLER TOLEDO Date/Time 02.08.2006 15:00:00 Modified at -- Modified by -- Protect No SOP None 002 Sample Number of IDs 1 ID 1 White wine Entry type Fixed volume Volume 50.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Dispense (normal) [1] Titrant 10% KI

Concentration 1 mol/L Volume 5.0 mL Dosing rate 60.0 mL/min 005 Dispense (normal) [2] Titrant 20% H2SO4

Concentration 1 mol/L Volume 5.0 mL Dosing rate 60.0 mL/min 006 Stir Speed 50% Duration 10 s Condition No 007 Titration (EP) [1] Titrant Titrant ½ I2

Concentration 0.02 mol/L Sensor Type Polarized Sensor DM143 Unit mV Indication Voltametric Ipol 10 µA Temperature acquisition Temperature acquisition No Stir Speed 50% Predispense Mode None Wait time 10 s Control Control User End point type Absolute Tendency Negative Endpoint value 100 mV Control band 30 mV Dosing rate (max) 1.25 mL/min Dosing rate (min) 100 μL/min Termination At EP Yes Termination delay 5 s At Vmax 10.0 mL Max. time 600 s 008 Calculation R1 Result Content Result unit mg/L Formula R1=Q*C/m Constant C=M*1000/z M M[Sulfur dioxide] z z[Sulfur dioxide] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No

009 Record Results Per series Raw results Per series Table of meas. values Last titration function Sample data Per series Resource data No E - V Last titration function dE/dV - V Last titration function log dE/dV – V No d2E/dV2 - V No E - t No V - t No dV/dt - t No T - t No E - V & dE/dV - V No V - t & dV/dt - t No Calibration curve No Method No Series data No Condition No 010 End of sample ------------------------------------------------------------- G20 Compact Titrator Method: The G20 method includes slightly modifications: ... 008 Calculation R1 Result type Predefined Calculation type Direct titration Formula R1=Q*C/m Result Content Result unit mg/L Constant C M*1000/z M M[Sulfur dioxide] z z[Sulfur dioxide] Decimal places 3 Result limits No Record statistics Yes ....


METTLER TOLEDO Application M564

Total Sulfur Dioxide in Wines The total amount of sulfur dioxide in wines is determined by redox titration with iodine as a titrant. Two techniques are illustrated: 1.) the voltametric indication with a platinum double-pin polarized electrode, and 2.) the standard potentiometric indication with a combined platinum ring electrode.

Preparation and Procedures CAUTION ‐ Use safety goggles, a lab coat and wear gloves. ‐ Ensure accurate cleaning of sensor is sufficient

after each titration.

Titer determination: ‐ Weigh 0.1 g ascorbic acid in a 100 mL volume-

tric flask, add 30 mL deion. water to dissolve it. ‐ Fill up to the mark with water and pipette 10 mL

into the titration beaker for titer determination. ‐ Add 50 mL deion. water, 5 mL 25% H2SO4 and

0.5 g KI (or 10 mL 10% KI solution). ‐ Start immediately* the titer determination.

Sample preparation and titration: ‐ Fill the titration beaker with 50 mL wine. ‐ Add 5 mL 5 mol/L NaOH to liberate SO2. ‐ Allow the beaker to stand for 15 minutes. ‐ Add 7 mL 25% v/v H2SO4 ‐ Add 0.5 g potassium iodide (KI) or 10 mL of 10%

KI in water and start immediately* the titration. * Under strong acidic conditions, KI will convert to iodine with oxygen. Thus, the titration should start immediately after the KI addition.

Indication: ‐ Two different indications are used to monitor the

titrations, i.e. a potentiometric and a voltametric technique (see “Comments”).

Remarks

‐ The application method has been developed for the mentioned sample. It may be necessary to optimize the method for your sample.

‐ A sample changer may be used for a fully automatic procedure. The method can easily be modified for operation with a sample changer by defining it correspondingly in the method.

‐ Literature: Application M419, Swiss Food Manual (www.slmb.bag.admin.ch)

Sample - Californian red wine, 50 mL - Various European wines,

50 mL Compound Sulfur dioxide, SO2

M = 64.06 g/mol, z = 2

Chemicals 5 mol/L NaOH 25% v/v H2SO4 Potassium iodide, KI Deionized water

Titrant Iodine, I2 c(½ I2) = 0.02 mol/L , z = 2

Standard Ascorbic acid, C6H8O6 M = 176.13 g/mol , z = 2 0.1 g/100 mL (10 mL aliquot)

Indication - Method 1: DGi140-SC combined redox electrode

- Method 2: DG143-SC Platinum double-pin electrode

Chemistry Titer determination: C6H8O6 + I2 → C6H6O6 + 2 I- + 2 H+

Sample determination: I2 + SO2 + 2 H2O → 4 H+ + 2 I- + SO4

2-

Calculation Consumption: R1 = VEQ, in mL C = 1 Total SO2: R2 = Q*C/m, in ppm C = M*1000/z

Waste disposal

Neutralize the titrated solutions before final disposal

Author, Version

Matt Eby, Marketing AnaChem, Version 2.0



Instruments ‐ Titration Excellence T50/T70/T90 (Other titrators: depending on instrument type, manual operation and method changes are necessary)

‐ 1 x 10 mL DV1010 glass burette

Accessories ‐ XS205 Balance ‐ PP Titration beakers ‐ LabX® titration software

Results Method 2 - Potentiometric indication with combined platinum ring redox electrode DMi140-SC Wine: Cabernet Sauvignon - California All results Method-ID m564TxA Sample Total SO2 (1/3) R1 (Consumption) 1.253 mL R2 (Total SO2) 32.12 ppm Sample Total SO2 (2/3) R1 (Consumption) 1.252 mL R2 (Total SO2) 32.09 ppm Sample Total SO2 (3/3) R1 (Consumption) 1.228 mL R2 (Total SO2) 31.47 ppm Statistics Method-ID m564TxA R2 Total SO2 Samples 3 Mean 31.89 ppm s 0.366924 ppm srel 1.150 %

Titration curve

Sample 1/3



Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C 0 NaN 197.4 NaN NaN 0 25 0.02 0.02 196.2 ‐1.2 NaN 3 25 0.04 0.02 195.7 ‐0.5 NaN 6 25 0.06 0.02 195.2 ‐0.5 NaN 9 25 0.08 0.02 194.7 ‐0.5 NaN 12 25 0.1 0.02 194.3 ‐0.4 ‐20.46 15 25 0.12 0.02 193.8 ‐0.5 ‐21.79 18 25 0.14 0.02 193.4 ‐0.4 ‐20.71 21 25 0.16 0.02 193 ‐0.4 ‐20 24 25 . . . . . . . . . . . . . . . . . . . . . 0.98 0.02 185.4 0 1.2 148 25 1 0.02 185.5 0.1 1.84 151 25 1.02 0.02 185.5 0 4.4 154 25 1.04 0.02 185.6 0.1 7.74 157 25 1.06 0.02 185.8 0.2 3.32 160 25 1.08 0.02 186 0.2 14.33 163 25 1.1 0.02 186.5 0.5 11.77 166 25 1.12 0.02 186.8 0.3 23.4 169 25 1.14 0.02 187.2 0.4 54.58 172 25 1.16 0.02 190.4 3.2 94.18 175 25 1.18 0.02 191 0.6 245.05 178 25 1.2 0.02 198.5 7.5 483.73 181 25 1.22 0.02 207.4 8.9 710.64 184 25 1.24 0.02 221.3 13.9 848.45 187 25

EQP1 1.253409 NaN 239.5 NaN 863.81 NaN NaN 1.26 0.02 248.5 27.2 861.7 190 25 1.28 0.02 265.7 17.2 734.65 193 25 1.3 0.02 274.5 8.8 543.79 196 25 1.32 0.02 280.9 6.4 334.14 199 25 1.34 0.02 286 5.1 191.66 202 25 1.36 0.02 290.2 4.2 NaN 205 25 1.38 0.02 293.7 3.5 NaN 208 25 1.4 0.02 296.5 2.8 NaN 211 25 1.42 0.02 299 2.5 NaN 214 25 1.44 0.02 301 2 NaN 217 25

Sample 1/3

Comments

General: • This method allows for the determination of the total sulfur dioxide content in red and white wines by

direct titration with iodine. The total SO2-content is defined as the sum of the free SO2 and the SO2 bound to other substances contained in the wine, i.e. aldehydes, ketones, etc.

• As in the determination of free SO2 in wine (see M419) the samples must be taken from a freshly opened bottle to avoid loss of SO2.

• To avoid binding of SO2 to organic compounds, a fast titration is required (2-3 minutes); particularly for wines with high SO2 content otherwise a lower value will be determined.

• Performing free and total SO2 titration manually typically results in a high value, due to visual determination past the true endpoint. Using the Ripper method with a titration sensor (DMi140-SC or DM143-SC) avoids this error by recognizing the endpoint when the SO2 is actually neutralized.

Indication: Two different techniques have been used for the determination in different wines:

• Potentiometric indication with a combined platinum ring redox electrode (DMi140-SC): o Wines such as Californian red wines may contain a large amount of tannins. Their presence

affects the results of voltametric indication and can delay the endpoint, leading to higher values when compared to AO (Aeration Oxidation) techniques.

o The method parameters have been optimized for a quick and accurate determination of the total SO2 content. This analysis concept can also be applied to free SO2 analysis.

• Voltametric indication with polarized platinum double-pin electrode (DM143-SC): o Several wines have been analyzed by titration with iodine and voltametric indication. o The voltametric indication is generally recommended for the determination of SO2


Results Method 2 - Voltametric indication with platinum double-pin redox electrode DM143-SC (Method M564TxB) Wine: Dôle, La Valaisanne - Valais (Switzerland) All results

No. ID Sample size and results

1 wine 50.0 mL

R1 = 5.627 mL

R2 = 72.875 mg/L SO2

2 wine 50.0 mL

R1 = 5.701 mL

R2 = 73.834 mg/L SO2

3 wine 50.0 mL

R1 = 5.643 mL

R2 = 73.083 mg/L SO2

4 wine 50.0 mL

R1 = 5.681 mL

R2 = 73.575 mg/L SO2

Statistics Number of results R2 n = 4

Mean value x = 73.342 mg/L SO2

Standard deviation s = 0.44008 mg/L SO2

Rel. standard deviation srel = 0.600 %

Results of total sulfur dioxide determination in various samples: Sample n mean srel reference*

[mg/L] [%] [mg/L]

---------------------------------------------------------------

Spanish red wine 5 135.28 2.34 40 - 120

Swiss red wine 4 73.34 0.60 40 - 120

White wine 3 86.42 1.44 60 - 150

*Swiss Food Manual (www.slmb.bag.admin.ch)



Methods Method 1 - Potentiometric indication with DMi140-SC 001 Title Type General titration Compatible with T50 / T70 / T90 ID m564TxA Title Total SO2 content in wine . . . . . . Protect No SOP None 002 Sample Number of IDs 1 ID 1 Calif. Cabernet Sauvignon Entry type Fixed volume Volume 50.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 20 s Condition No 005 Titration (EQP) [1] Titrant Titrant ½ I2

Concentration 0.02 mol/L Sensor Type mV Sensor DM140-SC Unit mV Temperature acquisition Temperature measurement No Stir Speed 30% Predispense Mode None Wait time 0 s Control Control User Titrant addition Incremental dV 0.02 mL Mode Fixed time dt 3 s Evaluation and recognition Procedure Standard Threshold 50 mV/mL Tendency Positive Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No 006 Calculation R1 Result Consumption Result unit mL Formula R1=VEQ Constant C=1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No

007 Calculation R2 Result Total SO2

Result unit ppm Formula R2=Q*C/m Constant C=M*1000/z M M[Sulfur dioxide] z z[Sulfur dioxide] Decimal places 2 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 008 End of sample


Method 2 - Voltametric indication with DM143-SC 001 Title Type General titration Compatible with T50 / T70 / T90 ID m564TxB Title Total SO2 content in wine Author METTLER TOLEDO . . . . . . Protect No SOP None 002 Sample Number of IDs 1 ID 1 Wine Entry type Fixed volume Volume 50.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 20 s Condition No 005 Titration (EP) [1] Titrant Titrant ½ I2

Concentration 0.02 mol/L Sensor Type Polarized Sensor DM143 Unit mV Indication Voltametric Ipol 10 µA Temperature acquisition Temperature measurement No Stir Speed 30% Predispense Mode None Wait time 0 s Control Control User End point type Absolute Tendency Negative Endpoint value 100 mV Control band 30 mV Dosing rate (max) 1.25 mL/min Dosing rate (min) 100 μL/min Termination At EP Yes Termination delay 5 s At Vmax 10.0 mL Max. time 600 s 006 Calculation R1 Result Consumption Result unit mL Formula R1=VEQ Constant C=1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No

007 Calculation R2 Result Total SO2

Result unit mg/L Formula R2=Q*C/m Constant C=M*1000/z M M[Sulfur dioxide] z z[Sulfur dioxide] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 008 End of sample


METTLER TOLEDO Application M051-2012 Iodine Value determination of Fats and Oils according to Wijs (AOAC 993.20) Method for determining the Iodine value of fats and oils according to Wijs is based on recommendations of AOAC 993.20 standard.


- Weigh 0.10-0.15 g of sunflower oil in a 100 mL titration beaker

- Add 10 mL of prepared solvent (1:1)

- Add 10 mL Wijs solution c(ICl)= 0.1 mol/L, mix thoroughly and keep the solution in the dark at room temperature for approx. 1 hour to complete the reaction

- Add 10 mL of 15% KI and 5mL deionized water

- Titrate immediately with 0.1 mol/L Na2S2O3

Chemicals preparation: Solvent (1:1, v:v) 500 mL acetic acid+ 500 mL cyclohexane

Potassium iodide, 20% (m/v) Dissolve 20 g potassium iodide in 100 mL deionized water.

CAUTION:

- Work in a fume hood and use safety Goggles, wear gloves and a lab coat.

- Mercury (ll) acetate (see Remarks below) is highly toxic!

Remarks

- The iodine value is the amount of iodine in g which reacts with the carbon double bonds (unsaturated bonds) in 100 g of sample

- The sample size as well as the reaction time in the dark depends on the expected iodine value of the sample (IV <150, 1.0 h; IV >150, 2.0 h)

- The addition of 10 mL 2.5% mercury(II) acetate in glacial acetic acid (after Wijs solution is added) shortens the reaction time to 3-5 minutes.

Literature: 1. AOAC Official Methods of Analysis (2010),

Method 993.20. 2. Appl. Brochure No.18 Memory Card Package

‘Standardization of titrants', 2005. 3. Mettler-Toledo Applications M526, M617.

Sample Sunflower oil

Compound Unsaturated compounds, double bonds (-CH=CH-)

Chemicals - Cyclohexane:acetic acid (1:1) - 15% potassium iodide - Deionized water - 2.5% mercuric(ll) acetate in glacial acetic acid (optional)

Titrant Sodium thiosulfate, Na2S2O3 c(Na2S2O3)=0.1 mol/L; For standardization refer to application M-526

Standard Potassium iodate, KIO3 M = 213.99 g/mol, z = 6

Indication DMi140-SC Combined platinum ring electrode

Chemistry ICl3 + I2 → 3 ICl

ICl + KI → I2 + KCl

2(S2O3)2- + I2 → 2 I- + (S4O6)2-

Calculation R1 = (B[Back Wijs]-Q)*C/m

C = M/(10*z) Q = Titrant consumption in

mmol m = Sample size in gram

Waste disposal

Halogenated organic waste.

Author Vineesh Pallath, IMSG, March 2012 Revised: Valeria Gärtner, MSG AnaChem, May 2012


Instruments - T50/T70/T90 Titration Excellence - 2 x DV1020 burette 20 ml (MT-51107502) - Additional dosing unit (ME-51109030)

Accessories - LabX® pro software - 100 ml Titration beaker (ME-101974) - Rainin 10 ml pipette

Results Results Sample No. Comment / ID Sample size (g) results

1/6 Sunflower Oil 0.10674 R1 = 129.75186

2/6 Sunflower Oil 0.10612 R1 = 129.97863

3/6 Sunflower Oil 0.12728 R1 = 129.85804

4/6 Sunflower Oil 0.13121 R1 = 129.84691

5/6 Sunflower Oil 0.10543 R1 = 129.96556

6/6 Sunflower Oil 0.12529 R1 = 129.57534

Statistics Method-ID M051 R1 6 Samples 6 Mean 129.82939 s 0.149997 srel 0.116% Results Back Value Wijs Method-ID M051

Sample Size 10 mL Sample Back Wijs (1/3)

R1 1.913 mmol Sample Back Wijs (2/3) R1 1.915 mmol Sample Back Wijs (3/3) R1 1.913 mmol Statistics Method-ID M051 R1 3 Samples 3 Mean 1.913 mmol s 0.002 srel 0.080%


Titration curve (Sample) E-V curve, EQP titration

Titration curve (Back value Wijs) E-V curve, EQP titration


Table of measured values (sample) Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C 0 NaN 266.8 NaN NaN 0 25 0.03 0.03 266.8 0 NaN 64 25 0.06 0.03 266.8 0 NaN 67 25 0.135 0.075 267 0.2 NaN 70 25 0.3225 0.1875 267.3 0.3 NaN 74 25 0.7915 0.469 268.1 0.8 1.48 78 25 --- --- --- --- --- --- 25 7.9105 0.119 242.7 -4.2 -68.82 141 25 7.992 0.0815 237.6 -5.1 -179.12 145 25 8.0925 0.056 227.5 -6.8 -457.07 153 25 8.1225 0.03 221.5 -6 -489.84 156 25 8.1525 0.03 209.2 -12.3 -692.38 160 25 EQP1 8.174023 NaN 160.1 NaN -719.81 NaN NaN 8.1825 0.03 140.7 -68.5 -718.81 181 25 8.2125 0.03 120.9 -19.8 -499.11 196 25 8.2425 0.03 112.2 -8.7 -474.82 207 25 8.2815 0.039 106 -6.2 -374.61 216 25 8.3385 0.057 100.7 -5.3 NaN 224 25 8.432 0.0935 95.6 -5.1 NaN 233 25 8.587 0.155 91 -4.6 NaN 240 25 8.8885 0.3015 85.8 -5.2 NaN 249 25 9.3885 0.5 80.7 -5.1 NaN 258 25

Table of measured values (Back value Wijs)

Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C 0 NaN 282.2 NaN NaN 0 25 0.03 0.03 282.1 -0.1 NaN 64 25 0.06 0.03 282.4 0.3 NaN 67 25 0.135 0.075 282.7 0.3 NaN 70 25 0.3225 0.1875 283.2 0.5 NaN 74 25 0.7915 0.469 284.4 1.2 2.66 78 25 --- --- --- --- --- --- 25 18.907 0.059 257.3 -4.4 -301.39 270 25 18.957 0.05 251.4 -5.9 -436.86 274 25 18.987 0.03 245.9 -5.5 -462.04 278 25 19.017 0.03 235.9 -10 -658.75 282 25 EQP1 19.03572 NaN 199.5 NaN -660.87 NaN NaN 19.047 0.03 177.5 -58.4 -600.84 295 25 19.077 0.03 146.3 -31.2 -458.77 314 25 19.107 0.03 137.5 -8.8 -476.62 324 25 19.168 0.061 129.2 -8.3 -324.27 334 25 19.2455 0.0775 123.4 -5.8 NaN 343 25 19.3705 0.125 118.3 -5.1 NaN 351 25 19.5935 0.223 112.9 -5.4 NaN 360 25 19.938 0.3445 107.5 -5.4 NaN 369 25 20.438 0.5 99.4 -8.1 NaN 402 25


Comments - The iodine monochloride (Wijs solution) is added in excess to the fat or oil sample to halogenate the

double bonds. The excess iodine monochloride is then reduced to iodine by the addition of KI and the generated iodine is titrated with sodium thiosulfate.

- The determination of the iodine value is done by back titration. Therefore, the back value of the Wijs solution has to be determined first (see methods below).

- The method parameters have been optimized for the above sample. It may be necessary to slightly adapt this method for your specific samples.

- Clean the electrode thoroughly with deionized water after every titration.

Method Sample Sample 001 Title Type General titration Compatible with T50/T70/T90 ID M051 Title IODINE VALUE Author admin Date/Time 3/27/2012 4:52:30 PM Modified at 3/27/2012 4:52:30 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 Sunflower Oil Entry type Weight Lower limit 0.0 g Upper limit 5.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand1 004 Dispense (normal) [1] Titrant 15% KI Concentration 1 Volume 10 mL Dosing rate 60.0 mL/min Condition No 005 Instruction Instruction Add 5mL Water Mode Confirmation Print Yes LabX command No Condition No 006 Stir Speed 30% Duration 60 s Condition No

007 Titration (EQP) [1] Titrant Titrant Na2S2O3 Concentration 0.1 mol/L Sensor Type mV Sensor DM140-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 60 s Control Control User Titrant addition Dynamic dE(set value) 5.0 mV dV(min) 0.03mL dV(max) 0.5 mL Mode Equilibrium controlled dE 1.0 mV dt 3.0 s t(min) 2.0 s t(max) 60.0 s Evaluation and recognition Procedure Standard Threshold 200 Tendency None Ranges 0 Add. EQP criteria No Termination At Vmax 60.0 At potential No At slope No After number of recognized EQPs Yes Number of EOPs 1 Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No 008 Calculation R1 Result Content Result unit g I2/100 g Formula R1=(B[Back Wijs]-Q)*C/m Constant C= 12.69 M M[None] z z[None] Decimal places 5 Result limits No Record Statistics Yes Extra statistical Functions No Send to buffer No Condition No 009 End of sample


Method Back Value Wijs Blank Value Wijs 001 Title Type General titration Compatible with T50/T70/T90 ID M051 Title Back Wijs Author admin Date/Time 3/27/2012 3:40:10 PM Modified at 3/27/2012 4:01:33 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 Back Entry type Fixed volume Fixed volume 10 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand1 004 Dispense (normal) [1] Titrant 15% KI Concentration 1 Volume 10 mL Dosing rate 60.0 mL/min Condition No 005 Instruction Instruction Add 5mL Water Mode Confirmation Print Yes LabX command No Condition No 006 Stir Speed 30% Duration 60 s Condition No 007 Titration (EQP) [1] Titrant Titrant Na2S2O3 Concentration 0.1 mol/L Sensor Type mV Sensor DM140-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 60 s Control Control User Titrant addition Dynamic dE(set value) 5.0 mV dV(min) 0.03mL dV(max) 0.5 mL Mode Equilibrium controlled dE 1.0 mV dt 3.0 s t(min) 2.0 s t(max) 60.0 s Evaluation and recognition Procedure Standard Threshold 200 Tendency None Ranges 0 Add. EQP criteria No Termination At Vmax 60.0 At potential No At slope No After number of recognized EQPs Yes Number of EOPs 1 Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No

008 Calculation R1 Result Consumption Result unit mmol Formula R1=Q Constant C= 1 M M[None] z z[None] Decimal places 3 Result limits No Record Statistics Yes Extra statistical Functions No Send to buffer No Condition No 009 End of sample 010 Blank Name Back Wijs Value B= Mean[R1] Units mmol Limits No Condition No



Saponification Value of Edible Oils and Fats Method for the determination of the saponification value of edible oils and fats. The saponification value is obtained by back titration of excess potassium hydroxide with hydrochloric acid after saponification at high temperature. The titration is monitored with a combined pH glass electrode with fixed sleeve.

Preparation and Procedures Precautions: • Use safety goggles, gloves and a lab coat while

working in a lab. If possible work in a fume hood. • Ensure the cleaning of the electrode especially

while titrating with margarine. Preparations:

• Sample preparation of oil: ‐ Weigh 2 - 2.5 g of sample in a glass titration

beaker and place it on a rondo rack then place a reflux condenser onto rondo head by using adapter and connect a water circulating bath to the condenser to maintain the room temperature.

‐ Add 40 mL of ethanol with membrane pump of sample changer.

‐ Add 25 mL of 0.5 mol/L alcoholic KOH with additional dosing burette.

‐ Reflux the sample by heating it at 75 °C with (automatic heating device) DH100 for 30 minutes with constant stirring.

‐ Titrate with 0.5 mol/L HCl.

• Back Value: ‐ The back value is determined under the same

conditions but without sample. ‐ The mean value of 3 determinations is stored

as back value B[BackEQP] and used in the method for the titration of the sample.

Remarks

• Boiling the sample helps to dissolve the oil or fat. This allows automation.

• Attention has to be paid to the burette tips and the electrode. o The burette tip of the KOH solution must not

be immersed into the boiling ethanol or the reagent will boil, too.

o The burette tip of the titrant should just touch the level of the solution. Otherwise, increased diffusion - due to the high temperatures - will have a negative influence on the accuracy of the results.

The condensed ethanol dribbling down the burette tip rinses the last drop of reagent into the solution anyway.

Sample Oil, fat, margarine

Compound Acidic groups, R – COOH

Chemicals Absolute alcohol (Ethanol) Hydrochloric acid, HCl Potassium hydroxide in ethanol

Titrant Hydrochloric acid, HCl, c(HCl) = 0.5 mol/L Potassium hydroxide in ethanol KOH in EtOH, c(KOH) = 0.5 mol/L

Standard THAM (TRIS) Tris(hydroxymethyl)-aminomethan (HCl) Standardized HCl (for KOH)

Indication DGi115-SC combined pH glass electrode (fixed sleeve)

Chemistry 1) R-COOH + KOH → R-COOK + H2O

2) KOH (excess) + HCl → KCl + H2O

Calculation Saponification Value (mg KOH/g) R1 = (B[BackEQP]-Q)*C/m C = M/z M(KOH) = 56.11 g/mol z = 1 Back Value (mmol) R1 = Q ; C = 1

Waste disposal

Neutralization before final disposal of organic waste.

Author, Version

Sohel Ansari, IMSG, July 2012 Revised: C. De Caro, MSG AnaChem, July 2012


Instruments ‐ T50/T70/T90 Titration Excellence – (other titrators: with modifications or manual op.) ‐ 1 x Dosing Unit (MT-51109030) ‐ 2 x DV1020 burettes 20 mL (MT-51107502) ‐ Rondo20 with PowerShower™ (MT-51108003) ‐ DH100 Heating System (MT-51108780)

Accessories ‐ Glass titration beaker (ME-00101446) ‐ LabX®pro titration software ‐ XP205 Balance ‐ Water circulating bath (third party accessory) ‐ Reflux condenser with adapter (third party accessory)

Results Sap Value of Sunflower oil STATISTICS

Number of results R1 n = 6 Mean value x = 186.272 mgKOH/g Sap Value Standard deviation s = 0.123 mgKOH/g Sap Value Rel.standard deviation srel = 0.066 %

Back Value STATISTICS

Number of results R1 n = 3 Mean value x = 12.103 mmoL Standard deviation s = 0.004 mmoL Rel.standard deviation srel = 0.034 %

Sample Sample Mass

[g] n Mean value

[mgKOH/g] Std.

Deviation [mgKOH/g]

srel

[%]

Literature Reference [mgKOH/g]

Sunflower Oil 2.5151 - 2.5713 6 186.272 0.123 0.066 185 - 198

Coconut Oil 1.9312 - 2.0271 5 247.608 0.714789 0.289 250 - 264

Palm Oil 2.0080 - 2.0969 6 192.728 0.522 0.271 190 - 205

Olive Oil 2.5304 - 2.5769 4 185.806 0.215696 0.116 184 - 196 Peanut Oil 2.5063 - 2.5659 6 183.330 0.355 0.194 190

Margarine 2.1358 - 2.4492 7 162.753 1.104 0.678 190

Titration curve

Back Value determination Sample Titration


Table of measured values Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C 0.000 NaN -404.9 NaN NaN 0 76.5 0.050 0.050 -404.2 0.7 NaN 2 76.4 0.100 0.050 -403.8 0.4 NaN 4 76.4 0.225 0.150 -402.7 1.1 NaN 6 76.3 0.375 0.150 -401.3 1.4 NaN 8 76.2 0.525 0.150 -399.9 1.4 9.94 10 76.1 0.675 0.150 -398.5 1.4 10.43 12 75.9 0.825 0.150 -396.8 1.7 10.66 14 75.7 0.975 0.150 -395.1 1.7 10.82 16 75.6 1.125 0.150 -393.5 1.6 10.85 18 75.4 1.275 0.150 -392.0 1.5 10.57 20 75.2 1.425 0.150 -390.4 1.6 10.26 22 75.0 1.575 0.150 -388.8 1.6 10.24 24 74.8 ------------- ---------- ----------- ---------- ----------- ------- -------- 7.482 0.050 -262.1 7.2 230.19 109 67.8 7.532 0.050 -254.0 8.1 304.01 111 67.6 7.582 0.050 -241.5 12.5 466.39 114 67.5 7.632 0.050 -220.4 21.1 636.95 118 67.3

EQP 7.681263 NaN -169.0 NaN 686.75 NaN NaN 7.682 0.050 -168.2 52.2 686.54 130 66.9 7.732 0.050 -121.4 46.8 563.10 138 66.7 7.782 0.050 -101.2 20.2 418.14 142 66.5 7.832 0.050 -90.3 10.9 299.30 145 66.4 7.899 0.067 -79.1 11.2 206.06 148 66.3 7.962 0.063 -72.0 7.1 NaN 150 66.2 8.065 0.103 -61.8 10.2 NaN 153 66.2 8.158 0.093 -54.9 6.9 NaN 155 66.1 8.300 0.142 -46.8 8.1 NaN 157 66.0 8.450 0.150 -40.5 6.3 NaN 159 65.9

Comments

• The saponification value indicates how much KOH in [mg] is used to saponify 1 g of oil or fat. • According to the Swiss Food Manual (Schweizerisches Lebensmittelbuch) one adds 25 mL KOH in

ethanol (0.5 mol/L) to 2 g of oil or fat, boils for 30 min and performs a back titration with HCl (0.5 mol/L).

• The determination of the saponification value is done by back titration. Therefore, the capacity of the solution without sample (back value) has to be determined first.

• The saponification value determination is a tedious titration, because the samples have to be boiled for 30 min. Therefore, an automated procedure is desirable.

• The analysis procedure was automated using the sample change and the mounted adapter (Claisen adapter can also be used) onto the titration head in order to connect the reflux condenser.


Method – Sample and Back determination Sample determination: 001 Title Type General titration Compatible with T50 / T70 / T90 ID SapValue Title Sap Value Author admin Date/Time 6/13/2012 1:39:12 PM Modified at 6/27/2012 5:11:33 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 1.0 g Upper limit 3.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Rondo/Tower A) Type Rondo/Tower A Titration stand Rondo60/1A Lid handling No 004 Dispense (normal) [1] Titrant KOH in Ethanol Concentration 0.5 mol/L Volume 25.0 mL Dosing rate 60.0 mL/min Condition No 005 Pump Auxiliary reagent Ethanol Volume 40.0 mL Condition No 006 Stir Speed 40% Duration 10 s Condition No 007 Auxiliary instrument Control type Out TTL(Single pin) Name DH100 On Mode Fixed time Time 2.0 s Condition No 008 Measure (normal) [1] Sensor Type Temperature Sensor Pt1000 Unit °C Stir Speed 40% Acquisition of measured values Acquisition Set value Mode T > set value Set value 75.0 °C t (max) 600 s Mean value No Condition Condition No 009 Stir Speed 40% Duration 1800 s Condition No 010 Auxiliary instrument Control type Out TTL(Single pin) Name DH100 Off Mode Fixed time Time 1.0 s Condition No

011 Titration (EQP) [1] Titrant Titrant HCl Concentration 0.5 mol/L Sensor Type pH Sensor DG115-SC Unit mV Temperature acquisition Temperature acquisition Yes Temperature sensor Pt1000 Temperature unit °C Stir Speed 30% Predispense Mode None Wait time 0 s Control Control User Titrant addition Dynamic dE (set value) 8 mV dV (min) 0.05 mL dV (max) 0.15 mL Mode Equilibrium controlled dE 1.0 mV dt 1.0 s t (min) 2.0 s t (max) 20.0 s Evaluation and recognition Procedure Standard Threshold 200.0 mV/mL Tendency Positive Ranges 0 Add. EQP criteria None Termination At Vmax 15 At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No 012 Calculation R1 Result Sap Value Result unit mg KOH/g Formula R1 = (B[Back EQP]-Q)*C/m Constant C = M/z M M[Potassium hydroxide] z z[Potassium hydroxide] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 013 Rinse Auxiliary reagent Ethanol Rinse 1 Vol. per cycle 15 Position Current position Drain No Condition No 014 Conditioning Type Fix Interval 1 Position Conditioning beaker Time 60 s Speed 50 % Condition No 015 End of sample


Back determination: 001 Title Type General titration Compatible with T50 / T70 / T90 ID BackSV Title Back Sap Value Author admin Date/Time 6/27/2012 9:29:11 AM Modified at 6/27/2012 4:19:34 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Fixed volume Volume 25.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Rondo/Tower A) Type Rondo/Tower A Titration stand Rondo60/1A Lid handling No 004 Dispense (normal) [1] Titrant KOH in Ethanol Concentration 0.5 mol/L Volume 25.0 mL Dosing rate 60.0 mL/min Condition No 005 Pump Auxiliary reagent Ethanol Volume 40.0 mL Condition No 006 Stir Speed 40% Duration 10 s Condition No 007 Auxiliary instrument Control type Out TTL(Single pin) Name DH100 On Mode Fixed time Time 2.0 s Condition No 008 Measure (normal) [1] Sensor Type Temperature Sensor Pt1000 Unit °C Stir Speed 40% Acquisition of measured values Acquisition Set value Mode T > set value Set value 75.0 °C t (max) 600 s Mean value No Condition Condition No 009 Stir Speed 40% Duration 1800 s Condition No 010 Auxiliary instrument Control type Out TTL(Single pin) Name DH100 Off Mode Fixed time Time 1.0 s Condition No

011 Titration (EQP) [1] Titrant Titrant HCl Concentration 0.5 mol/L Sensor Type pH Sensor DG115-SC Unit mV Temperature acquisition Temperature acquisition Yes Temperature sensor Pt1000 Temperature unit °C Stir Speed 30% Predispense Mode Volume Volume 15 mL Wait time 60 s Control Control User Titrant addition Dynamic dE (set value) 8 mV dV (min) 0.05 mL dV (max) 0.15 mL Mode Equilibrium controlled dE 1.0 mV dt 1.0 s t (min) 2.0 s t (max) 20.0 s Evaluation and recognition Procedure Standard Threshold 200.0 mV/mL Tendency Positive Ranges 0 Add. EQP criteria None Termination At Vmax 30 At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No 012 Calculation R1 Result Consumption Result unit mmol Formula R1 = Q Constant C= 1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 013 Rinse Auxiliary reagent Ethanol Rinse 1 Vol. per cycle 15 Position Current position Drain No Condition No 014 End of sample 015 Blank Name Back EQP Value B = Mean[R1] Unit mmol Limits No Condition No



Peroxide Value of Edible Oils and Fats According to AOAC No. 28.022 Titration Excellence Line: Method for the determination of the peroxide value in oil, fat and margarine by iodometric titration with sodium thiosulphate of released iodine. A combined redox electrode DMi147-SC with pH- and metal ring half-cells is used to monitor the titration.


If possible, work in a fume hood. ‐ Beakers have to be cleaned very well. Fat

residues or metal traces can affect the result. ‐ About 3 g of sample were dissolved in 20 mL of

acetic acid/chloroform (3:2 v/v). The mixture was added by the function DISPENSE.

‐ 1 mL saturated KI solution is added by an additional burette. 127 g KI were dissolved in 100 mL water to obtain the saturated KI solution. The solution has to be kept in the dark.

‐ The reaction takes place and iodine is formed. ‐ 50 mL deionized water are added by the

membrane pump of the sample changer. ‐ Iodine is titrated with sodium thiosulphate. ‐ Impurities of the solvent are taken into account

by a blank value determination. This is performed under the same conditions as the peroxide value determination itself. The value is stored under B[1].

Remarks

1. Exactly 60 seconds were allowed for the generation of iodine, as is requested by the official method (AOAC No. 28.022).

2. Earlier studies, however, had indicated that the generation is not complete yet at this time. 200 to 300 seconds were found to yield the highest results. Longer generation times resulted in low results (secondary reactions between iodine and the oil).

3. The duration of the generation time i.e. the time between 'adding the KI solution' and 'adding the water + starting the titration' is the critical point to achieve repeatable results.

Sample Sunflower oil, 4-5 g Olive oil, 1 g Margarine, 2 g

Compound Peroxide functional group, R-OOH

Chemicals 3:2 v/v acetic acid/chloroform, 20 mL 1 mL saturated KI solution 50 mL deionized water

Titrant Sodium thiosulfate, Na2S2O3

c(Na2S2O3) = 0.01mol/L

Standard Potassium iodate, KIO3

c(KIO3) = 0.01 mol/L

Indication DMi147-SC combined redox electrode (pH glass/metal ring half-cells)

Chemistry R-OOH + 2 I- + 2 H3O+ → R-OH + I2 + 3 H2O I2 + 2 Na2S2O3 →

2 NaI + Na2S4O6

Calculation R = (Q-B[1])*C/m C = 1000, meq/kg B[1]: Solvent blank value, mmol

Waste disposal

The waste contains halogenated organic solvents and has to be disposed accordingly.

Author, Version

Maria-José Schmid, MSG AnaChem, October 2007


Instruments ‐ Titration Excellence T70/T90 ‐ Rondo 20 Sample Changer with PowerShower™ and diaphragm pump ‐ 2 additional dosing units ‐ XS205 Balance

Accessories ‐ 1 x 20 DV1020 and 2 x 10 mL DV1010 Burettes ‐ Glass titration beaker ME-101446 ‐ LabX® titration software

Results Method: DM1471 Peroxide number 10/25/2007 11:27:34 AM Start time: 25.10.2007 1:53:24 PM ___________________________________________________________________________________________ Sample Data Comment / ID Sample size No. 1/5 Olive oil 0.8164 g No. 2/5 Olive oil 0.8523 g No. 3/5 Olive oil 0.815 g No. 4/5 Olive oil 0.8149 g No. 5/5 Olive oil 0.8235 g Results No. Comment / ID Start time Rx Result Unit Name 1/5 Olive oil 10/25/2007 1:53:25 PM R1 = 0.024 mmol Consumption R2 = 25.601 meq/kg Content 2/5 Olive oil 10/25/2007 2:05:29 PM R1 = 0.025 mmol Consumption R2 = 25.795 meq/kg Content 3/5 Olive oil 10/25/2007 2:17:32 PM R1 = 0.024 mmol Consumption R2 = 26.013 meq/kg Content 4/5 Olive oil 10/25/2007 2:29:19 PM R1 = 0.024 mmol Consumption R2 = 25.888 meq/kg Content 5/5 Olive oil 10/25/2007 2:41:10 PM R1 = 0.024 mmol Consumption R2 = 26.074 meq/kg Content SQC/Statistics Rx Name n Mean Value Unit s srel[%] ____________________________________________________________________________________________ R1 Consumption 5 0.024 mmol 0.000 1.848 R2 Content 5 25.874 meq/kg 0.187 0.724 Additional results Sample Size n Mean value Unit s srel[%] ____________________________________________________________________________________________ Sunflower oil 4-5 g 5 0.028 mmol 0.000 1.609 5.583 meq/kg 0.044 0.791 Margarine 2 g 6 0.022 mmol 0.001 4.624 11.759 meq/kg 0.578 4.918 Mais oil 4-5 g 5 0.021 mmol 0.000 2.150 3.980 meq/kg 0.043 1.087

Titration curve

Sample 3/5 25.10.2007 13:53:24 DM1471 25.10.2007 11:27:34


Table of measured values Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C

0 NaN ‐16.7 NaN NaN 0 25

0.057 0.057 ‐8 8.7 NaN 3 25

0.086 0.029 ‐11.3 ‐3.3 NaN 8 25

0.1 0.014 ‐11.2 0.1 NaN 13 25

0.135 0.035 ‐10.9 0.3 NaN 18 25

0.222 0.087 ‐10.4 0.5 5.85 23 25

0.322 0.1 ‐10.1 0.3 4.51 28 25

0.422 0.1 ‐9.6 0.5 4.57 33 25

0.522 0.1 ‐9.1 0.5 4.98 38 25

0.622 0.1 ‐8.6 0.5 5.57 43 25

0.722 0.1 ‐8.1 0.5 6.12 48 25

0.822 0.1 ‐7.3 0.8 6.4 53 25

0.922 0.1 ‐6.7 0.6 6.84 58 25

1.022 0.1 ‐6 0.7 7.31 64 25

1.122 0.1 ‐5.3 0.7 7.76 69 25

1.222 0.1 ‐4.5 0.8 8.08 74 25

1.322 0.1 ‐3.6 0.9 8.42 79 25

1.422 0.1 ‐2.7 0.9 8.92 84 25

1.522 0.1 ‐1.8 0.9 9.72 89 25

1.622 0.1 ‐0.9 0.9 10.58 94 25

1.722 0.1 0.2 1.1 12.06 99 25

1.822 0.1 1.7 1.5 13.44 104 25

1.922 0.1 3.1 1.4 15.57 109 25

2.022 0.1 4.7 1.6 17.35 114 25

2.122 0.1 6.8 2.1 16.96 120 25

2.222 0.1 8.9 2.1 22.42 125 25

2.322 0.1 12.2 3.3 36.29 130 25

2.422 0.1 15.7 3.5 64.9 135 25

2.522 0.1 21.7 6 129.96 142 25

2.622 0.1 35.3 13.6 311.23 158 25

2.642 0.02 42.2 6.9 520.27 169 25

2.648 0.006 46.4 4.2 822.53 180 25

2.654 0.006 50 3.6 1165.65 190 25

2.661 0.007 57.2 7.2 1330.43 202 25

2.666 0.005 66.2 9 1635.55 217 25

2.671 0.005 78.3 12.1 1915.47 232 25

EQP1 2.671216 NaN 78.8 NaN 1916.21 NaN NaN

2.676 0.005 89.8 11.5 1536.17 247 25

2.681 0.005 97.7 7.9 1263.43 262 25

2.686 0.005 104 6.3 1191.38 277 25

2.694 0.008 109.9 5.9 774.71 292 25

2.704 0.01 114.2 4.3 NaN 303 25

2.728 0.024 120.3 6.1 NaN 318 25

2.772 0.044 125.3 5 NaN 330 25

2.872 0.1 130 4.7 NaN 342 25

2.972 0.1 132.5 2.5 NaN 351 25

Sample 3/5 25.10.2007 13:53:24 DM1471 25.10.2007 11:27:34

Comments

• Fats and oils undergo changes during storage due to oxidation with air (oxidative rancidity). The compounds formed react as peroxides. Their content is commonly expressed as the "peroxide value" in milliequivalents peroxidic oxygen per kg of sample.

• Peroxide values higher than 10 to 20 meq O2/kg are commonly interpreted as rancidity.

• Unrefined edible oils have higher peroxide values. They are usually in the range between 5 to 20 meq O2/kg.

• Literature: Association of Analytical Communities, AOAC INTERNATIONAL Method AOAC No. 28.022


Method 001 Title Type General titration Compatible with T70 / T90 ID DM1471 Title Peroxide number Author schmid Date/Time 10/16/2007 12:37:42 pm Modified at 10/25/2007 11:27:34 am Modified by Administrator Protect No SOP None 002 Sample Number of IDs 1 ID 1 Olive oil Entry type Weight Lower limit 0.5 g Upper limit 20 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Rondo/Tower A Titration stand Rondo60/1A Lid handling No 004 Dispense (normal) [1] Titrant AA/Chloroform Concentration 32 Volume 20 mL Dosing rate 60.0 mL/min Condition No 005 Stir Speed 40% Duration 30 s Condition No 006 Dispense (normal) [2] Titrant KI Concentration 63.5 Volume 1 mL Dosing rate 60.0 mL/min Condition No 007 Stir Speed 30 % Duration 30 s Condition No 008 Stir Speed 0 % Duration 60 s Condition No 009 Pump Auxiliary reagent Water Volume 50.0 mL Condition No 010 Titration (EQP) [1] Titrant Titrant Na2S2O3 Concentration 0.01 mol/L Sensor Type mV Sensor DM147 Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode Volume Volume 0.1 mL Wait time 0 s Control Control Cautious Titrant addition Redox Show parameters Yes Titrant addition Dynamic dE (set value) 6.0 mV dV (min) 0.005 mL dV (max) 0.1 mL Meas. val. acquisition Equilibrium controlled dE 0.5 mV

dt 2.0 s t (min) 5.0 s t (max) 0.1 s Evaluation and recognition Procedure Standard Threshold 200 mV/mL Tendency Positive Ranges 0 Add. EQP criteria No Termination At Vmax 20 mL At potential No At slope No After number of recognized EQPs Yes Number of EPQs 1 Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No 011 Calculation R1 Result Consumption Result unit mmol Formula R1=Q Constant C=1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 012 Calculation R2 Result Content Result unit meq/kg Formula R2=(Q-B[1])*C/m Constant C=1000 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 013 Record . . . . 014 Rinse Auxiliary reagent Water Rinse cycles 1 Vol. per cycle [mL] 10 mL Position Actual position Drain No Condition No 015 Conditioning Type Fix Interval 1 Position According to interval Time 60 s Speed 30% Condition No 016 Rinse Auxiliary reagent Water Rinse cycles 1 Vol. per cycle [mL] 10 mL Position Actual position Drain No Condition No 017 Conditioning Type Fix Interval 1 Position Conditioning beaker Time 10 s Speed 30 % Condition No 018 End of sample 019 Park Titration stand Rondo60/1A Position Conditioning beaker Condition No


METTLER TOLEDO Application M454-2012 Automatic Nitrogen Determination According to Kjeldahl (TTL-IO)

Method template for the determination of nitrogen according to Kjeldahl after digestion using e.g. a Büchi KjelFlex K-360 digestor connected to a Titration Excellence or G20 Compact Titrator via TTL-IO interface.


If possible, work in a fume hood. ‐ Ensure accurate cleaning of electrode is

sufficient after each titration.

This method template shows how to connect the titrator to the Kjeldahl digesting unit. For a detailed procedure of the whole analysis, check the standard operating procedure of customer.

Remarks

The Kjeldahl nitrogen analysis is the standard method for the quantitative determination of organic-bound nitrogen. This technique is the standard procedure for protein determination in food. The analysis is based on three steps:

1. Digestion in sulfuric acid: ‐ The sample is strongly heated in a Kjeldahl

digestion flask containing 98% sulfuric acid, during 2-3 hours.

‐ Nitrogen is released from organic material and is present in the digested solution as ammonium sulfate.

2. Ammonia distillation: ‐ To determine the nitrogen content in the

digested solution, 30% sodium hydroxide solution is added.

‐ Ammonia is generated and collected with hot water steam into a boric acid solution.

‐ In this solution, nitrogen is present as ammonium tetrahydroborate, NH4B(OH)4.

3. Titration:

‐ Ammonium tetrahydroborate ist titrated with sulfuric acid (standard), or it can also be titrated with hydrochloric acid.

Literature:

Swiss Food Manual, Chap. 4.4, Chap. 22-3.1, 4.1, 4.2 http://www.slmb.bag.admin.ch/slmb/index.html

Sample Acidic digested solution of edible samples

Compound After Kjeldahl distillation: Ammonium tetrahydroborate, (NH4)B(OH)4

M=32.88, z=1

Chemicals Digestion: 15-20 mL 98% sulfuric acid, H2SO4

Catalyst – if indicated Distillation: 50 mL deionized water 60-80 mL 30% NaOH 50 mL 1.5% boric acid, H3BO3

Titrant Sulfuric acid, H2SO4 c(1/2 H2SO4) = 0.1 M

Standard TRIS (THAM), 0.05…0.1 g / 50 mL H2O

Indication DGi111-SC or DG115-SC pH combined glass electrode

Chemistry Digestion with H2SO4 (NH4)2SO4 + 2 NaOH → 2 NH3 + Na2SO4 + 2 H2O NH3-Distillation in H3BO3-solution: H3BO3 + H2O → B(OH)4

- + H+

NH3 + B(OH)4- + H+

→ NH4B(OH)4 Titration: 2 NH4B(OH)4 + H2SO4 → (NH4)2SO4 + B(OH)4

- + 2 H+

Calculation R1 = VEQ

Waste disposal

Neutralize before final disposal

Author, Version

Cosimo De Caro MSG AnaChem, June 2012

http://www.slmb.bag.admin.ch/slmb/index.html


Instruments ‐ Titration Excellence T50/T70/T90 or G20 Compact Titrator ‐ 1 x DV1010 glass burette ‐ 100 cm LEMO-SC PnP electrode cable ME-89602 ‐ 100 cm dispensing tube ME-25961

Accessories ‐ Kjeldahl Digestor Büchi Kjelflex K-360 (see: www.buchi.ch) ‐ Büchi RS232 connecting cable No. 43616 (Mini-DIN 6 Pole - D-Sub 9 Pole) ‐ XS205 Balance

Connecting the BUCHI KjelFlex K-360 to Titration Excellence/G20 via TTL/IO

• BUCHI KjelFlex K-360

‐ Use one of the four K-360 configurations which include a titration set (vessel, holder, overhead stirrer).

‐ To connect a K-360 to Titration Excellence or G20 Compact Titrator the BUCHI RS232-cable 43616 is required (Mini-DIN 6 Pole - D-Sub 9 Pole).

• Titration Excellence The distance between titration stand of the KjelFlex K-360 and the Excellence titrator requires a 100 cm electrode cable 89602 and a 100 cm dispensing tube 25961.

• Connecting the TTL-IO cable

‐ At the K-360: K-360: Titration Excellence: the TTL-IO cable is connected to the TTL-IO interface “Titrator”.

‐ At the titrator: it is connected to a COM port at the main or at the sensor board (analog as well as conductivity board).

• K-360 Settings

‐ Configuration → go to titrator → press Enter → go to titrator present → set 1

‐

• Titration Excellence – G20 Compact Titrator Settings

‐ Setup → Hardware → Auxiliary instruments → Parameters

1. Define KJELDAHL TTL IN 2. Define KJELDAHL TTL OUT


Comments

Note:

• Only the titrant consumption is transferred as a result to the K-360.

• Any other result such as mg or mmol Nitrogen per g of sample defined in further calculation method functions is displayed in the result section or is printed if a printer is connected to the titrator.

• If a printer is connected to the K-360 both the titrant consumption and the distillation parameters may be printed after each sample. This requires the following setup at the K-360:

o Configuration → Titrator → Print Data: Yes

• For connection using the serial RS232 interface, see Application No. 449.

Start of the titrator method

• Define a shortcut on the Terminal homepage.

• Start the method.

• The signal is sent after the distillation has been finished at the K-360.

• Then the EP titration is carried out and the result (VEQ) is transferred to the K-360.

• The result transfer triggers the automatic aspiration of the titrated solution into the waste container at the K-360.

Reference

Büchi: http://www.buchi.ch/

http://www.buchi.ch/


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID M454 Title Nitrogen Kjeldahl TTL Author METTLER TOLEDO Date/Time 08/02/2006 03:00:00 pm Modified at 08/02/2006 03:00:00 pm Modified by METTLER TOLEDO Protect No SOP None 002 Sample Number of IDs 1 ID 1 Ammonium Entry type Fixed volume Volume 1.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Auto stand) Type Auto stand Titration stand Auto stand 1 004 Auxiliary instrument Control type Input TTL (Single pin) Name KJELDAHL TTL IN Input signal Falling Max. time 1000000 s Condition No 005 Stir Speed 30% Duration 10 s Condition No 006 Titration (EP) [1] Titrant Titrant ½ H2SO4 Concentration 0.1 mol/L Sensor Type pH Sensor DG111-SC Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control End point type Absolute Tendency None End point value 4.6 pH Control band 2.0 pH Dosing rate (max) 10 mL/min Dosing rate (min) 10 µL/min Termination At EP Yes Termination delay 0 s At Vmax 10 mL Max. time ∞ s Accompanying stating Accompanying stating No Condition Condition No 007 Calculation R1 Result Consumption Result unit mL Formula R1=VEQ Constant C=1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No

008 Calculation R2 Result Content Result unit mg/L Formula R2=Q*C/m Constant C=M/1000*z M M[Nitrogen] z z[Nitrogen] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 009 Auxiliary instrument Control type Out TTL (Single pin) Name KJELDAHL TTL OUT Mode Fixed time Time 1.0 s Condition No 010 End of sample Note

Only the titrant consumption is transferred to the K-360.



Calcium Content in Dairy Products by Back-Titration using a Cu-ISE The calcium content in dairy products such as milk has been determined by complexometric titration of excess Na2-EDTA using a combination Cupric ISE, and Cu(NH3)2-EDTA as indicator.

Preparation and Procedures Sample: - Add the sample to the titration beaker - Add 100 µL 0.1 M Cu(NH3 )2 -EDTA solution - Ammonia solution is dispensed by a burette. - Excess EDTA is added by a second burette.

Cu(II)-Combination ISE: - Fill the Cu-ISE shaft and the electrode tip with the

electrolyte D (P/N 51344753). - Shake the Cu-ISE 2-3 times to avoid the presence of

air bubbles into the electrode tip. - Hold electrode body in the hand, and use thumb to

push down the electrode cap to allow a few drops of electrolyte to drain out.

- Rinse outside with deionized water. - Condition it in deionized water for 20-30 minutes. - After each sample, the electrode is rinsed and

conditioned in deionized water in the conditioning beaker (60 s).

Cu –Indicator solution: - Add 0.624 g CuSO4 in a 25 mL volumetric flask. - Fill with 0.1 mol/L EDTA, add some drops 33% NH3.

Remarks

- All samples used for this application were analyzed directly without pretreatment.

- Dairy products with cacao lead to higher values as its ingredients are also reacting. Thus, a digestion of those dairy products at 250-300°C with 50 mL of 37% HCl (reflux condensing unit) for 2-3 hour is requested. The sample was neutralised with 25 or 33% NH3 solution, and diluted to e.g. 500 mL with deion. water.

- Ammonia solution must be added just before starting titration to avoid evaporation and precipitation of copper hydroxide in alkaline solution.

- 12% ammonia solution NH4OH: o Add 500 mL 25% NH4OH solution to a 1 L flask. o Fill up to 1 L with deionized water.

- For better precision it is of advantage to weigh the dairy samples instead of using a volumetric pipette with a plastic tip.

- Optimal burette size: 20 mL for ammonia, 10 mL for EDTA and ZnSO4.

Literature: - Titration application M269 (version 2004), C. De Caro. - Tore Fossum, "Calcium analysis using a copper sensitive

electrode", USERCOM 9, ME-51 724 376.

Sample Various samples: 1) 5 g 3.5% fat milk, 2) 5 g yoghurt drink with

Stanolester (Strawberry taste) 3) 5 g yoghurt (Strawberry)

Compound Calcium, Ca; M(Ca) = 40.08, z = 1

Chemicals 50 mL ammonia sol., NH4OH, c(NH4OH) = 12%

Titrant - Zinc sulfate, ZnSO4, c(ZnSO4)=0.03 mol/L

- Di-Natrium-EDTA, c(Na2H2EDTA)=0.03 mol/L

Standard - For EDTA: CaCl2

- For ZnSO4: EDTA

Indication perfectION™ Combination Cupric Ion Selective Electrode

Chemistry Ca2+ + Na2H2EDTA → CaEDTA2- + 2 Na+ + 2 H+ (Same reaction with Zn2+ and Cu2+ instead of Ca2+)

Calculation R1 = (QENDDi[2]-QEQ)*C/(m/d) C = M*100/z C = 4008.00 QENDDi [2] = automatic fixed dosing of

EDTA M = molar mass of Ca z = equivalent no. Ca (z=1) m = sample size d = density sample (appr. 1)

Waste disposal

Special waste (heavy metal solutions). Waste contains ammonia. Neutralize before final disposal when collected with Ag or Hg waste.

Author, Version

Christoph Jansen LAS AnaChem, August 2010


Instruments - Titration Excellence T50 / T70 / T90 - 2 additional burette drives DV90 - XP205 balance

Accessories - Titration beaker ME-101974 - 1 x 20 mL DV1020 burette, 2 x 10 mL DV1010 burettes - LabX titration pro software

Results Milk 3.5% No. Comments/ID Start time Rx Result Unit Name

1/5 Milk 3.5% 19.08.2010 11:25:11 R1 = 137.621 mg/100mL Content 2/5 Milk 3.5% 19.08.2010 11:34:53 R1 = 135.701 mg/100mL Content 3/5 Milk 3.5% 19.08.2011 11:44:39 R1 = 138.089 mg/100mL Content 4/5 Milk 3.5% 19.08.2011 11:54:25 R1 = 137.928 mg/100mL Content 5/5 Milk 3.5% 19.08.2011 12:04:22 R1 = 137.102 mg/100mL Content Statistics Rx Name n Mean value Unit s srel[%]

R1 Content 5 137.288 mg/100mL 0.963750 0.702

Yoghurt Statistics Rx Name n Mean value Unit s srel[%]

R1 Yoghurt 3 122.729 mg/100mL 5.645813 4.600

Yoghurt drink Statistics Rx Name n Mean value Unit s srel[%]

R1 Yoghurt drink 3 125.943 mg/100mL 1.232921 0.979

Titration curve

Milk 3.5% sample 1/5 13.08.2010 11:12:27



Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C 0.0000 NaN -516.6 NaN NaN 0 25.0 0.5715 0.5715 -515.1 1.5 NaN 6 25.0 0.8570 0.2855 -514.2 0.9 NaN 14 25.0 1.0000 0.1430 -513.6 0.6 NaN 22 25.0 1.1500 0.1500 -513.0 0.6 NaN 30 25.0 1.3000 0.1500 -512.4 0.6 4.52 38 25.0 1.4500 0.1500 -511.7 0.7 4.80 46 25.0 1.6000 0.1500 -510.9 0.8 5.03 54 25.0 1.7500 0.1500 -510.1 0.8 4.83 62 25.0 1.9000 0.1500 -509.1 1 -1.70 70 25.0 2.0500 0.1500 -507.8 1.3 4.71 78 25.0 2.2000 0.1500 -506.2 1.6 20.37 87 25.0 2.3500 0.1500 -503.6 2.6 51.67 95 25.0 2.5000 0.1500 -497.5 6.1 86.15 103 25.0 EQP1 2.642017 NaN -471.0 NaN 109.8 NaN NaN 2.6500 0.1500 -469.5 28 100.26 112 25.0 2.6620 0.0120 -467.6 1.9 108.81 120 25.0 2.6920 0.0300 -463.8 3.8 92.69 128 25.0 2.7660 0.0740 -457.7 6.1 73.36 136 25.0 2.9160 0.1500 -450.5 7.2 43.83 144 25.0 3.0660 0.1500 -446.6 3.9 25.70 152 25.0 3.2160 0.1500 -443.7 2.9 NaN 160 25.0 3.3660 0.1500 -441.6 2.1 NaN 168 25.0 3.5160 0.1500 -439.9 1.7 NaN 177 25.0 3.6660 0.1500 -438.8 1.1 NaN 185 25.0 3.8160 0.1500 -437.6 1.2 NaN 193 25.0

Milk 3.5% sample 1/5 13.08.2010 11:12:27

Comments - Typical Ca content:

In the literature the Calcium content in milk or yoghurt is 100 – 150 mg/100 mL. Values for cheese are much higher.

- Duration per determination: Approx. 8-9 min per determination if all burettes are 10 mL size. This time can be shorter if a 20 mL burette is used for the dispensing of ammonia solution.

- Waste disposal: Please collect the waste and dispose accordingly. Ammonia with Ag or Hg waste may explode under certain conditions! Thus it is recommended to neutralize after determination. This can be achieved with another dosing unit and burette with concentrated acid (e.g. nitric acid) and a pH electrode.

- Cacao content in In dairy samples with cacao the measurement of Ca2+ is influenced by the amount of cacao. In our test cacao powder was added to milk samples (see figure below). The calcium result increased as follows:

Ca2+ in Ca2+ in Cacao pure milk cacao drink content [mg/100 mL] [mg/100 mL]

137 142 1.6% 137 151 3.2% 137 151 3.6%


Method 001 Title Type General titration Compatible with T50 / T70 / T90 Method ID m269Ca Title Det. of Ca/Milk with Cu ISE Author jansen Date/Time 12.08.2010 15:35:17 Modified on 13.08.2010 12:13:13 Modified by jansen Protect No SOP None 002 Sample Number of IDs 1 ID 1 Milk Entry type Weight Lower limit [g] 3.0 Upper limit [g] 7.0 Density [g/mL] 1.0 Correction factor 1.0 Temperature [°C] 25.0 Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Dispense (normal)[1] Titrant NH3 Concentration 12 Volume [mL] 50 Dosing rate [mL/min] 60.0 Condition No 005 Dispense (normal)[2] Titrant EDTA Concentration [mol/L] 0.03 Volume [mL] 8.0 Dosing rate [mL/min] 60.0 Condition No 006 Stir Speed [%] 40 Duration [s] 60 Condition No 007 Titration (EQP)[1] Titrant Titrant ZnSO4 Concentration [mol/L] 0.03 Sensor Type ISE Sensor Copper ISE Unit mV Ion charge 2 Temperature acquisition Temperature measurement No Stir Speed [%] 30 Predispense Mode Volume Volume [mL] 1 Wait time [s] 0 Control Control Cautious Mode Precipitation Show parameters No Evaluation and recognition Procedure Standard Threshold [mV/mL] 50 Tendency None Ranges 0 Add. EQP criteria No Termination At Vmax [mL] 10.0 At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No

008 Calculation R1 Result Content Result unit mg/100mL Formula R1=(QENDDi[2]-QEQ)*C/(m/d) Constant C= M*100/z M M[Calcium] z z[Calcium] Decimal places 3 Result limits No Record statistics Yes Extra statistical functions No Send to buffer No Condition No 009 End of sample



Calibration of a DX239-K+ Potassium Ion Selective Electrode Method for the adjustment (calibration) of the DX239-K+ potassium ion selective electrode.

Preparation and Procedures CAUTION ‐ Use safety goggles, a lab coat and wear gloves. ‐ Ensure accurate cleaning of electrode is

sufficient after each measurement. 1. Potassium standard solutions are prepared by

dissolving potassium chloride into few deionized water in a volumetric flask and subsequently filled up.

2. The potassium standard solutions are defined as a list of standards "Potassium ppm".

3. Three titration beakers are filled with 40 mL of each potassium standard solutions i.e. 1, 10 and 100 ppm.

4. 40 mL ISA solution are added to each beaker. 5. Place the beakers on the Rondolino sample rack

and start the method. 6. After measurement of each solution the

electrode is cleaned by conditioning it during 30 s in deionized water before starting the next sample (Rondolino mode: Pos. 4).

Remarks

‐ The calibration data are automatically stored in the setup data of the titrator. They are assigned to the sensor used in the method and are only valid for this sensor.

‐ If the sensor is used at a different temperature at

a later time, the titrator corrects the slope of the sensor according to the Nernst equation by manual entry or temperature measurement with a T-sensor.

‐ More details can be found in "Fundamentals of

Titration"(ME-704153) and in the T50/T70/T90 operating instructions.

Sample 40 mL potassium standard solutions 1.17 - 11.7 - 117 ppm Potassium chloride, KCl, M=58.10

Compound Potassium, K+ M = 39.10 , z = 1

Chemicals 40 mL ISA (0.05 M MgSO4)

Titrant --

Standard --

Indication DX239-K+ ISE + DX200 Reference electrode (Bridge electrolyte: 2 M MgSO4)

Chemistry --

Calculation R1 = E; mV Potential measurement of the standard solutions

Waste disposal

--

Author, Version

Maria-José Schmid, MSG AnaChem, June 2007


Instruments ‐ Titration Excellence T50/T70T90, G20 Compact Titrator (with minor changes) ‐ XS205 Balance

Accessories ‐ Rondolino Sample Changer ‐ Titration beaker ME-101974

Results METTLER TOLEDO T90 * Version 1.1.1 * Serial Nr 5127350471 * Titrator ID Excellence Titrator _____________________________________________________________________________________________________ Method ID MJ2 Sample series ID -- Date / Time 06/14/2007 01:57:01 pm User Name Administrator _____________________________________________________________________________________________________ Raw results Sample 1/3 005 Measure (normal) [1] tMe 00:55 min ESTMe -104.5 mV E -103.9 mV Sample 2/3 005 Measure (normal) [1] tMe 00:55 min ESTMe -52.3 mV E -52.2 mV Sample 3/3 005 Measure (normal) [1] tMe 00:57 min ESTMe 4.8 mV E 4.8 mV Raw results 008 Calibration Calib. temperature 25.0 °C Number of segments 2 Slope 1 (TCalib) -57 mV/pM Zero point 1 -1.984 mV/pM Seg. limit 1,2 11.700 ppm Slope 2 (TCalib) -51.70 mV/pM Zero point 2 -2.078 pM

Titration curve


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID MJ41 Title Calibration K electrode Author Administrator Date/Time 06/12/2007 01:13:56 pm Modified at 06/14/2007 11:48:03 am Modified by Administrator Protect No SOP None 002 Sample (Calib) Sensor type ISE Sensor DX239-K+ Ion charge 1 Unit ppm List of standards Potassium ppm Calibration Segmented Number of standards 3 Standard 1 1.17 Standard 2 11.7 Standard 3 117 Temperature 25.0°C 003 Titration stand (Rondolino TTL) Type Rondolino TTL Titration stand Rondolino TTL 1 004 Stir Speed 30% Duration 180 s Condition No 005 Measure (normal) [1] Sensor Type ISE Sensor DX239-K+ Unit mV Ion charge 1 Temperature acquisition Temperature acquisition No Stir Speed 30 % Acquisition of measured values Acquisition Equilibrium controlled dE 0.5 mV dt 1 s t(min) 10 s t(max) 30 s Mean value Yes No of measured values 5 dt 1 s Condition Condition No 006 Record Summary No Results No Raw results Per sample Table of meas. values No Sample data Per sample Resource data No E - V No dE/dV - V No log dE/dV - V No d2E/dV2 - V No E - t No V - t No dV/dt - t No T - t No E - V & dE/dV - V No V - t & dV/dt - t No Method No Series data No Condition No 007 End of sample 008 Calibration Sensor DX239-K+ Limits No Condition No

009 Record Summary Yes Results No Raw results Yes Resource data No Calibration curve Yes Method No Series data No


METTLER TOLEDO Application M444-2007 Potassium Determination in Water by Potentiometric Direct Measurement

The potassium content in water samples is determined by direct measurement using a DX239-K+ potassium ion selective electrode.

Preparation and Procedures CAUTION ‐ Use safety goggles, a lab coat and wear gloves. ‐ Ensure accurate cleaning of electrode is

sufficient after each measurement. 1. The DX239-K+ electrode is previously adjusted

(calibrated) using potassium chloride standard solutions (see Application M443). The potassium standard solutions are defined as a list of standards "Potassium ppm".

2. The titration beakers are filled with 40 mL water sample.

3. 40 mL ISA solution are added to each beaker. 4. Place the beakers on the Rondolino sample rack

and start the method. 5. After measurement of each solution the

electrode is cleaned by conditioning it during 30 s in deionized water before starting the next sample (Rondolino mode: Pos. 4).

Remarks

‐ To improve accuracy and reproducibility of the measurement, perfom the electrode calibration and sample measurement at the same temperature and stirring speed.

‐ The titrator corrects the slope of the sensor according to the Nernst equation by manual entry or temperature measurement with a T-sensor.

Additional ISE-Applications:

‐ METTLER TOLEDO Applications Brochure Nr. 6 "Direct Measurement with ISE", ME-51724646

‐ METTLER TOLEDO Applications Brochure Nr. 7 "Incremental Techniques with ISE, ME-51724648

‐ METTLER TOLEDO Applications Brochure Nr. 12 "30 Selected Applications", ME-51724765

‐ METTLER TOLEDO Applications Brochure Nr. 13 "Nitrogen Determination by Kjeldahl Digestion", ME-51724769

Sample 40 mL water samples (e.g. mineral water)

Compound Potassium, K+ M = 39.10 , z = 1

Chemicals 40 mL ISA (0.05 M MgSO4)

Titrant --

Standard --

Indication DX239-K+ ISE + DX200 Reference electrode (Bridge electrolyte: 2 M MgSO4)

Chemistry --

Calculation R1 = E; mV Potential measurement of the standard solutions

Waste disposal

--

Author, Version

Maria-José Schmid, MSG AnaChem, June 2007


Instruments ‐ Titration Excellence T50/T70T90, G20 Compact Titrator (with minor changes) ‐ XS205 Balance

Accessories ‐ Rondolino Sample Changer ‐ Titration beaker ME-101974

Results METTLER TOLEDO T90 * Version 1.1.1 * Serial Nr 5127350471 * Titrator ID Excellence Titrator _____________________________________________________________________________________________________ Method ID MJ5 Sample series ID Mineral water 1 Date / Time 06/14/2007 12:46:34 pm User Name Administrator _____________________________________________________________________________________________________ Statistics R1(Potential) Number of samples 5 Mean value 1.208 ppm s 0.016 ppm srel 1.343 % Expected content: 1.2 ppm ---------------------------------------------------------------------------------- Mineral water 2 (expected content: 2.5 ppm) Statistics R1(Potential) Number of samples 5 Mean value 1.275 ppm s 0.041 ppm srel 3.182 % ---------------------------------------------------------------------------------- Mineral water 3 (expected content: unknown) Statistics R1(Potential) Number of samples 5 Mean value 0.810 ppm s 0.009 ppm srel 1.166 %

Curve

--


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID MJ5 Title K in water Author Administrator Date/Time 06/07/2007 12:35:04 pm Modified at 06/14/2007 12:46:34 am Modified by Administrator Protect No SOP None 002 Sample Number of IDs 1 ID 1 Mineral water 1 Entry type Fixed volume Volume 40 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Rondolino TTL) Type Rondolino TTL Titration stand Rondolino TTL 1 004 Stir Speed 30% Duration 180 s Condition No 005 Measure (normal) [1] Sensor Type ISE Sensor DX239-K+ Unit ppm Ion charge 1 Temperature acquisition Temperature acquisition No Stir Speed 30 % Acquisition of measured values Acquisition Equilibrium controlled dE 0.5 mV dt 1 s t(min) 10 s t(max) 30 s Mean value No Condition Condition No 006 Calculation R1 Result Content Result unit ppm Formula R1=E Constant C= 1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra stat. function No Condition No 007 Record Summary No Results No Raw results Per sample Table of meas. values No Sample data Per sample Resource data No E - V No dE/dV - V No log dE/dV - V No d2E/dV2 - V No E - t No V - t No dV/dt - t No T - t No E - V & dE/dV - V No V - t & dV/dt - t No Method No Series data No Condition No 008 End of sample



Citrate Content Determination Using a Cu-Ion Selective Electrode Determination of citrate content in mineral water drinks by potentiometric titration with copper sulphate and a copper ion selective electrode (Cu-ISE) as indicating electrode.


Preparation of Borax buffer pH 9.0:

- Prepare 1 L 0.025 M Na2B4O7*10H2O (borax)

- The pH value is adjusted to 9.0 with 0.1 M HCl.

Sample preparation:

- First, the mineral water drink is degassed by means of an ultrasonic bath during 5 min or more (alternative: apply a vacuum).

- Second, the sample is passed through a cation exchange resin in the following way:

o Fill a glass tube with approx. 20 g strongly acidic cation exchange resin (Dowex 50 WX8) and rinse with deionized water, e.g. 10 mL.

o Mineral water drink is run through the column containing the exchange resin, and collected into a beaker.

o The column is rinse with 10 mL dist. water.

- Transfer 25 mL of sample into a titration beaker.

- Methanol, borate buffer and NaOH solutions are added by additional dosing units.

Remarks

- The method can be easily modified for automated operation. Select the sample changer in the function "Titration stand".

- The parameters have been optimized for the above sample. It may be necessary to slightly adapt the method to your specific sample.

- The electrode is conditioned in deionized water after each sample. If necessary, gently polish the Cu-ISE solid state membrane.

- Maintain the sample solution at pH 9.4 with 1 mol/L sodium hydroxide.

- Borate buffer is used to avoid interferences.

- Copper(II) ions Cu2+ forms a 1:1 stable complex with citrate anions. The free copper(II) concentration is monitored with the combined Cu-ISE.

Sample Mineral water drinks, containing citrate or citric acid, 25 mL

Compound Citric acid, C3H5O(COOH)3 M = 192.12 g/mol, z = 1 (1:1 soluble complex in solution)

Chemicals - Borax Buffer (pH 9) - Methanol - Strongly acidic cation exchange

resin (Dowex 50 WX8) - Sodium hydroxide, 1 M NaOH - Hydrochloric acid, 0.1 M HCl - Deionized water

Titrant Copper sulphate, CuSO4 c(CuSO4) = 0.05 mol/L

Standard Sodium thiosulphate, Na2S2O3

Indication - perfectION™ combination Cu-ISE - DGi115-SC pH combination sensor

Chemistry Simplified scheme:

Cu2+ + C3H5O(COO)33- →

Cu(C3H5O(COO)3-

Calculation R1= QEQ*C/m C = M/z (g/L) QEQ= Titrant consumption (mmol) M = Molar mass of citric acid m = Sample size in mL z = Equivalent number

Waste disposal

Comply with Federal, State and local regulations. Sweep up crystals, powder or insoluble copper carbonate and dispose as special waste.

Author, Version

Vineesh Pallath, IMSG Anachem, Oct 2010 Revised: Claudia Schreiner/C. De Caro MSG AnaChem, February 2011


Instruments - Titration Excellence T50/T70/T90 - 3 additional Dosing Units - Rondo 20 Sample Changer with PowerShower™ - LabX titration pro software Accessories - 2 x DV1010 10 mL burettes (CuSO4, NaOH) - 2 x DV1020 20 mL burettes (Borate buffer pH 9, methanol) - SP 250 Peristaltic pump - PP titration beakers ME-101974

Results All results Method-ID VP0076dispNAOH Sample 7UP with extraction (1/6) R1 Content 3.078 g/L R2 pH 9.34 Sample 7UP with extraction (2/6) R1 Content 3.076 g/L R2 pH 9.39 Sample 7UP with extraction (3/6) R1 Content 3.086 g/L R2 pH 9.41 Sample 7UP with extraction (4/6) R1 Content 3.057 g/L R2 pH 9.43 Sample 7UP with extraction (5/6) R1 Content 3.060 g/L R2 pH 9.46 Sample 7UP with extraction (6/6) R1 Content 3.053 g/L R2 pH 9.51 Statistics Method-ID VP0076dispNAOH R1 Samples 6 Mean Mean Content 3.068 g/L s 0.013 g/L srel 0.437 %

Titration curve

Sample 1/6 29.10.2010 VP0076dispNaOH


Table of measured values Volume Increment Signal 1st deriv. Time Temperature mL mL mV mV/mL s °C 0.0000 -204.1 NaN 0 25.0 3.4285 3.4285 -198.9 NaN 9 25.0 5.1430 1.7145 -190.8 NaN 20 25.0 6.0000 0.8570 -176.7 NaN 37 25.0 6.2000 0.2000 -170.9 NaN 58 25.0 6.2945 0.0945 -168.2 20.54 68 25.0 6.4395 0.1450 -164.8 22.27 78 25.0 6.6395 0.2000 -160.9 22.91 88 25.0 6.8395 0.2000 -156.7 20.40 98 25.0 7.0265 0.1870 -152.7 20.83 108 25.0 7.2045 0.1780 -148.8 21.58 118 25.0 7.3880 0.1835 -144.8 22.68 128 25.0 7.5705 0.1825 -140.7 24.01 138 25.0 7.7360 0.1655 -136.5 26.14 148 25.0 7.8850 0.1490 -132.5 28.99 158 25.0 8.0225 0.1375 -128.3 32.60 168 25.0 8.1345 0.1120 -124.5 36.09 179 25.0 8.2410 0.1065 -120.4 39.76 189 25.0 8.3370 0.0960 -116.4 42.95 199 25.0

EQP1 8.364708 NaN -115.1 43.12 NaN NaN 8.4200 0.083 -112.5 42.80 209 25.0 8.5010 0.081 -108.8 38.84 219 25.0 8.5850 0.084 -105.3 34.08 229 25.0 8.6950 0.1100 -101.6 28.82 239 25.0 8.8450 0.1500 -98.1 22.12 249 25.0 9.0450 0.2000 -94.7 15.34 259 25.0 9.2450 0.2000 -92.1 NaN 269 25.0 9.4450 0.2000 -90.1 NaN 279 25.0 9.6450 0.2000 -88.4 NaN 289 25.0 9.8450 0.2000 -86.8 NaN 299 25.0 10.0000 0.1550 -85.8 NaN 310 25.0

Sample 1/6 29.10.2010 VP0076dispNaOH

Comments

• Citric acid:

• Literature:

- Terrence B. Field, Janet L. McCourt, W. A. E. McBryde, “Composition and Stability of Iron and Copper Citrate Complexes in Aqueous Solution”, Can. J. Chem. Vol. 52, 1974, pp. 3119-3124.

http://upload.wikimedia.org/wikipedia/commons/c/c5/Zitronens%C3%A4ure_-_Citric_acid.svg


Method 001 Title Type General titration Compatible with T50 / T70 / T90 ID VP0076dispNaOH Title Citrate Content Author pallath Date/Time 28.10.2010 16:37:26 Modified at 29.10.2010 09:02:05 Modified by pallath Protect No SOP None 002 Sample Number of IDs 1 ID 1 7UP with extraction Entry type Fixed volume Volume[mL] 25 Density[g/mL] 1.0 Correction factor 1.0 Temperature[°C] 25.0 003 Titration stand (Manual stand) Type Rondo/Tower A Titration stand Rondo60/1A Lid handling No 004 Dispense (normal) [1] Titrant Methanol Concentration 100 Volume[mL] 25 Dosing rate [mL/min] 60.0 Condition No 005 Dispense (normal) [2] Titrant Borax Buffer 9 Concentration 100 Volume[mL] 25 Dosing rate [mL/min] 60.0 Condition No 006 Dispense (normal) [1] Titrant NaOH Concentration 1 Volume[mL] 2.5 Dosing rate [mL/min] 60.0 Condition No 007 Stir Speed[%] 35 Duration[s] 10 Condition No 008 Measure (normal)[1] Sensor Type pH Sensor DGi115-SC Unit pH Temperature acquisition Temperature Measurement No Stir Speed[%] 30 Acquisition of measured values Acquisition Equilibrium controlled dE[mV] 0.5 dt[s] 1 t(min)[s] 2 t(max)[s] 30 Mean value Yes No of measured values 4 dt[s] 2 Condition Condition No 009 Titration (EQP) [1] Titrant Titrant CuSO4 Concentration [mol/L] 0.05 Sensor Type ISE Sensor Cu ISE Unit mV Ion Charge 2 Temperature acquisition Temperature acquisition No Stir Speed[%] 30 Predispense Mode Volume

Volume[mL] 6 Wait time[s] 10 Control Control User Titrant addition Dynamic dE (set value)[mV] 4 dV (min)[mL] 0.02 dV (max)[mL] 0.2 Mode Equilibrium controlled dE[mV] 0.5 dt[s] 2.0 t (min)[s] 10 t (max)[s] 30 Evaluation and recognition Procedure Standard Threshold[mV/mL] 35 Tendency Positive Ranges 0 Add. EQP criteria No Termination At Vmax[mL] 10 At potential No At slope No After number of recognized EQPs No Combined termination criteria No Accompanying stating Accompanying stating No Condition Condition No 010 Calculation R1 Result Content Result unit g/L Formula R1=QEQ*C/m Constant C= M/z M M[Citrate] z z[Citrate] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 011 Calculation R2 Result pH value Result unit Formula R2=E[1] Constant C= 1 M M[None] z z[None] Decimal places 2 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 012 Rinse Auxiliary reagent Water Rinse cycles 1 Vol.per cycle[mL] 10 Position Current position Drain Yes Drain pump Drain pump 1 Condition No 013 Conditioning Type Fix Interval 1 Position Conditioning beaker Time[s] 60 Speed[%] 30 Condition No 014 End of sample 015 Park Titration stand Rondo60/1A Position Conditioning beaker Condition No

METTLER TOLEDO Page 1 of 6 Titration Application M476A-2011

METTLER TOLEDO Application M476A-2011 Determination of Nitrite Content in Soya Sauce by Back Titration with Fe(II) - FAS The nitrite content in soya sauce and in nitrite standard solution is determined by redox back titration with iron(II) ammonium sulfate (FAS) after addition of a known excess of potassium permanganate solution. The titration is monitored with a combined platinum ring electrode.

Preparation and Procedures CAUTION: • Potassium dichromate is highly toxic! • Heat is developed when dissolving H2SO4 in H2O • Work in a fume hood and use safety goggles,

wear gloves and a lab coat.

Preparation 0.1 mol/L Ammonium ferrous sulfate, FAS: - Weigh 39.2 g FAS in a 1000 mL amber colored

volumetric flask and slowly add 5% sulfuric acid with constant stirring

- Stir to dissolve, then fill up to the mark with deionized water and shake well before transferring to an amber colored bottle.

0.02 mol/L Potassium permanganate, KMnO4: - Add 3.2 g potassium permanganate in 1000 mL

volumetric flask, and add approx. 200 mL water - Stir to dissolve and fill it up to 1000 mL with

deionized water. - Heat the solution for 20-30 minutes.

Sodium nitrite standard solution, NaNO2: - Accurately weigh 0.1 ± 0.0001g sodium nitrite in

100 mL volumetric flask, and add 15-20 mL deionized water. Stir to dissolve, and fill up to the mark with deionized water.

Soya standard solution: - Pipette 2.5 mL soya sauce in 500 mL vol. flask.

Add 200 ml deion. water and shake to mix. Fill up to the mark with deionized water.

Procedures • Blank determination (back value)

- Add 15 mL KMnO4 solution in the beaker - Add 30 mL 25% v/v H2SO4. - Titrate with FAS.

• Nitrite standard sample solution - Pipette 5 mL NaNO2 std solution in the beaker - Add 15 mL KMnO4 solution - Add 30 mL 25% v/v H2SO4 - Titrate with FAS (Note: dilution factor = 20)

• Soya sample solution - Pipette 5 mL soya sample sol. into the beaker - Pipette 5 mL NaNO2 std solution in the beaker - Add 15 mL KMnO4 solution - Add 30 mL 25% v/v H2SO4 - Titrate with FAS (Note: dilution factor = 200).

Sample Soya sauce solution, 5 mL Sodium nitrite, NaNO2, ca. 0.1g

Compound Nitrite ion, NO2-

M = 46.00 g/mol, z = 2

Chemicals Deionized water 5-25% v/v Sulfuric acid, H2SO4 0.02 mol/L KMnO4

Titrant Ammonium ferrous sulfate(II)

FAS, (NH4)2Fe(SO4)2 • 6H2O c(FAS) = 0.1 mol/L M = 392.21 g/mol, z = 1

Standard Potassium dichromate, K2Cr2O7 M = 294.18 g/mol, z = 6

Indication DMi140-SC Combined platinum ring electrode

Chemistry 1. Reaction with excess KMnO4 2MnO4

- + 5NO2- + 6H+ →

2Mn2+ + 5NO3- + 3H2O

2. Back-titration with FAS MnO4

- + 5Fe2+ + 8H+ → Mn2+ + 5Fe3+ + 4H2O

Calculation R1 = (H[Auxvalue]-Q)*C/(m*d) C = M*1000/z H[Auxvalue]=Back value Q = Titrant consumption in mmol M = Molar mass of nitrite m = Sample size in mL z = Equivalent number of nitrite d = Density of nitrite sample

Waste disposal

Special waste / heavy metals (Mn, Cr)

Author, Version

Bhupendra Jain, IMSG Anachem, January 2011 Revised: Th. Hitz / C. De Caro, MSG Anachem, 03.2011/03.2012


Instruments - G20 Compact Titrator Note: This application can be also run with the T50/T70/T90 Titration Excellence

- Rondolino automated titration stand - XP205 Balance

Accessories - LabX light titration software - DV1020 burette 20 mL (MT-51107502) - PP Titration beaker (ME-101974)

Results Blank: Results Method-ID BlankNitrite Sample BlankNitrite (1/3) R1 1.510 mmol Sample BlankNitrite (2/3) R1 1.507 mmol Sample BlankNitrite (3/3) R1 1.502 mmol Blank: Statistics Method-ID BlankNitrite R1 3 Samples 3 Mean 1.506 mmol s 0.004 mmol

srel 0.268% -------------------------------------------------------------------------------------

Nitrite Std sample: Results Method-ID Nitrite Sample Nitrite standard (1/6) R1 576.3432 ppm Sample Nitrite standard (2/6) R1 577.9164 ppm Sample Nitrite standard (3/6) R1 574.2226 ppm Sample Nitrite standard (4/6) R1 569.2868 ppm Sample Nitrite standard (5/6) R1 574.8298 ppm Sample Nitrite standard (6/6) R1 577.7784 ppm Nitrite Std sample: Statistics Method-ID Nitrite R1 6 Samples 6 Mean 575.0629 ppm s 3.2025 ppm

srel 0.557%

Note: The content of the nitrite standard solution is obtained by multiplying the sample result R1 by the dilution factor of 20 (see “Preparation and Procedures”).

------------------------------------------------------------------------------------- Soya sauce: Results (spiked sample) Method-ID Nitrite Sample Soya sauce (1/6) R1 982.6290 ppm Sample Soya sauce (2/6) R1(ppm) 1004.1616 ppm Sample Soya sauce (3/6) R1(ppm) 1002.7218 ppm Sample Soya sauce (4/6) R1(ppm) 996.1116 ppm Sample Soya sauce (5/6) R1(ppm) 1012.9936 ppm Sample Soya sauce 6/6) R1(ppm) 1079.5326 ppm Soya sauce: Statistics (spiked sample) Method-ID Soya sauce R1 6 Samples 6 Mean 1013.0250 ppm s 34.1114 ppm srel 3.367%

Note: - The titration sample has been spiked by adding 5 mL NaNO2 standard solution. - Thus, the correct value for the nitrite content of the titrated sample is obtained by

subtracting the spiked amount R(spike) from result R1. In this way we get the nitrite content of the titrated soya sample R(sample), i.e. R(sample)= R1 – R(spike).

- The content of the soya solution prepared in the 500 ml volumetric flask is obtained by multiplying the nitrite content of the titrated soya sample R(sample) by the dilution factor of 200 (see “Preparation and Procedures”), i.e. R(sample)*200.


Titration curve Back value

Nitrite standard

Soya sauce



Back value determination Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C 0.000 NaN 1353.3 NaN NaN 0 25.0 0.030 0.03 1356.8 3.5 NaN 1 25.0 0.060 0.03 1357.4 0.6 NaN 2 25.0 0.135 0.075 1357.9 0.5 NaN 4 25.0 0.323 0.188 1358.3 0.4 NaN 5 25.0 1.523 0.300 1359.1 0.1 0.45 11 25.0 --- --- --- --- --- --- --- 12.623 0.300 1341.7 -1.6 -6.10 68 25.0 13.823 0.300 1331.7 -2.7 -13.05 74 25.0 14.123 0.300 1326.3 -5.4 54.97 75 25.0 14.423 0.300 1320 -6.3 9.72 77 25.0 14.723 0.300 1306.7 -13.3 -170.87 78 25.0 15.023 0.300 1286.8 -19.9 -560.5 81 25.0 15.270 0.247 1265.3 -21.5 -817.32 84 25.0 EQP1 15.369692 NaN 975.1 NaN -964.68 NaN NaN 15.427 0.157 808.2 -457.1 -766.89 95 25.0 15.457 0.03 725.4 -82.8 -920.89 104 25.0 15.487 0.03 712.9 -12.5 -732.56 105 25.0 15.562 0.075 696.4 -16.5 -590.53 107 25.0 15.718 0.156 675.6 -20.8 -485.64 108 25.0 15.941 0.223 660.2 -15.4 -106.53 110 25.0 16.241 0.300 642.5 -17.7 -52.10 111 25.0 16.541 0.300 361.8 7.0 130.81 377 25.0 16.841 0.300 620.6 -9.4 NaN 114 25.0 17.141 0.300 614.8 -5.8 NaN 116 25.0 17.441 0.300 608.3 -6.5 NaN 117 25.0 17.741 0.300 604.4 -3.9 NaN 119 25.0 18.000 0.259 602.2 -2.2 NaN 120 25.0

Nitrate standard

Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C

0.000 NaN 1334.2 NaN NaN 0 25.0 0.020 0.020 1336.1 1.9 NaN 3 25.0 0.040 0.020 1336.8 0.7 NaN 6 25.0 0.090 0.050 1338.1 1.3 NaN 11 25.0 0.215 0.125 1338.7 0.6 NaN 14 25.0 0.515 0.300 1339.0 0.3 2.74 17 25.0 --- --- --- --- --- --- --- 13.794 0.253 1252.5 -25.2 -111.60 187 25.0 13.823 0.029 1251.6 -0.9 -551.69 191 25 13.895 0.072 1242 -9.6 -1066.50 204 25 13.915 0.02 1238.8 -3.2 -966.17 214 25 13.958 0.043 1232.5 -6.3 -1233.84 229 25 14.016 0.058 1224 -8.5 -2599.10 245 25

EQP1 14.054435 NaN 976.4 NaN -4062.93 NaN NaN 14.071 0.055 869.7 -354.3 -3039.03 265 25 14.091 0.020 788.1 -81.6 -3634.13 285 25 14.111 0.020 744.1 -44 -3007.16 305 25 14.131 0.020 717.0 -27.1 -1993.85 325 25 --- --- --- --- --- --- --- 15.032 0.253 634.6 -8 NaN 391 25 15.332 0.300 626.9 -7.7 NaN 394 25 15.632 0.300 621.0 -5.9 NaN 398 25 15.932 0.300 615.9 -5.1 NaN 401 25 16.000 0.068 614.3 -1.6 NaN 404 25

Soya sauce

Volume Increment Signal Change 1st deriv. Time Temperature mL mL mV mV mV/mL s °C

0.000 NaN 1293.1 NaN NaN 0 25.0 0.020 0.02 1294.3 1.2 3 25.0 0.040 0.02 1294.7 0.4 6 25.0 0.090 0.05 1295.3 0.6 9 25.0 0.215 0.125 1295.8 0.5 12 25.0 0.515 0.3 1296.1 0.3 2.11 15 25.0 0.815 0.3 1296.4 0.3 0.97 18 25.0 --- --- --- --- --- --- --- 11.315 0.300 1283.5 -1.4 -5.81 125 25.0 11.615 0.300 1280.6 -2.9 -8.49 130 25.0 11.915 0.300 1278.3 -2.3 -11.12 135 25.0 12.215 0.300 1274.0 -4.3 -16.96 144 25.0 12.515 0.300 1266.5 -7.5 -73.69 160 25.0 12.815 0.300 1255.1 -11.4 -363.53 180 25.0 12.964 0.149 1248.5 -6.6 -814.9 200 25.0 13.117 0.153 1229.8 -18.7 -1833.50 220 25.0 13.141 0.024 1171.9 -57.9 -2484.67 223 25.0

EQP1 13.155388 NaN 1030.4 NaN -4472.13 NaN NaN 13.161 0.020 975.2 -196.7 -2900.59 244 25.0 13.181 0.020 847.9 -127.3 -2815.13 264 25.0 13.201 0.020 788.8 -59.1 -3940.15 284 25.0 13.221 0.020 751.2 -37.6 -2129.70 304 25.0 13.241 0.020 724.9 -26.3 -1532.91 324 25.0 13.261 0.020 706.1 -18.8 -1091.61 344 25.0 --- --- --- --- --- --- --- 15.825 0.300 597.6 -3.7 NaN 391 25.0 16.000 0.175 595.5 -2.1 NaN 394 25.0


Comments

General remarks:

• The method parameters have been optimized for the above samples. It may be necessary to slightly adapt this method for your specific samples.

• Automation is achieved with a Rondolino sample changer (setting conditioning with deionized water for 30 seconds).

• The sample was spiked with nitrite standard to improve reproducibility.

• The density of the sample has to be measured in order to obtain the mass.

Procedures:

• Titer determination of FAS is performed using potassium dichromate, K2Cr2O7, as a standard:

Cr2O72− + 6 Fe2+ + 14 H+ → 2 Cr3+ + 6 Fe3+ + 7 H2O

• Analysis steps: 1. Titer determination 2. Back value determination:

The back value is automatically stored as B[Blank] in the setup of the instrument. 3. Sample titration:

The back value has to be entered manually in the G20 as H[AuxValue].

Titration:

• Titer determination of FAS is performed using potassium dichromate, K2Cr2O7, as a standard:

Cr2O72− + 6 Fe2+ + 14 H+ → 2 Cr3+ + 6 Fe3+ + 7 H2O

• Principle of back titration of nitrite: 1. Addition of an excess of potassium permanganate solution 2. Reaction of nitrite with permanganate according to:

2 MnO4- + 5 NO2

- + 6 H+ → 2 Mn2+ + 5 NO3- + 3 H2O

3. Remaining permanganate solution is titrated with FAS: MnO4

- + 5 Fe2+ + 8 H+ → Mn2+ + 5 Fe3+ + 4 H2O

A back titration is performed since the oxidation of permanganate ions at room temperature is very slow. By adding a known amount of permanganate solution before titration, the concentration is present in excess. In this way, the reaction rate between permanganate nitrite ions is increased.

Literature:

1. Vogel’s “Textbook of Quantitative Analytical Chemistry”, 5th Edition, Longman, 1989.

2. “Standardization of Titrants – Memory Card Applications Package”, METTLER TOLEDO Titration Applications Brochure No. 18, ME-51724917, 2005.

3. “Standardization of Titrants II”, METTLER TOLEDO Titration Applications Brochure No. 9, ME-51724652, 2004.


Method Blank value determination (Back value) 001 Title Type General titration Compatible with G20 ID BlankNitrite Title BlankNitrite Author LabX-Light Date/Time 1/25/2011 3:42:13 PM Modified at 2/2/2011 10:37:33 AM Modified by LabX-Light Protect No SOP None 002 Sample Number of IDs 1 ID 1 Blank nitrite Entry type Fixed volume Fixed volume 15 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Rondolino TTL) Type Rondolino TTL Titration stand Rondolino TTL1 004 Stir Speed 30% Duration 20 s Condition No 005 Titration (EQP) [1] Titrant Titrant FAS(II) Concentration 0.1 mol/L Sensor Type mV Sensor DM140-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Control Fast Mode Redox Show parameters No Evaluation and recognition Procedure Standard Threshold 200 Tendency None Ranges 0 Add. EQP criteria No Termination At Vmax 18 At potential No At slope No After number of recognized EQPs No Combined termination criteria No 006 Calculation R1 Result type Predefined Calculation type Direct titration Result Consumption Result unit mmol Formula R1=Q Selected EQP 1 Constant C= 1 M M[None] z z[None] Decimal places 3 Result limits No Record Statistics Yes 007 End of sample 008 Blank Name Blank Value B= Mean[R1] Units mmol Limits No 009 Calculation R2 Result type User defined Result Mean Blank EQP Result unit mmol Formula R2=Mean[R1] Constant C= 1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes

Sample titration 001 Title Type General titration Compatible with G20 ID Nitrite Title Nitrite Author LabX-Light Date/Time 1/25/2011 1:54:31 PM Modified at 2/3/2011 4:49:03 PM Modified by LabX-Light Protect No SOP None 002 Sample Number of IDs 1 ID 1 Soya sauce Entry type Fixed volume Fixed volume 5 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Rondolino TTL) Type Rondolino TTL Titration stand Rondolino TTL1 004 Stir Speed 30% Duration 30 s Condition No 005 Titration (EQP) [1] Titrant Titrant FAS(II) Concentration 0.1 mol/L Sensor Type mV Sensor DM140-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Control User Titrant addition Dynamic dE(set value) 8.0 mV dV(min) 0.02 mL dV(max) 0.3 Mode Equilibrium controlled dE 0.5 mV dt 2.0 t(min) 3.0 t(max) 20 Evaluation and recognition Procedure Standard Threshold 200 Tendency None Ranges 0 Add. EQP criteria No Termination At Vmax 16 At potential No At slope No After number of recognized EQPs No Combined termination criteria No 006 Calculation R1 Result type Predefined Calculation type Back titration manual Result Content Result unit ppm Formula R1=(H[AuxValue]-Q)*C/(m*d) Selected EQP 1 Constant C= M*1000/z M M[Nitrite] z z[Nitrite] Decimal places 4 Result limits No Record Statistics Yes 007 End of sample



Determination of Potassium Sorbate (E 202) in Food Products Potassium sorbate (E 202) in margarine and cheese spread is determined by titration with perchloric acid in a non-aqueous solution.


Precautions: - The pH electrode is dipped overnight in

deionized water in order to condition it. This guarantees the rehydration of the sensor.

- Use safety goggles, mask and wear gloves while handling acids.

- Ensure the cleaning of electrode is sufficient after each titration.

Sample titration of potassium sorbate: - Weigh 0.1 g of potassium sorbate, add 40mL of

glacial acetic acid, dissolve and titrate.

Sample titration of margarine: - Weigh about 10.0 g margarine, add 40 mL


Sample titration of cheese spread: - Weigh about 0.7 g cheese spread, add 40 mL


Remarks

• A thermostatable beaker is used to improve dissolution of the highly viscous samples.

• By increasing the stir time the dissolution can be also improved.

• The sample solution is warmed at approximately 40.0 ºC to dissolve and to avoid that samples are sticking on the electrode and the propeller. Thus, a better reproducibility is achieved

• Titer determination: The titer value TITER = 1.00291was determined according to M524. See METTER TOLEDO Application M524, “Titer of HClO4 0.1 mol/L (non aqueous)”, Titration Applications Brochure No. 18, ME-51 724 917 (Dec. 2005).

• Potassium sorbate is mainly used as a food preservative (E 202) to inhibit molds and yeasts in e.g. cheese, baked goods, dried meats, yogurt, wine, soft and fruit drinks. E202 can also be found in many dried fruit products.

Sample Margarine, 10 g Cheese spread, 0.7 g Potassium sorbate, 0.1 g

Compound Potassium sorbate, C6H7KO2 M = 150.22 g/moL z = 1

Chemicals Glacial acetic acid, CH3COOH 40 mL

Titrant Perchloric acid, HClO4 in glacial acetic acid c(HClO4) = 0.1 mol/L

Standard Tris (hydroxymethyl)-aminomethane (THAM) M = 121.14 g/mol, z = 1

Indication DGi113-SC Combined pH glass electrode

Chemistry HClO4 + C6H7KO2 → C6H7KO2 + KClO4

Calculation Margarine (ppm): R1 = Q*C/m C = M*1000/z Cheese spread/C6H7KO2-Std. (%): R1 = Q*C/m C = M/(10*z) Q = HClO4 consumption in mmol M = Molar mass of C6H7KO2 z = 1

Waste disposal

Final disposal as halogenated, organic waste after neutralization

Author, Version

Sohel R. Ansari / Robin Isyas IMSG Anachem, Sept 2011 Revised: Sept 2011 C. De Caro, MSG AnaChem

http://en.wikipedia.org/wiki/Mold

http://en.wikipedia.org/wiki/Yeast

http://en.wikipedia.org/wiki/Cheese

http://en.wikipedia.org/wiki/Dried_meat

http://en.wikipedia.org/wiki/Dried_meat

http://en.wikipedia.org/wiki/Yogurt

http://en.wikipedia.org/wiki/Wine

http://en.wikipedia.org/wiki/Dried_fruit


Instruments - G20 Compact Titrator Note: The titration can be also performed with the Titration Excellence T50/T70/T90

- XP205 Balance - Thermostatable beaker (ME-00023517)

Accessories - LabX light titration software - DV1010 Burette 10 mL (ME-51107501) - Water circulator bath

Results (Potassium sorbate) All results Method-ID Standard Potassium sorbate Content Potassium sorbate (1/6) R1 (%) 100.416 Content Potassium sorbate (2/6) R1 (%) 100.005 Content Potassium sorbate (3/6) R1 (%) 99.917 Content Potassium sorbate (4/6) R1 (%) 99.874 Content Potassium sorbate (5/6) R1 (%) 99.746 Content Potassium sorbate (6/6) R1 (%) 99.817 Statistics Method-ID Potassium sorbate R1 Samples 6 Mean 99.962 % s 0.239 %

Titration curve (Potassium sorbate)

Sample 1/6 method Potassiumsorbate 9/7/2011 4:46:33 PM


Table of measured values (Potassium sorbate)


mL mL mV mV mV/mL s °C0.0000 NaN 428.1 NaN NaN 0 25.00.0200 0.0200 428.2 0.1 NaN 2 25.00.0400 0.0200 428.4 0.2 NaN 4 25.00.0900 0.0500 428.6 0.2 NaN 7 25.00.2150 0.1250 429.3 0.7 NaN 9 25.00.5275 0.3125 431.2 1.9 5.76 12 25.01.0275 0.5000 434.0 2.8 5.94 16 25.01.5275 0.5000 436.9 2.9 5.91 20 25.02.0275 0.5000 440.0 3.1 5.69 24 25.02.5275 0.5000 442.9 2.9 5.35 28 25.03.0275 0.5000 445.6 2.7 5.09 32 25.03.5275 0.5000 448.1 2.5 4.89 36 25.04.0275 0.5000 450.7 2.6 4.26 40 25.04.5275 0.5000 453.7 3.0 4.15 44 25.05.0275 0.5000 457.9 4.2 10.38 49 25.05.5275 0.5000 463.8 5.9 21.99 55 25.06.0275 0.5000 473.3 9.5 46.83 63 25.06.5275 0.5000 496.2 22.9 114.88 70 25.06.6650 0.1375 530.9 34.7 243.02 73 25.06.6850 0.0200 516.7 -14.2 468.74 78 25.06.7050 0.0200 520.4 3.7 745.69 80 25.06.7550 0.0500 541.7 21.3 997.27 86 25.06.7750 0.0200 561.4 19.7 1151.12 91 25.06.7950 0.0200 623.4 62.0 1193.67 103 25.0

EQP1 6.803200 NaN 646.9 NaN 1219.34 NaN NaN6.8150 0.0200 680.7 57.3 909.9 115 25.06.8350 0.0200 700.6 19.9 921.74 122 25.06.8700 0.0350 715.5 14.9 614.02 126 25.06.9355 0.0655 728.8 13.3 341.21 129 25.07.0600 0.1245 741.5 12.7 158.29 132 25.07.2945 0.2345 752.2 10.7 69.64 135 25.07.7945 0.5000 763.4 11.2 24.66 138 25.08.2945 0.5000 770.3 6.9 NaN 142 25.08.7945 0.5000 775.6 5.3 NaN 145 25.09.2945 0.5000 779.6 4.0 NaN 149 25.09.7945 0.5000 783.2 3.6 NaN 152 25.0

10.0000 0.2055 784.1 0.9 NaN 154 25.0 Sample 1/6 method Potassiumsorbate 9/7/2011 4:46:33 PM

Comments (Potassium sorbate)

• In this case, pure potassium sorbate is used to test the titration method.

• The result indicates the recovery rate of the substance.


Results (Margarine) All results Method-ID Samplepotsor Content Margarine (1/9) R1 (ppm) 5319.712 Content Margarine (2/9) R1 (ppm) 5575.516 Content Margarine (3/9) R1 (ppm) 5436.623 Content Margarine (4/9) R1 (ppm) 5662.005 Content Margarine (5/9) R1 (ppm) 5365.273 Content Margarine (6/9) R1 (ppm) 5491.745 Content Margarine (7/9) R1 (ppm) 5632.622 Content Margarine (8/9) R1 (ppm) 5506.801 Content Margarine (9/9) R1 (ppm) 5342.315 Statistics Method-ID Samplepotsor R1 Samples 9 Mean 5481.401 ppm s 125.536 ppm srel 2.290 % Additional results Margarine n Content (ppm) s (ppm) srel (%) Comments 9 6301.606 127.216 2.019 10 min longer in water bath before titration 9 6371.828 106.070 1.665 10 min longer in water bath before titration

Titration curve (Margarine)

Sample 1/9 method samplepotsor 9/9/2011 10:07:48


Table of measured values (Margarine)


mL mL mV mV mV/mL s °C0.0000 NaN 466.8 NaN NaN 0 25.00.0050 0.0050 467.0 0.2 NaN 3 25.00.0100 0.0050 467.1 0.1 NaN 6 25.00.0225 0.0125 467.3 0.2 NaN 9 25.00.0535 0.0310 467.7 0.4 NaN 12 25.00.1310 0.0775 468.3 0.6 9.53 15 25.00.3250 0.1940 470.1 1.8 9.41 18 25.00.8100 0.4850 474.7 4.6 9.71 21 25.01.3100 0.5000 480.2 5.5 10.76 24 25.01.8100 0.5000 486.6 6.4 13.71 27 25.02.3100 0.5000 494.7 8.1 18.92 31 25.02.8100 0.5000 505.3 10.6 26.22 34 25.03.3100 0.5000 520.1 14.8 33.86 38 25.03.6370 0.3270 533.9 13.8 38.30 41 25.0

EQP1 3.802629 NaN 541.6 NaN 40.99 NaN NaN3.8365 0.1995 543.2 9.3 40.97 44 25.04.0730 0.2365 554.5 11.3 39.43 47 25.04.3170 0.2440 564.3 9.8 34.85 50 25.04.6665 0.3495 575.8 11.5 28.80 53 25.05.1195 0.4530 586.6 10.8 21.59 56 25.05.6195 0.5000 595.3 8.7 NaN 59 25.06.1195 0.5000 602.2 6.9 NaN 62 25.06.6195 0.5000 607.4 5.2 NaN 66 25.07.1195 0.5000 612.0 4.6 NaN 68 25.07.6195 0.5000 616.1 4.1 NaN 72 25.0

Sample 1/9 method samplepotsor 9/9/2011 10:07:48

Comments (Margarine)

• Care has to be taken that margarine is completely dissolved into the solvent. This is achieved by stirring during a long time, and also by warming up the solution to improve the dissolution.

• Since a relatively large sample size is introduced into the titration cell i.e. approx. 10 g, it is necessary to avoid any rest sticking onto e.g. the electrode or the propeller stirrer. In this way, accuracy and reproducibility will be improved.


Results (Cheese spread) All results Method-ID Samplepotsor Content Cheese spread (1/9) R1 (%) 6.887 Content Cheese spread (2/9) R1 (%) 6.901 Content Cheese spread (3/9) R1 (%) 7.032 Content Cheese spread (4/9) R1 (%) 6.965 Content Cheese spread (5/9) R1 (%) 7.039 Content Cheese spread (6/9) R1 (%) 7.020 Content Cheese spread (7/9) R1 (%) 7.009 Content Cheese spread (8/9) R1 (%) 7.143 Content Cheese spread (9/9) R1 (%) 7.031 Statistics Method-ID Samplepotsor R1 Samples 9 Mean 7.003 % s 0.078 % srel 1.108 %

Titration curve (Cheese spread)

Sample 1/9 method samplepotsor 9/9/2011 3:31:04 PM


Table of measured values (Cheese spread)


mL mL mV mV mV/mL s °C0.0000 NaN 465.4 NaN NaN 0 25.00.0050 0.0050 465.7 0.3 NaN 3 25.00.0100 0.0050 465.8 0.1 NaN 6 25.00.0225 0.0125 466.2 0.4 NaN 9 25.00.0535 0.0310 466.8 0.6 NaN 12 25.00.1310 0.0775 468.2 1.4 18.66 15 25.00.3250 0.1940 471.6 3.4 18.23 18 25.00.8100 0.4850 480.4 8.8 17.21 22 25.01.3100 0.5000 490.4 10.0 19.11 25 25.01.8100 0.5000 502.6 12.2 27.47 29 25.02.2935 0.4835 518.0 15.4 46.15 33 25.02.5805 0.2870 531.0 13.0 65.48 37 25.02.7675 0.1870 542.9 11.9 84.07 40 25.02.9030 0.1355 554.4 11.5 101.05 44 25.03.0085 0.1055 565.9 11.5 113.75 48 25.03.0935 0.0850 577.4 11.5 127.50 52 25.03.1650 0.0715 588.3 10.9 142.70 57 25.0

EQP1 3.183257 NaN 591.2 NaN 142.79 NaN 25.03.2355 0.0705 599.4 11.1 142.23 63 25.03.3090 0.0735 610.2 10.8 127.29 68 25.03.3960 0.0870 621.4 11.2 113.11 74 25.03.5030 0.1070 633.1 11.7 98.60 80 25.03.6325 0.1295 644.0 10.9 NaN 86 25.03.8185 0.1860 655.7 11.7 NaN 92 25.04.0725 0.2540 667.6 11.9 NaN 98 25.04.4140 0.3415 678.9 11.3 NaN 105 25.04.9140 0.5000 692.8 13.9 NaN 109 25.0

Sample 1/9 method samplepotsor 9/9/2011 3:31:04 PM

Comments (Cheese spread)

• Care has to be taken that cheese spread is completely dissolved into the solvent. This is achieved by stirring during a long time, and also by warming up the solution to improve the dissolution.

• It is necessary to avoid any rest sticking onto e.g. the electrode or the propeller stirrer. In this way, accuracy and reproducibility will be improved.


Method 001 Title Type General titration Compatible with G20 ID m485G20 Title Potassium sorbate Author LabX-Light Date/Time 07.09.2011 17:35:34 Modified at 14.09.2011 12:55:30 Modified by LabX-Light Protect No SOP None 002 Sample Number of IDs 1 ID 1 Margarine (Potassium sorbate) Entry type Weight Lower limit 0.0 g Upper limit 25.0 g (0.1 g) Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Before 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 180 s Condition No 005 Titration (EQP) [1] Titrant Titrant HClO4

Concentration 0.1 mol/L Sensor Type pH Sensor DG113-SC Unit mV Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Control Normal (User) Mode Acid/base Show parameters Yes Titrant addition Dynamic dE (set value) 12.0 mV dV (min) 0.005 mL (0.02 mL)

dV (max) 0.5 mL Mode Equilibrium controlled dE 0.5 mV (1.0 mV) dt 1.0 s (2.0 mV) t (min) 3 s (2 s) t (max) 30 s (15 s) Evaluation and recognition Procedure Standard Threshold 10 (100 mV/mL) Tendency Positive Ranges 0 Add. EQP criteria None Termination At Vmax 10 mL At potential No At slope No After number of recognized EQPs 1 (No) Combined termination criteria No

006 Calculation R1 Result type Predefined Calculation type Direct titration Result Content Result unit ppm (%) Formula R1=Q*C/m Selected EQP 1 Constant C=M*1000/z ( M/(10*z) ) M M[Potassium sorbate] z z[Potassium sorbate] Decimal places 3 Result limits No Record statistics Yes 007 Record Summary No Results Per sample Raw results Per sample Table of meas. values Last titration function Sample data No Resource data No E - V Last titration function dE/dV - V No log dE/dV - V No d2E/dV2 - V No BETA – V No E - t No V - t No dV/dt - t No T – t No E – V & dE/dV – V No V – t & dV/dt – t No Method No Series data No 008 End of sample



Determination of Milk Fat Content According to CAC/RM 15-1969 Milk fat content is estimated by the determination of the following values obtained by specifically defined empirical methods according to Codex Alimentarius Commission CAC/RM 15-1969: Reichert (R), Polenske (P), and Kirschner (K) values.

Preparation and Procedures Precautions: • Use safety goggles, mask and wear gloves.

Sodium hydroxide 50% m/m: Dissolve sodium hydroxide in an equal mass of water and store the solution in a bottle protected from carbon dioxide.

Diluted sulphuric acid: Dilute approximately 2 mL concentrated sulphuric acid to 1 liter and adjust until 10 ml neutralize 2 ml of the 50% sodium hydroxide solution. General comments: • Clean the burette tip, electrode and stirrer

thoroughly with water after each titration. • During saponification, care has to be taken that

the sample is not overheated. This can be confirmed by checking the color of the solution: if it is darker than pale yellow, then repeat the procedure with new sample.

• During distillation, if the solution starts bumping in Polenske flask, then increase the number of glass beads to be added.

Remarks

Reichert Value (R) – Soluble volatile fatty acids: mL 0.1 M aqueous alkali solution required to neutralize the water soluble fatty acids distilled from 5g of oil or fat under the precise conditions specified in the method.

Polenske Value (P) - Insoluble volatile fatty acids: mL 0.1 M aqueous alkali solution required to neutralize the water insoluble volatile fatty acids distilled from 5g of oil or fat under precise conditions specified in the method.

Kirschner Value (K): mL 0.1 M aqueous alkali solution required to neutralize the water soluble volatile fatty acids which form water soluble silver salts distilled from 5g of oil or fat under the precise conditions specified in the method.

Literature: Estimation of Milk Fat Content, CAC/RM 15-1969. CAC: Codex Alimentarius Commission, FAO, www.fao.org – Section 4. Fats and Oils Derived from Edible Fats and Oils

Sample Clarified butter with total fat not less than 80%.

Compound Fats (triglycerides)

Chemicals • 50% m/m NaOH • Sulphuric acid, H2SO4 • Ethanol, C2H5OH • Glycerol, • Silver sulphate, Ag2SO4

(powdered)

Titrant Barium hydroxide, Ba(OH)2 c(1/2 Ba(OH)2) = 0.1 mol/L

Standard HCl solution, previously standardized with THAM

Indication DGi116-Solvent DGi111-SC

Chemistry Saponification of fat

Calculation Reichert Value (soluble volatile acid)

R1 = (Q/0.1) R2 = 1.10*(R1-B[ReichertBlank]) R1 = mL consumption R2 = Reichert value R Polenske Value (Insoluble volatile acid) R1 = (Q/0.1)-B[PolenskeBlank] R1 = Polenske value P Kirschner Value R1 = (Q/0.1)-B[KirschnerBlank] R2 = 121*(100+H[Reichert cons.])*R1/10000 R3 =(R2-(0.1*H[Polenske Value])-0.24)/0.244 R1 = mL consumption R2 = Kirschner value K R3 = Milk Fat content

Waste disposal

Dispose as organic waste after neutralization.

Author, Version

Robin Isyas, IMSG, Nov 2011 Rev.: C. De Caro MSG AnaChem

http://www.fao.org/

http://upload.wikimedia.org/wikipedia/commons/3/30/SaponificationGeneral.svg


Procedures: Hydrolysis, distillation and titration

Hydrolysis and distillation • Weigh 5 +/- 0.01 g sample in a Polenske flask, add

20g of glycerol and 2 ml of 50% NaOH solution. • Heat it over a naked flame, with continuous mixing

until the liquid becomes clear, avoid over heating. • Make blank test without fat, but using the same

quantities and following the same procedure. • Pour 93 ml of boiling distilled water into the

saponified sample after it has cooled but not solidified.

• If the solution is not clear repeat the saponification with a fresh sample of the fat.

• Add glass beads, followed by 50 ml of the dilute sulphuric acid, and connect the flask at once with distillation apparatus (see comments).

• Heat the flask without boiling its content until the insoluble acids are melted, then increase the flame and distill 110 ml in a flask. Keep the water flowing in the condenser at a temperature between 18oC and 25oC.

• Collect 110 ml of distillate and place in water maintained at 15 oC for 10 minutes. Remove the flask and filter using Whatman no 4 filter. Distillation unit

Titration: • Titrate 100 ml of the filtrate with 0.1 M ½ Ba(OH)2 solution and note down the reading. • Dissolve the insoluble acids by three similar washings of the condenser, the cylinder, and the filter

with 15 ml of neutralized ethanol. • Titrate the alcoholic solution of the insoluble volatile acids with 0.1 M ½ Ba(OH)2 solution, note down

the reading to calculate Polenske Value. • To the solution obtained after performing Reichert value add 0.5 g of powdered silver sulphate, allow

to stand in dark for one hour and then filter. • Transfer 100 ml of the filtrate in a dry Polenske flask, add 35 ml of cold distilled water, 10 ml of dilute

sulphuric acid and add glass beads. • Connect the flask with standard apparatus and again distill 110 ml of the solution as per the previous

distillation procedure. • Titrate 100 ml of the filtrate with 0.1 M ½ Ba(OH)2 solution to obtain Kirschner value. Literature: 1. Determination of (R) and (P) values:

o IUPAC (1966) method (IUPAC Standards Methods for the Analysis of Oils, Fats and Soaps, 5th Edition, 1966, II.D.9, Determination of Soluble and Insoluble Volatile Acids)

o AOAC (1965) method (Official Methods of Analysis of the AOAC,1965, 26.032-26.033). Note: Both the methods of IUPAC and AOAC are necessary because of the extremely empirical nature of the methods depending on regional deviations. Note: Determination of (R) and (P) values are not sufficient for the evaluation of milk fat content in margarine, which also involves the determination of (K) values.

2. Determination of (K) value: o British Standard 684: 1958, Methods of Analysis of Oils and Fats, pages 65-71. o Kirkham (1920) Analyst, 44, 293. o Williams, K.A. (1949) Analyst, 74, 508.


Instruments - Titration Excellence T50/T70/T90 - XP205 Balance

Accessories - LabX Pro titration software - DV1010 10 mL Burette ME-51107501 - PP Titration beaker ME-101974

Results

Sample Reichert value / mL Polenske value / mL Kirschner value / mL Milk fat content / %1 29.804 1.203 21.483 86.5682 29.167 0.838 20.787 83.8663 30.885 1.949 20.419 81.9024 29.221 2.003 20.777 83.3475 29.628 2.308 21.451 85.984

Average 29.741 1.6602 20.9834 84.3334std dev 0.694 0.614 0.466 1.925srel (%) 2.333 36.954 2.220 2.282

Titration curves

Reichert value R:

Polenske value P:

Kirschner value K:


Method – Reichert value R Blank value 001 Title Type General titration Compatible with T50 / T70 / T90 ID ReichertBlank Title Ba(OH)2 Author admin Date/Time 9/16/2011 12:14:41 PM Modified at 10/31/2011 5:17:46 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 0.0 g Upper limit 10.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 10 s Condition No 005 Titration (EP) [1] Titrant Titrant ½ Ba(OH)2 Concentration 0.1 mol/L Sensor Type pH Sensor DG111-SC Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Mode Absolute Tendency None End point value 7.0 pH Control band 1 pH Dosing rate (max) 0.5 mL/min Dosing rate (min) 10 µL/min Termination At EP Yes Termination delay 0 s At Vmax 10.0 mL Max. time infinite Accompanying stating Accompanying stating No Condition Condition No 006 Calculation R1 Result Reichert Blank Result unit mL Formula R1=Q/0.1 Constant C=1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 007 Blank Name ReichertBlank Value B= R1 Unit mL Limits No Condition No 008 End of sample

Sample 001 Title Type General titration Compatible with T50 / T70 / T90 ID ReichertSVA Title Ba(OH)2 Author admin Date/Time 8/16/2011 4:41:55 PM Modified at 11/1/2011 3:19:59 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 0.0 g Upper limit 10.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 10 s Condition No 005 Titration (EP) [1] Titrant Titrant ½ Ba(OH)2 Concentration 0.1 mol/L Sensor Type pH Sensor DG111-SC Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Mode Absolute Tendency None End point value 7.0 pH Control band 2 pH Dosing rate (max) 3 mL/min Dosing rate (min) 10 µL/min Termination At EP Yes Termination delay 0 s At Vmax 35.0 mL Max. time infinite . . . . 006 Calculation R1 Result Consumption Result unit mL Formula R1=(Q/0.1) Constant C=1 M M[None] z z[None] Decimal places 3 . . . . 007 Calculation R2 Result Reichert value Result unit mL Formula R1=

1.10*(R1-B[ReichertBlank]) Constant C=1 M M[None] z z[None] Decimal places 3 . . . . 008 Auxiliary value Name ReichertValue (R) Formula H= R2 Limits No Condition No 009 End of sample


Polenske Value (P) Blank value 001 Title Type General titration Compatible with T50 / T70 / T90 ID PolenskeBlank Title Ba(OH)2 Author admin Date/Time 9/16/2011 12:38:32 PM Modified at 10/13/2011 10:08:40 AM Modified by yp0 Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 0.0 g Upper limit 10.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 10 s Condition No 005 Titration (EP) [1] Titrant Titrant ½ Ba(OH)2 Concentration 0.1 mol/L Sensor Type pH Sensor DG116-Solvent Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Mode Absolute Tendency None End point value 7.0 pH Control band 2 pH Dosing rate (max) 3 mL/min Dosing rate (min) 10 µL/min Termination At EP Yes Termination delay 0 s At Vmax 10.0 mL Max. time infinite Accompanying stating Accompanying stating No Condition Condition No 006 Calculation R1 Result Consumption Result unit mL Formula R1=Q/0.1 Constant C=1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 007 Blank Name PolenskeBlank Value B= R1 Unit mL Limits No Condition No 008 End of sample

Sample 001 Title Type General titration Compatible with T50 / T70 / T90 ID PolenskeValueISVA Title Ba(OH)2 Author admin Date/Time 9/6/2011 3:41:51 PM Modified at 11/1/2011 3:22:45 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 0.0 g Upper limit 10.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 10 s Condition No 005 Titration (EP) [1] Titrant Titrant ½ Ba(OH)2 Concentration 0.1 mol/L Sensor Type pH Sensor DG116-Solvent Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Mode Absolute Tendency Positive End point value 7.0 pH Control band 2 pH Dosing rate (max) 1 mL/min Dosing rate (min) 10 µL/min Termination At EP Yes Termination delay 0 s At Vmax 25.0 mL Max. time infinite Accompanying stating Accompanying stating No Condition Condition No 006 Calculation R1 Result Consumption Result unit mL Formula R1=

(Q/0.1)-B[PolenskeBlank] Constant C=1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 007 Auxiliary value Name PolenskeValue (P) Formula H= R1 Limits No Condition No 008 End of sample


Kirschner Value (K) Blank value 001 Title Type General titration Compatible with T50 / T70 / T90 ID KirschnerBlank Title Ba(OH)2 Author admin Date/Time 9/19/2011 2:54:24 PM Modified at 11/1/2011 3:14:22 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 0.0 g Upper limit 10.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 10 s Condition No 005 Titration (EP) [1] Titrant Titrant ½ Ba(OH)2 Concentration 0.1 mol/L Sensor Type pH Sensor DG111-SC Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Mode Absolute Tendency None End point value 7.0 pH Control band 2 pH Dosing rate (max) 1 mL/min Dosing rate (min) 10 µL/min Termination At EP Yes Termination delay 0 s At Vmax 10.0 mL Max. time infinite Accompanying stating Accompanying stating No Condition Condition No 006 Calculation R1 Result Consumption Result unit mL Formula R1=Q/0.1 Constant C=1 M M[None] z z[None] Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 007 Blank Name KirschnerBlank Value B= R1 Unit mL Limits No Condition No 008 End of sample

Sample 001 Title Type General titration Compatible with T50 / T70 / T90 ID KirschnerSVA Title Ba(OH)2 Author admin Date/Time 9/6/2011 4:20:00 PM Modified at 11/1/2011 3:23:11 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 0.0 g Upper limit 10.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry Arbitrary 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 30% Duration 10 s Condition No 005 Titration (EP) [1] Titrant Titrant ½ Ba(OH)2 Concentration 0.1 mol/L Sensor Type pH Sensor DG111-SC Unit pH Temperature acquisition Temperature acquisition No Stir Speed 30% Predispense Mode None Wait time 0 s Control Mode Absolute Tendency Positive End point value 7.0 pH Control band 2 pH Dosing rate (max) 3 mL/min Dosing rate (min) 10 µL/min Termination At EP Yes Termination delay 0 s At Vmax 25.0 mL Max. time infinite Accompanying stating Accompanying stating No Condition Condition No 006 Calculation R1 Result Consumption Result unit mL Formula R1=

(Q/0.1)-B[KirschnerBlank] . . . . 007 Calculation R2 Result Kirschner Value Result unit mL Formula R2=121*(100+H[ReichertValue(R)])*R1/10000 . . . . 008 Calculation R3 Result Milk Fat Result unit % Formula R3=(R2-(0.1*H[PolenskeValue])-0.24)/0.244 . . . . 009 End of sample


METTLER TOLEDO Application M489-2012 Turbidimetric Titration of Chondroitin Sulfate Sodium according to USP

The content of chondroitin sulfate sodium in dietary supplement tablets is determined by precipitation titration with sodium tetraphenylborate based on United States Pharmacopeia Monograph “Chondroitin Sulfate Sodium”. The titration is monitored by a photometric sensor at 550 nm or 660 nm.

Preparation and Procedures Chondroitin sulfate sodium standard sol. 1 mg/mL: - 100 mg of pure CS sodium is added in a 100

mL volumetric flask and dissolved with 50-60 mL deionized water (concentration: 1 mg/mL).

- 5 mL pH 7.2 phosphate buffer is added.

- Fill with deionized water up to the mark.

Calibration factor titration: - 5 mL CS standard solution is added into the

beaker and diluted with 50 mL deionized water. - The titration for the calibration factor is started.

The result is stored as auxiliary value H3.

Sample solution (1 mg/mL CS): - 5 tablets (400 mg CS) are weighed, added into

a mortar, crushed and mixed to homogenize it. - For a 1 mg/mL CS sample solution, 1/20 of the

total mass of 5 tablets is added into a 100 mL flask, and dissolved with 50-60 mL deion.water.

- 5 mL pH 7.2 phosphate buffer is added. - Fill up to the mark with deionized water.

Sample titration: - 5 mL sample solution is added into the beaker

and diluted with 50 mL deionized water. - The sample titration is started.

Remarks

- Perform your work according to the general laboratory rules and safety regulations.

- After turning on the Phototrode™, wait 15-10 min before starting analysis to achieve a stable signal. Check the transmission signal in deion. water and set it to 1000 mV with the knob.

- Select the appropriate stirring speed to avoid formation of air bubbles during titration since they disturb the photometric indication.

- Sensor, titration tube and stirrer are cleaned after each sample using a conditioning beaker with deionized water.

- The method parameters have been optimized for this sample. It may be necessary to adapt the method to your specific sample.

Sample Dietary supplement tablets (400 mg Chondroitin sulfate sodium) – see procedures

Compound Chondroitin sulfate sodium, CS (C14H19NO14SNa2)n

Chemicals - pH 7.2 phosphate buffer - Deionized water

Titrant Cetylpyridinium chloride monohydrate, CPC, C21H38NCl•H2O c(CPC) = 1 mg/mL = 0.003 mol/L M = 358.01; z = 1

Standard CS standard solution, 1 mg/mL

Indication DP5 Phototrode™ (Wavelengths: 550, 660 nm) or DP550/660 Phototrode™ (DIN-LEMO adapter cable ME-89600) Chemistry Non-stoichiometric reaction

Calculation Calibration factor determ. (DL5x) R1 = VEQ (mL) R2 = Q (mmol) R3 = m*(H1/VEQ)*H2 (mg/mL)

where

m = 5 mL 1 mg/mL CS standard sol. H1 = CS std sol concentration (1 mg/mL) H2 = Purity of CS, e.g. 99.9% = 0.999 The calibration factor R3 is stored as auxiliary value H3.

Sample determination (DL5x) R1 = VEQ (mL) R2 = 20*H3*VEQ (mg) R3 = (R2/(100*C3)*100 (%) C3 = (H4/H5)

where

20 = Dilution factor (5→100 mL) (--) H3 = Calibration factor (mg/mL) H4 = Sample for 1 mg/mL CS (g) H5 = Theor. sample mass (g) needed for 1 mg/mL CS

Waste disposal

General aqueous solutions

Author, Version

C. De Caro - MSG AnaChem March 2001/Revised January 2012


Instruments - DL58 Titrator, or Titration Excellence T50/T70/T90 – minor adaptations - AT261 Balance This method can be run also with the following titrators: DL50/53/55, DL67/70ES/77

Accessories - 10 mL DV1010 burette - Titration beaker ME-101974 - Printer

Results Method CS003: Calibration factor f with CS standard solution – Phototrode @ 550nm Method CS003 Test Solution CS / 550nm 09-Mar-2001 8:21 Measured 09-Mar-2001 16:01 User Cosimo ALL RESULTS No. ID Sample size and results 1 CS100@555 5.0 mL R1 = 7.697 mL Consumption R2 = 0.023 mmol Consumption R3 = 0.7269 mg/mL CS Factor CS 2 CS100@555 5.0 mL R1 = 7.640 mL Consumption R2 = 0.023 mmol Consumption R3 = 0.7324 mg/mL CS Factor CS 3 CS100@555 5.0 mL R1 = 7.670 mL Consumption R2 = 0.023 mmol Consumption R3 = 0.7295 mg/mL CS Factor CS 4 CS100@555 5.0 mL R1 = 7.793 mL Consumption R2 = 0.023 mmol Consumption R3 = 0.7180 mg/mL CS Factor CS STATISTICS Number results R3 n = 4 Mean value x = 0.7267 mg/mL CS Factor CS Standard deviation s = 0.00621 mg/mL CS Factor CS Rel. standard deviation srel = 0.855 % -------------------------------------------------------------------- Method CS004: CS in Tablets – Phototrode @ 550nm Method CS004 CS in Tablets 550nm 09-Mar-2001 16:10 Measured 09-Mar-2001 16:38 User Cosimo ALL RESULTS No. ID Sample size and results 1 Tablet@555 5.0 mL R1 = 7.694 mL Consumption R2 = 111.818 mg CS in sample R3 = 98.71 % Recovery 2 CS100@555 5.0 mL R1 = 7.585 mL Consumption R2 = 110.241 mg CS in sample R3 = 97.31 % Recovery 3 CS100@555 5.0 mL R1 = 7.595 mL Consumption R2 = 110.379 mg CS in sample R3 = 97.43 % Recovery 4 CS100@555 5.0 mL R1 = 7.631 mL Consumption R2 = 110.913 mg CS in sample R3 = 97.91 % Recovery STATISTICS Number results R2 n = 4 Mean value x = 110.838 mg CS in sample Standard deviation s = 0.71495 mg CS in sample Rel. standard deviation srel = 0.645 % STATISTICS Number results R3 n = 4 Mean value x = 97.84 % Recovery Standard deviation s = 0.63111 % Recovery Rel. standard deviation srel = 0.645 %


Titration curves

Calibration factor – CS003 - 09-Mar-2011 16:01 sample 4 Content determination – CS004 - 09-Mar-2011 16:38 sample 4

Tables of measured values

Method CS003 (calibration factor) Volume Increment Signal Change 1st deriv. Time mL mL %T %T %T/mL min:s ET1 0.0000 78.494 0:05 2.0000 2.0000 78.384 -0.110 -0.055 0:15 3.0000 1.0000 78.242 -0.142 -0.142 0:22 ET2 3.5000 0.5000 78.171 -0.071 -0.142 0:57 3.6000 0.1000 78.152 -0.019 -0.194 1:03 3.7000 0.1000 78.126 -0.026 -0.258 1:08 3.8000 0.1000 78.126 0.000 0.000 1:14 3.9000 0.1000 78.152 0.026 0.258 1:19 4.0000 0.1000 78.100 -0.052 -0.517 1:25 4.1000 0.1000 78.152 0.052 0.517 1:30 . . . . . . . . . . . . . . . . . . 7.7000 0.1000 63.231 -4.246 -42.456 5:33 7.8000 0.1000 57.331 -5.900 -58.998 6:03 EQP1 7.9000 0.1000 50.837 -6.494 -64.944 6:33 8.0000 0.1000 46.953 -3.884 -38.837 6:55 8.1000 0.1000 46.740 -0.213 -2.132 7:02

Method CS004 (sample determination) Volume Increment Signal Change 1st deriv. Time mL mL %T %T %T/mL min:s ET1 0.0000 78.824 0:05 2.0000 2.0000 78.591 -0.233 -0.116 0:14 3.0000 1.0000 78.462 -0.129 -0.129 0:22 ET2 3.5000 0.5000 78.326 -0.136 -0.271 0:57 3.6000 0.1000 78.313 -0.013 -0.129 1:03 3.7000 0.1000 78.320 0.006 0.065 1:08 3.8000 0.1000 78.300 -0.019 -0.194 1:15 3.9000 0.1000 78.300 0.000 0.000 1:21 4.0000 0.1000 78.281 -0.019 -0.194 1:26 4.1000 0.1000 78.268 -0.013 -0.129 1:32 4.2000 0.1000 78.223 -0.045 -0.452 1:37 4.3000 0.1000 78.223 0.000 0.000 1:43 4.4000 0.1000 78.210 -0.013 -0.129 1:48 4.5000 0.1000 78.126 -0.084 -0.840 1:55 4.6000 0.1000 78.178 0.052 0.517 2:00 . . . . . . . . . . . . . . . . . . 7.6000 0.1000 63.199 -6.107 -61.066 5:37 7.7000 0.1000 57.086 -6.113 -61.131 6:08 EQP1 7.8000 0.1000 49.150 -7.935 -79.354 6:38 7.9000 0.1000 47.496 -1.654 -16.543 6:48 8.0000 0.1000 46.940 -0.556 -5.557 6:55


Comments

Principle of titration reaction: • Chondroitin sulfate sodium (CS) is precipitated by addition of cationic surfactant cetylpyridinium

chloride (CPC). The solution becomes turbid and has a maximum in turbidity at the equivalence point. According to USP, CS in dietary supplements is determined by turbidimetric titration with the DP5 Phototrode.

• The reaction is not stoichiometric, i.e. there is no well-defined ratio between the amount-of-substance of the two species. Thus, a comparative titration with a CS standard solution is first performed giving a calibration factor indicating the sample amount titrated by 1 mL of titrant (mg/mL).

• The factor is then used in a second titration (sample titration), where the CS-content in the tablets is determined. The calibration factor and the titrant consumption define the amount of CS in the sample.

Titration technique: • Use the same concentration for both methods i.e. calibration factor and sample titration. • Choose the sample volume to get a titrant consumption of about 5 mL in a 10 mL burette.

Calibration factor (method CS003): • According to USP monograph, a 1 mg/mL standard solution of CS is titrated according to method

CS003. This is prepared by weighing dried, pure CS into a volumetric flask. Note that CS is extremely hygroscopic once dried: avoid exposure to atmosphere, and weigh promptly.

• From the titrant consumption VEQ and the known concentration, a calibration factor in R3 is calculated (mg/mL titrant). This can be stored as auxiliary value e.g. H3, and taken into account in the sample titration. In this case, the factor was 0.7267 mg/mL.

• Since no transmission minimum was detected, the titration curve was evaluated by the "Standard" procedure. In this case, the same evaluation must be used for sample titration.

Sample titration (method CS004): • Each tablets contain approx. 400 mg CS. To get a representative amount of the sample, 5 tablets

have been weighed, crushed in a mortar, and homogenized by mixing the powder with a spatula. • To weigh a representative sample containing 100 mg of CS as stated by USP monograph, it is

necessary to divide the total powder mass by 20 (5 tablets à 400 mg = 20 x 100 mg CS). This value is stored as auxiliary value H5.

• This amount is weighed (auxiliary value H4), and dissolved into a 100 mL volumetric flask, and 5 mL aliquots are titrated. The dilution factor 20 (5 mL → 100 mL) is taken into account in calculation R2.

• Finally, the recovery rate (%) for 100 mg CS is given in calculation R3. It is calculated as R3 = (R2/(100*C3))*100 -DL5x-, where C3 = 100 mg x (sample weight / theor. weight) = 100 x (H4/H5) , which is finally multiplied by 100 in order to get %. For Titration Excellence: H4: H[Sample CS] , and H5: H[Theor. Sample]

Structure of chondroitin sulfate sodium:

Chondroitin sulfate (CS) is a dietary supplement which is available as the sodium salt in the form of tablets or capsules. The intake of CS may be an alternative treatment for patients suffering of degenerative joint diseases, such as osteoarthritis. Literature : 1. USP26-NF21, Official Monograph “Chondroitin Sulfate Sodium”, page 2721, 2003, and latest versions. 2. Pharm. Previews «Chondroitin Sulfate Sodium», Pharmacopoeial Forum, Vol. 26(5), Sept.-Oct. 2000, p. 1432.


Method DL5x Titrator (CALIBRATION factor) Method CS003 Test Solution CS / 550 nm Version 09-Mar-2001 8:21 Title Method ID .......................... CS003 Title .............................. Test solution CS/550nm Date/time .......................... 09-Mar-2001 8:21 Sample Sample ID .......................... CS Test s. Entry type ......................... Fixed volume Volume [mL] .................... 5.0 Molar mass M ....................... 1 Equivalent number z ................ 1 Titration stand .................... Stand 1 Temperature sensor ................. Manual Stir Speed [%] .......................... 50 Time [s] ........................... 30 EQP titration Titrant/Sensor Titrant ........................ CPC Concentration [mol/L] .......... 0.003 Sensor ......................... DP550 Unit of meas. .................. %T Predispensing .................. to volume

Volume [mL] .................... 3.5 Wait time [s] .................. 30

Titrant addition ................... Incremental dV [mL] ........................ 0.1 Measure mode ....................... Equilibrium controlled dE [mV] ........................ 1.0 dt [s] ......................... 1.0 t(min) [s] ..................... 5.0

t(max) [s] ..................... 30.0 Recognition Threshold ...................... 40.0 Steepest jump only ............. No Range .......................... No Tendency ....................... Negative Termination at maximum volume [mL] ......... 10.0 at potential ................... No at slope ....................... No after number EQPs .............. Yes

n = ......................... 1 comb. Termination conditions ... No

Evaluation Procedure ...................... Standard Potential 1 ................... No Potential 2 ................... No Stop for reevaluation ......... Yes Condition = ................. neq=0 Calculation Formula ........................... R=VEQ Constant ........................... Decimal places ..................... 3 Result unit ........................ mL Result name ........................ Consumption Statistics ........................ Yes Calculation Formula ........................... R2=Q Constant .......................... Decimal places .................... 3 Result unit ....................... mmol Result name ....................... Consumption Statistics ........................ No Calculation Formula ........................... R3=m*(H1/VEQ)*H2 Constant .......................... Decimal places .................... 4 Result unit ....................... mg/mL CS Result name ....................... Factor CS Statistics ........................ Yes Report Output unit ....................... Printer ... 1. The calibration factor is stored in the setup under

auxiliary value H3 2. 5 mL = sample size of 1 mg/mL CS standard solution 3. H1 = Concentration of pure CS standard solution (mg/mL)

In this case, H1 = 1.108 mg/mL 4. H2 = Purity of CS

In this case, H2 = 1.01 (= 101 %)

Titration Excellence (CALIBRATION factor) 001 Title Type General titration Compatible with T50 / T70 / T90 ID m489A Title Test solution CS/550 nm Author METTLER TOLEDO Date/Time 01.01.2012 15:00:00 . . . 002 Sample Number of IDs 1 ID 1 CS standard sol. Entry type Fixed volume Volume 5.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 40% Duration 30 s 005 Titration (EQP) [1] Titrant Titrant CPC Concentration 0.003 mol/L Sensor Type Phototrode Sensor DP5 Unit %T Temperature acquisition Temperature acquisition No Stir Speed 40% Predispense Mode Volume Volume 3.5 mL Wait time 30 s Control Control User Titrant addition Incremental dV 0.1 mL Meas. val. acquisition Equilibrium controlled dE 1.0 mV dt 1 s t(min) 3 s t(max) 30 s Evaluation and recognition Procedure Standard Threshold 40 %T/mL Tendency Negative Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 006 Calculation R1 Result Consumption Result unit mL Formula R1=VEQ . . . 007 Calculation R2 Result Consumption Result unit mmol Formula R2=Q . . . 008 Calculation R3 Result CS Factor 1 mg/mL Result unit mg/mL Formula R3=m*(H[CS std sol.]/VEQ)*

*H[Purity CS] . . . 009 End of sample 010 Auxiliary value Name Factor CS Formula H= Mean[R3] Limits No 011 Record . . . . .


DL5x Titrator (SAMPLE titration) Method CS004 CS in Tabletten 550 nm Version 09-Mar-2001 16:10 Title Method ID .......................... CS004 Title .............................. CS in Tablets 550 nm Date/time .......................... 09-Mar-2001 16:10 Sample Sample ID .......................... Tablet Entry type ......................... Fixed volume Volume [mL] .................... 5.0 Molar mass M ....................... 1 Equivalent number z ................ 1 Titration stand .................... Stand 1 Temperature sensor ................. Manual Stir Speed [%] .......................... 50 Time [s] ........................... 30 EQP titration Titrant/Sensor Titrant ........................ CPC Concentration [mol/L] .......... 0.003 Sensor ......................... DP550 Unit of meas. .................. %T Predispensing .................. to volume

Volume [mL] .................... 3.5 Wait time [s] .................. 30

Titrant addition ................... Incremental dV [mL] ........................ 0.1 Measure mode ....................... Equilibrium controlled dE [mV] ........................ 1.0 dt [s] ......................... 1.0 t(min) [s] ..................... 5.0

t(max) [s] ..................... 30.0 Recognition Threshold ...................... 40.0 Steepest jump only ............. No Range .......................... No Tendency ....................... Negative Termination at maximum volume [mL] ......... 10.0 at potential ................... No at slope ....................... No after number EQPs .............. Yes

n = ......................... 1 comb. Termination conditions ... No

Evaluation Procedure ...................... Standard Potential 1 ................... No Potential 2 ................... No Stop for reevaluation ......... Yes Condition = ................. neq=0 Calculation Formula ........................... R=VEQ Constant ........................... Decimal places ..................... 3 Result unit ........................ mL Result name ........................ Consumption Statistics ........................ Yes Calculation Formula ........................... R2=20*H3*VEQ Constant .......................... Decimal places .................... 3 Result unit ....................... mg Result name ....................... CS in sample Statistics ........................ Yes Calculation Formula ........................... R3=(R2/(100*C3))*100 Constant .......................... C3=(H4/H5) Decimal places .................... 2 Result unit ....................... % Result name ....................... Recovery Statistics ........................ Yes Report Output unit ....................... Printer ... 1. 20 = Dilution factor (100 mL -> 5 mL) 2. H4 = Sample weighed to get 100 mg CS (g)

In this case, H4 = 0.1928 g 3. H5 = Theoretical sample mass needed to get 100 mg CS (g)

This value is determined by dividing by 20 (5 x 400 mg = 20 x 100 mg CS) the total mass of 5 tablets used to prepare the sample solution. In this case, H5 = 0.17019

Titration Excellence (SAMPLE titration) 001 Title Type General titration Compatible with T50 / T70 / T90 ID m489B Title CS in Tablets / 550 nm Author METTLER TOLEDO Date/Time 01.01.2012 15:00:00 . . . 002 Sample Number of IDs 1 ID 1 Tablet Entry type Fixed volume Volume 5.0 mL Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C 003 Titration stand (Manual stand) Type Manual stand Titration stand Manual stand 1 004 Stir Speed 40% Duration 30 s 005 Titration (EQP) [1] Titrant Titrant CPC Concentration 0.003 mol/L Sensor Type Phototrode Sensor DP5 Unit %T Temperature acquisition Temperature acquisition No Stir Speed 40% Predispense Mode Volume Volume 3.5 mL Wait time 30 s Control Control User Titrant addition Incremental dV 0.1 mL Meas. val. acquisition Equilibrium controlled dE 1.0 mV dt 1 s t(min) 3 s t(max) 30 s Evaluation and recognition Procedure Standard Threshold 40 %T/mL Tendency Negative Ranges 0 Add. EQP criteria No Termination At Vmax 10.0 mL At potential No At slope No After number of recognized EQPs Yes Number of EQPs 1 Combined termination criteria No 006 Calculation R1 Result Consumption Result unit mL Formula R1=VEQ . . . 007 Calculation R2 Result CS in sample Result unit mg Formula R2=20*H[Factor CS]*VEQ . . . 008 Calculation R3 Result Recovery Result unit % Formula R3=(R2/(100*C))*100 Constant C=

(H[Sample CS]/H[Theor. Sample]) . . . 009 End of sample 010 Record . . . . . 1. 20 = Dilution factor (100 mL -> 5 mL) 2. H[sample CS] = Sample weighed to get 100 mg CS (g) 3. H[Theor. Sample]=

Theoretical sample mass needed to get 100 mg CS (g), which is equal to the total mass of all tablets divide by the number of tablets used.

METTLER TOLEDO Page 1 of 4 Titration Application M304-09A

METTLER TOLEDO Application M304-09A Water Determination in Milk Powder (Internal Extraction with Homogenizer)

The water determination of milk powder is performed by volumetric Karl Fischer titration with a homogenizer.

Preparation and Procedures - Before analysis, the concentration determination

is performed by running method M300 (Water Standard 10.0 mg/g).

- The titration vessel needs to be filled with more solvent i.e. 120 mL. This is due to the fact that the dispersing aggregate of the homogenizer has to be immersed into the solvent for at least 2 cm.

- Add the milk powder with a glass weighing boat.

Remarks

- The homogenizer time should be 60-90 s.

- Use an additional mix time of 15 s after homogenizing.

- Do not use the parameter “Autostart”!

- The concentration is calculated according to the formula:

CONC = CONT*10*m/(VEQ-(DRIFT/CONC(alt))*TIME/1000)

CONT = Conc. of liquid water standard (%) CONC(alt) = CONC(alt) refers to the setup value at the time of calculation.

Reference:

For more detailed information on this application and on how to connect the homogenizer, please refer to:

METTLER TOLEDO Applications Brochure 27, “Karl Fischer Titration with An Homogenizer: An Introduction with Practical Examples” 08/2000, ME-51 725 053.

Sample 0.1 – 0.2 g milk powder

Compound Water, H2O M = 18.01 g/mol

Chemicals 120 mL methanol as a solvent

Titrant HYDRANAL® -Composite 5 (5 mg H2O/mL), or CombiTitrant 5 apura® (5 mg H2O/mL)

Standard Water Standard 10.0 mg/g (HYDRANAL® Water Standard 10.0)

Indication DM143-SC Electrode

Chemistry CH3OH + SO2 + 3 RN + I2 + H2O → (RNH)•SO4CH3 + 2 (RNH)I

Calculation Water content in %:

VEQ*CONC-(TIME*DRIFT/1000)*C/m

VEQ: Titrant consumption to EP TIME: Total time since sample request C 0.1

Waste disposal

Organic solvents

Author, Version

Market Support Group Anachem, Maria José Schmid, August 2009


Instruments - KF Compact Volumeter V30 (V2.0), Titration Excellence T70/T90 (V3.1.1) - Adapter Set 12, ME-51 107 534 (For Kinematica Polytron PT1200)

Note: The homogenizer must be purchased from the producer/Not a MT product - TBox DR42

Accessories - XP205 Balance - LabX Titration Software - Glass weighing boat ME-23952

Results Sample: Milk powder Titrant: HYDRANAL®-Composite 5 No. Comment / ID Start time Sample size and results

1/6 -- 21.08.2009 10:02:31 0.1114 g R1 = 5.59 % Content 2/6 -- 21.08.2009 10:15:00 0.1002 g R1 = 5.61 % Content 3/6 -- 21.08.2009 10:32:54 0.1146 g R1 = 5.57 % Content 4/6 -- 21.08.2009 11:23:04 0.1078 g R1 = 5.45 % Content 5/6 -- 21.08.2009 11:41:45 0.1036 g R1 = 5.53 % Content 6/6 -- 21.08.2009 11:52:32 0.1053 g R1 = 5.69 % Content

Statistics Rx Name n Mean value Unit s srel[%]

R1 Content 6 5.57 % 0.08 1.443 Additional results R1 Content 4 5.40 % 0.12 2.141

Titration curve

Sample 1/6



Volume Increment H2O Online drift Signal Change Time mL mL mg µg/min mV mV s 0.00000 NaN 0.0000 0.0 794.0 NaN 0 0.00000 0.00000 0.0000 0.0 793.8 -0.2 0 0.00000 0.00000 0.0000 0.0 794.0 0.2 1 0.00000 0.00000 0.0000 0.0 794.0 0.0 2 0.00150 0.00150 0.0075 144.5 792.9 -1.1 3 0.01425 0.01275 0.0710 1064.7 788.9 -4.0 4 0.02700 0.01275 0.1345 1646.8 784.0 -4.9 5 0.04350 0.01650 0.2167 2241.5 773.8 -10.2 6 0.05925 0.01575 0.2951 1940.4 777.6 3.8 7 0.05975 0.00050 0.2976 2330.0 788.0 10.4 8 0.07100 0.01125 0.3537 2100.9 788.6 0.6 9 0.08300 0.01200 0.4134 2257.4 787.8 -0.8 10 … … … … … … … 1.26050 0.00025 6.2788 118.4 0.3 0.3 203 1.26050 0.00000 6.2788 118.4 -1.4 -1.4 204 1.26125 0.00075 6.2825 103.6 -0.8 -0.8 205 1.26125 0.00000 6.2825 103.6 -3.1 -3.1 206 1.26125 0.00000 6.2825 59.2 2.0 2.0 207 1.26125 0.00000 6.2825 59.2 -0.5 -0.5 208 1.26125 0.00000 6.2825 59.2 3.7 3.7 209 1.26125 0.00000 6.2825 59.2 -3.1 -3.1 210 1.26125 0.00000 6.2825 59.2 1.3 1.3 211 1.26125 0.00000 6.2825 59.2 0.8 0.8 212 1.26125 0.00000 6.2825 29.6 -0.5 -0.5 213 1.26125 0.00000 6.2825 22.2 -0.4 -0.4 213

Sample 1/6

Comments - The homogenizer is controlled by TBox and is mounted in the titration stand.

- An additional power cable for the connection from the TBox DR42 to the power supply unit of the homogenizer is needed. This cable is commercially available in any electronics and electrical components shop.

- For this, a special cover is needed for the titration vessel as well as an adapter. These parts are contained in the Adapter Set 12 (ME-51 107 534). This adapter set can be used with the Polytron 1200 Homogenizer and the PT-DA 1212/2EC of Kinematica. The dispersing aggregate has a diameter of 12 mm.

- There is also the possibility of using a homogenizer with a larger diameter (18 mm). This homogenizer can be purchased from IKA. For this homogenizer it is necessary to use the Adapter Set 18 (ME-51 107 409).

- The use of the homogenizer in combination with a KF Volumetric Instrument is described in detail in Titration Applications Brochure No. 27 (ME-51 725 053)

- The homogenizers are not Mettler-Toledo products and therefore they cannot be purchased from Mettler-Toledo. The homogenizer has to be purchased from the producers:

12 mm Homogenizer: Kinematica www.kinematica.ch

18 mm Homogenizer: IKA www.ika.de

http://www.kinematica.ch/

http://www.ika.de/


Method (V2.0) 001 Title Type Karl Fischer titration Compatible with T70/T90/V30 ID M304 Title Milk powder (homogenizer) Author METTLER TOLEDO Date/Time 02.08.2006 15:00:00 Modified at 02.08.2006 15:00:00 Modified by METTLER TOLEDO Protect No SOP None 002 Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit 0.1 g Upper limit 1.0 g Density 1.0 g/mL Correction factor 1.0 Weight per piece 1.0 g Temperature 25.0°C Autostart No Entry After addition Concentration Titrant KF 1-comp 5 Nominal concentration 5 mg/mL Standard Water-Standard 10.0 Entry type Weight Lower limit 0.0 g Upper limit 2.0 g Temperature 25.0°C Mix time 10 s Autostart Yes Entry After addition Concentration limits Yes Lower limit 4.5 mg/mL Upper limit 5.6 mg/mL 003 Titration stand (KF stand) Type KF stand Titration stand KF stand Source for drift Online Max. start drift 25 µg/min 004 Homogenizer Name Homogenizer TTL Duration 60 s 005 Mix time Duration 15 s 006 Titration (KF Vol) [1] Titrant Titrant KF 1-comp 5 Nominal concentration 5 mg/mL Reagent type 1-comp Sensor Type Polarized Sensor DM143-SC Unit mV Indication Voltametric Ipol 24.0 µA Stir Speed 35 % Predispense Mode None Wait time 0 s Control End point 100.0 mV Control band 400.0 mV Dosing rate(max) 5 mL/min Dosing rate(min) 80 µL/min Start Normal Termination Type Drift stop relative Drift 15.0 µg/min At VMax 10.0 mL Min. time 0 s Max. time infinity

007 Calculation R1 Result tape Predefined Result Content Result unit % Formula R1=(VEQ*CONC-

TIME*DRIFT/1000)*C/m Constant C= 0.1 Decimal places 2 Result limits No Record statistics Yes Extra statistical functions No 007 Record Summary Per sample Results No Raw results No Table of measured values No Sample data No Resource data No E-V curve No E-t curve No V-t curve No H2O-t No Drift-t No H2O-t & Drift-t curves No V-t & drift-t No Method No Series data No 008 End of sample Open series Yes


METTLER TOLEDO Application M306-09A Water Determination in Corn Starch with Drying Oven DO308

The water content in corn starch is determined by volumetric Karl Fischer titration using a drying oven.

Preparation and Procedures Preparation DO308/air pump: - The oven must first be heated out (incl. aluminum

boat) at 300°C for approx. 20 min until the drift is less than 10 µg/min before starting measurement (see operating instruction for DO308), the air gas flow rate is adjusted to 200 mL/min.

- Set the temperature for the sample measurement to 180°C.

Sample measurement: - The titrator is in Stand-by. - Weigh the sample in a glass weighing boat and tare it. - Open the valve of the DO308 oven in order to stop the

air flowing into the titration cell. - The sample is transferred into the aluminum boat of

the DO308 through the sample opening on the oven tube.

- Press start sample and close the valve to allow for air flowing into the titration cell.

- Push the oven boat into the heating zone of the oven. - Back weighing the empty glass boat and enter the

sample size. Remarks

- The concentration of the titrant should be determined first with method M300 and approx. 1 g of 10.o mg H2O /g water standard is used:

Titer (n=3):

(4.901135 ± 0.011893) mg/mL (srel: 0.243%)

- The transfer of the sample into the DO308 has to be done very carefully to reduce the error of the sample size. An alternative sample transfer is also show (see “Comments”).

Sample Corn starch, 0.1 g


Chemicals 60 mL HYDRANAL® -Methanol Dry or 60 mL CombiMethanol apura®

Titrant HYDRANAL® -Composite 5 (5 mg H2O/mL), or CombiTitrant 5 apura® (5 mg H2O/mL)

Standard Water Standard 10.0 mg/g (Merck® Water Standard 1.0%)


Chemistry CH3OH + SO2 + 3 RN + I2 + H2O → (RNH)SO4CH3 + 2 (RNH)I

Calculation Water content in ppm:

(VEQ*CONC-(TIME*DRIFT/1000)) * C -----------------------------------------------------

m VEQ: Titrant consumption to EP TIME: Duration of a sample analysis from the end of Standby until the end of the method function Titration (KF Vol) C: 1000 (constant for ppm calc.)

Waste disposal

Organic solvents

Author, Version

Cosimo De Caro, MSG July 2009


Instruments - KF Compact Line Volumeter V20/V30 (V2.0) - Titration Excellence T70/T90 (V3.1.1) - KF drying Oven DO308 with drying unit (silica gel, molecular sieve) and air pump - XP205 Balance

Accessories - LabX Titration Software - Glass weighing boat ME-23952 - 10 mL syringe with needle

Results No. Comment / ID Start time Sample size and results

1/6 Corn starch 28.07.2009 09:50:36 0.0969 g R1 = 13.29 % Content 2/6 Corn starch 28.07.2009 10:15:08 0.1308 g R1 = 13.21 % Content 3/6 Corn starch 28.07.2009 10:32:54 0.1327 g R1 = 13.30 % Content 4/6 Corn starch 28.07.2009 10:54:45 0.1075 g R1 = 13.25 % Content 5/6 Corn starch 28.07.2009 11:12:33 0.0997 g R1 = 13.27 % Content 6/6 Corn starch 28.07.2009 11:30:22 0.1342 g R1 = 13.39 % Content Statistics Rx Name n Mean value Unit s srel[%]

R1 Content 6 13.28 % 0.06 0.456

Titration curve

sample 1/6



Volume Increment H2O Online drift Signal Change Time mL mL mg µg/min mV mV s 0.00000 NaN 0.0000 0.0 594.3 NaN 0 0.00000 0.00000 0.0000 0.0 594.3 0.0 0 0.00000 0.00000 0.0000 0.0 594.4 0.1 1 0.00100 0.00100 0.0049 146.9 594.4 0.0 2 0.00575 0.00475 0.0282 563.6 593.6 -0.8 3 0.01425 0.00850 0.0698 1047.6 589.0 -4.6 4 0.02700 0.01275 0.1323 1587.9 587.5 -1.5 5 0.04375 0.01675 0.2144 2144.2 579.7 -7.8 6 0.06450 0.02075 0.3161 2709.6 570.8 -8.9 7 0.08450 0.02000 0.4141 3106.1 562.6 -8.2 8 0.10125 0.01675 0.4962 3308.3 567.0 4.4 9 0.12225 0.02100 0.5992 3595.0 567.3 0.3 10 0.14150 0.01925 0.6935 4119.9 570.0 2.7 11 0.17350 0.03200 0.8503 5022.5 494.1 -75.9 12 0.25125 0.07775 1.2314 7147.9 63.5 -430.6 13 0.25125 0.00000 1.2314 6900.4 485.8 422.3 14 0.25425 0.00300 1.2461 6616.6 569.7 83.9 15 0.28150 0.02725 1.3797 6922.3 509.3 -60.4 16

2.62700 0.00000 12.8753 21.8 88.1 9.3 895 2.62700 0.00000 12.8753 14.6 84.1 -4.0 896 2.62700 0.00000 12.8753 14.6 86.3 2.2 897 2.62700 0.00000 12.8753 14.6 83.4 -2.9 898 2.62700 0.00000 12.8753 7.3 87.5 4.1 899 2.62700 0.00000 12.8753 0.0 96.1 8.6 900

Sample 1/6

Principle DO308 KF Oven: Mechanism of the sample transport with magnet

Slider

Guide rod with magnet

Glass sample boatSlider

Guide rod with magnet

Glass sample boat


Comments - The drying oven can be used for different samples; it is especially used for samples which would give

side reactions with the Karl Fischer reagent by direct measurement.

- It is important to know about the thermal decomposition of the measured sample at a specific temperature. In fact, decomposition product such as for instance CO2, reacts with iodine leading to a higher water content. In such case, the external extraction with e.g. chloroform would be the most suitable method for sample prearation. Example:

Sample Method H2O content (%)

Washing powder (Migros)

DO308, 150°C, 900s, 200 mL/min N2 10.6 ± 0.4

External extraction with CHCl3 for 2h 1.0 ± 0.03

Alternative solution for sample transfer and weighing: - Weigh a small funnel with a 100 mL glass beaker (W1). - Weigh the sample in a metal weighing boat (ME-4507) and tare it (see photograph below). - Press start sample, transfer it with the funnel in the aluminum boat of the DO308 and push it into the

heating zone of the oven. - Back weighing the empty metal boat (S1). - Weigh the funnel with the glass beaker (W2). Calculation of the sample weight: Sample weight = [S1] - ([W2] – [W1])

Sample preparation:

Sample in metal weighing boat

Transfer of the sample into drying oven


Method (V2.0) 001 Title Type Karl Fischer titration Compatible with T70/T90/V20/V30 ID M306 Title Corn starch (manual oven) Author METTLER TOLEDO Date/Time 27.07.2009 14:59:07 Modified at 28.07.2009 14:05:33 Modified by METTLER TOLEDO Protect No SOP None 002 Sample Number of IDs 1 ID 1 Corn starch Entry type Weight Lower limit 0.0 g Upper limit 0.15 g Density 1.0 g/mL Correction factor 1.0 Weight per piece 1.0 g Temperature 25.0°C Autostart No Entry Arbitrary Concentration Titrant KF 1-comp 5 Nominal concentration 5 mg/mL Standard Water-Standard 10.0 Entry type Weight Lower limit 0.0 g Upper limit 2.0 g Temperature 25.0°C Mix time 10 s Autostart Yes Entry After addition Concentration limits Yes Lower limit 4.5 mg/mL Upper limit 5.6 mg/mL 003 Titration stand (KF stand) Type KF stand Titration stand KF stand Source for drift Online Max. start drift 25 µg/min 004 Mix time Duration 60 s 005 Titration (KF Vol) [1] Titrant Titrant KF 1-comp 5 Nominal concentration 5 mg/mL Reagent type 1-comp Sensor Type Polarized Sensor DM143-SC Unit mV Indication Voltametric Ipol 24.0 µA Stir Speed 35 % Predispense Mode None Wait time 0 s Control End point 100.0 mV Control band 350.0 mV Dosing rate(max) 5 mL/min Dosing rate(min) 80 µL Start Normal Termination Type Delay time Drift 10 s At VMax 10.0 mL Min. time 900 s Max. time 900 s 006 Calculation R1 Result tape Predefined Result Content Result unit % Formula R1=(VEQ*CONC-

TIME*DRIFT/1000)*C/m Constant C= 0.1 Decimal places 2 Result limits No Record statistics Yes Extra statistical functions No

007 Record Summary Per sample Results No Raw results No Table of measured values No Sample data No Resource data No E-V curve No E-t curve No V-t curve No H2O-t No Drift-t No H2O-t & Drift-t curves No V-t & Drift-t No Method No Series data No 008 End of sample Open series Yes



KF Coulometry: Surface Water in Brown Sugar by External Extraction The surface water of brown sugar was determined by external extraction with chloroform as a solvent, and subsequent coulometric Karl Fischer titration.

Preparation and Procedures - To determine the surface water of sugar, the

moisture has to be first extracted into an organic solvent which is not dissolving the sample.

- In our case, chloroform has been selected. In this solvent, brown sugar is (almost) insoluble.

- The external extraction is performed into a flask with septum.

External extraction: 22 g sample in 135 g chloroform. Extraction times: Various extraction times (see Remarks, Comments); Chloroform aliquot (sample size): 1-4 g.

Remarks

- The extracted water content increases with increasing time and reaches equilibrium after approximately 24 hrs (see graph in “Comments”).

- To completely extract surface water, an extraction time of 15-30 min is recommended.

- A time dependence was noticed:

Time/hrs Mean/ppm (n = 6) srel/% 0.5 56.9 9.5 1.5 79.2 6.1 2.0 103.1 5.4 24.0 286.4 2.5 72.0 300.8 3.1

- The blank value of the solvent chloroform was

determined prior to the external extraction – Result: 7.3 ppm (n = 4).

- For low water content (short extraction time) the generator current (function no. 005: Control) can be set to a fix value of 200 mA to get more data points and avoid overtitration.

Sample Brown Sugar


Chemicals Chloroform (e.g. Fluka – puriss., > 99.8%)

Titrant In situ electrochemically generated iodine, I2 : - 100 mL HYDRANAL® Coulomat AD

Standard --


Chemistry CH3OH + SO2 + 3 RN + I2 + H2O → (RNH)•SO4CH3 + 2 (RNH)I

Calculation Water content in ppm: R1 = (pw(6)/(pw(6)-C)) * *(C*msol/mext-B*msol/mext) C: (ICEQ/10.712-TIME*DRIFT)/m msol: Solvent weight for titrations of

type KF ext. extraction. mext: Extracted sample quantity for

titrations of type KF ext. extr. B: Blank (water cont. of the solvent)

Waste disposal

Organic solvents

Author, Version

MSG Anachem Group Thomas Hitz, Dec 2008


Instruments - KF Compact Coulometer C30X (X: Generating cell without diaphragm)

Accessories - XS205 Balance - LabX Titration Software

Results All results Method-ID M394 Sample Brown sugar (1/6) R1 (Content) 63.9 ppm Sample Brown sugar (2/6) R1 (Content) 55.6 ppm Sample Brown sugar (3/6) R1 (Content) 51.9 ppm Sample Brown sugar (4/6) R1 (Content) 50.7 ppm Sample Brown sugar (5/6) R1 (Content) 60.4 ppm Sample Brown sugar (6/6) R1 (Content) 59.3 ppm Statistics Method-ID M394 R1 Content Samples 6 Mean 56.9 ppm s 5.1 srel 9.5 %

Titration curve

0

50

100

150

200

250

300

0 100 200 300 400 500 600

Consumption / mC

Sign

al /

mV


Table of measured values Consumption Increment H2O Online drift Signal Change Time mC mC µg µg/min mV mV s 0.4 NaN 0 0 274.5 NaN 0 228.6 228.2 21.3 317.5 233.5 -41 2 438.9 210.3 41 1063.7 157.1 -76.4 3 480.8 41.9 44.9 1027.3 90.7 -66.4 4 480.8 0 44.9 527.5 85.1 -5.6 5 480.8 0 44.9 283.5 82.1 -3 6 480.8 0 44.9 184.1 84.8 2.7 7 480.8 0 44.9 121.5 85 0.2 8 480.8 0 44.9 81 81.3 -3.7 9 480.8 0 44.9 63.3 86.1 4.8 10 480.8 0 44.9 28.6 85.7 -0.4 11 480.8 0 44.9 13.2 83.1 -2.6 12 480.8 0 44.9 11.2 84.7 1.6 13 480.8 0 44.9 9.6 85.2 0.5 14 480.8 0 44.9 8.3 84.1 -1.1 15 480.8 0 44.9 7.3 87.3 3.2 16 480.8 0 44.9 6.4 85 -2.3 17 480.8 0 44.9 5.7 86.9 1.9 18 480.8 0 44.9 0 85.5 -1.4 19

Comments

- The surface water was determined as a function of the extraction time. It is clearly visible in the graph

that the water content is increasing with increasing extraction time. A constant value is reached after approximately 25 h.

- The increase can be also explained by partial dissolution of sugar in chloroform. This is supported by the turbid extraction solution.

0

20

40

60

80

100

120

0 1 2 3

020406080

100120

0 1 2 3


001 Title Type KF Coulometric Compatible with C30 ID M394 Title Sugar Author METTLER TOLEDO Date/Time 24.11.2008 12:03:01 Modified at -- Modified by -- Protect No SOP None 002 Sample Sample Number of IDs 1 ID 1 -- Entry type Weight Lower limit[g] 0.0 Upper limit [g] 5.0 Density [g/mL] 1.0 Correction factor 1.0 Temperature [°C] 25.0 Autostart Yes Entry After addition Blank Source for blank Setup Blank Blank KF Unit ppm Entry type Weight Lower limit [g] 0.0 Upper limit [g] 5.0 Temperature [°C] 25.0 Mix time [s] 15.0 Autostart Yes Entry After addition Limits No 003 Titration stand (KF stand) Type KF stand Titration stand KF stand Source for drift Online Max. start drift 25 µg/min 004 Mix time Duration [s] 15 005 Titration (KF Coul) [1] Sensor Type Polarized Sensor DM143-SC Unit mV Indication Voltametric Ipol [µA] 5 Stir Speed [%] 45 Control End point [mV] 100.0 Control band [mV] 250.0 Rate Cautious Generator current Automatic Termination Type Drift stop relative Drift 3.0 µg/min Min. time [s] 0 Max. time [s] 3600 006 Calculation R1 Result type Predefined Result External extraction

(B in ppm) Result unit ppm Formula R1= pw(6)/(pw(6)-C)*

*(C*msol/mext-B*msol/mext) Constant C= (ICEQ/10.712-TIME*DRIFT)/m Decimal places 1 Result limits No Record statistics Yes Extra statistical func. No

007 Record Summary Per sample Results No Raw results No Table of measured values No Sample data No Resource data No E-V curve No E-t curve No V-t curve No H2O-t No Drift-t No H2O-t & Drift-t curves No V-t & drift-t No Method No Series data No 008 End of sample Open series Yes

Method


METTLER TOLEDO Application M490-2012 Water Content in Oils by KF Coulometry at High Temperature (40-50°C)

Precision study for moisture determination in oils by coulometer at high temperatures by means of a thermostatable titration cell. The results have been compared to the ones obtained with the KF Oven sample changer.

Preparation and Procedures Precautions: - Use safety goggles, wear gloves and a lab coat,

- Due to the evaporation of organic solvents present in the water standards, use a mask or work in a fume hood.

Procedures: - The analyst must ensure that there is a stable

and constant drift value before every titration.

- Great care must be taken to get high accuracy and precision since water standards 1.0 mg/g and 0.10 mg/g are hygroscopic).

Comparative study: - A comparative study has been performed to

compare the results of moisture determination in motor oil by manual heating to 45°C by water jacket with that obtained with the Stromboli Karl Fischer Oven Sample Changer at 170° C.

Remarks

- The greatest error in Karl Fischer titration is in the sample handling. For instance, the balance reading has to be perfectly stable when the weight is taken. If the weight is slightly drifting, then these small deviations can be significant.

- As a consequence, a balance with a resolution of 0.01 mg is needed to get accurate results.

- Before filling the syringe completely with the water standard (hygroscopic!), fill it with a little bit of water standard, gently shake the syringe in order to wash away adherent moisture with the water standard, and finally discard it.

- The sample size was optimized in order to improve complete dissolution of oil samples into the electrolyte i.e. a minimum sample size was selected to achieve several sample injections before replacing electrolyte.

- At 45-55°C the color of the electrolyte solution changed from pale yellow to fluorescent green. According to the technical support of KF electrolyte producer, the solution is stable and the color is due to contamination.

Sample - Sesame oil, coconut oil, paraffin oil, clarified butter

- Motor oil.

Compound Water, H2O, M(H2O) = 18.01 g/mol

Chemicals --

Titrant HYDRANAL® Coulomat AG (Riedel-de Haën Prod. No. 34836)

Standard HYDRANAL®- Water Standard 1.00 (Riedel-de Haën Prod. no. 34828) HYDRANAL®- Water Standard 0.10 (Riedel-de Haën Prod. no. 34847) Apura water standard 0,01% (MERCK Prod. no. 1.88050.0010)

Indication DM143-SC double platinum pin polarized electrode

Chemistry CH3OH + SO2 + 3 RN + I2 + H2O → (RNH)∙SO4CH3 + 2 (RNH)I

Calculation R1 = (ICEQ/10.712-TIME*DRIFT)/(C*m) C = 1 Result unit = ppm

Waste disposal

Organic solvents

Author, Version

Robin Isyas, IMSG, January 2012 Revised: Cosimo De Caro, MSG AnaChem, March 2012


Results

Sample Series Temperature Moisture content Certified value SD RSD

Date & time °C ppm (Mean value) of water standard ppm %

1000 ppm water standard 2/1/2012 14:33 25 998.937 999 ppm 1.698 0.170

Sesame oil 3/1/2012 9:44 25 679.717 6.394 0.941

Coconut oil 5/1/2012 12:19 25 761.155 5.951 0.782

Motor oil 19/1/2012 11:56 25 144.492 4.643 3.213

Paraffin oil 5/1/2012 11:31 25 35.260 1.943 5.516 100 ppm water

standard 5/1/2012 14:00 25 91.539 93 ppm 1.002 1.094

1000 ppm water

standard 9/1/2012 16:54 35 994.750 999 ppm 2.420 0.243

Sesame oil 9/1/2012 14:33 35 637.196 7.559 1.186

Coconut oil 9/1/2012 12:49 35 759.088 5.564 0.733

Clarified butter 9/1/2012 17:23 35 396.522 3.906 0.985

Motor oil 19/1/2012 10:37 35 164.543 2.159 1.312


standard 17/1/2012 17:10 35 112.178 108 ppm 0.956 0.852

1000 ppm water

standard 11/1/2012 13:50 45 994.834 999 ppm 1.222 0.123

Sesame oil 11/1/2012 12:53 45 639.430 5.507 0.861

Coconut oil 11/1/2012 10:30 45 784.571 3.764 0.480


Motor oil 18/1/2012 16:23 45 187.447 3.873 2.066


standard 17/1/2012 17:32 45 108.873 108 ppm 1.803 1.656

1000 ppm water

standard 13/1/2012 11:40 55 1006.635 1003 ppm 2.594 0.258

Sesame oil 13/1/2012 11:06 55 613.252 9.338 1.523

Coconut oil 13/1/2012 9:04 55 781.873 8.859 1.133


Motor oil 19/1/12012 9:21 55 199.368 5.431 2.724


standard 18/1/2012 11:21 55 97.444 93 ppm 0.466 0.479

Instruments - C30X Compact KF Coulometer with Cell without diaphragm - Stromboli KF Oven Sample Changer with heated tube and glass tube for oils - XS205 Balance

Accessories - LabX titration pro - Escy water heater – water bath circulator - 5 ml plastic syringe for water standards and samples.


Titration curve - Motor oil 20/1/2012 15:35

Table of measured values - Motor oil 20/1/2012 15:35

Comments

Comparison of results obtained by precision study of Motor oil by heating at 45° C by means of thermostatable titration cell and that by using Stromboli for moisture determination.

Sample Moisture content (ppm) Moisture content (ppm)

Motor oil

Heating at 45°C 20/1/2012 15:35 Stromboli results at 170°C 20/1/2012 13:30

136.292 135.083

140.179 137.996

136.758 146.321

141.359 138.147

136.372 137.71

Mean value 138.192 139.051

Std dev 2.3956 4.2522

RSD 1.734 3.058

Conclusion: From the above data it can be concluded that the results obtained by Stromboli and that by analysis at 45° C are comparable.


Methods

Method – manual titration (C30) 001 Title Type KF Coulometric Compatible with C20/30 ID Hightempprecision Title Water standard 1 Author admin Date/Time 1/2/2012 2:32:12 PM Modified at 1/3/2012 3:58:37 PM Modified by admin Protect No SOP None 002 Sample Number of IDs 1 ID 1 std 1 Entry type Weight Lower limit 0.0 g Upper limit 2.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Entry After addition 003 Titration stand (KF stand) Type KF stand Titration stand KF stand Source for drift Determination Max.start drift [ug/min] 25 004 Mix time Duration 10 s 005 Titration (KF Coul) [1] Sensor Type Polarized Name DM143-SC Unit mV Indication Voltametric Ipol [uA] 5.0 Stir Speed 50 % Control End point [mV] 100.0 Control band [mV] 400 Rate Normal Generator current Automatic Termination Type Drift stop relative Drift [ug/min] 3.0 Min. time [s] 0 Max. time [s] 3600 006 Calculation R1 Result type Predefined Result Content Result unit ppm Formula R1=

ICEQ/10.712-TIME*DRIFT)/(C*m) Constant C=1 Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No 007 Record Summary Per sample . . . 008 End of sample Open series Yes ------------------------------------------------------------

Method – Automated KF Oven (Stromboli) 001 Title Type Stromboli Compatible with C30 ID MOTOROIL Title MMOTOR OIL Author administrator Date/Time 1/19/2012 3:38:19 PM Modified at 1/20/2012 1:29:57 PM Modified by admin Protect No SOP None 002 Drift determination Wait time [s] 60 Duration [min] 2 003 Sample Number of IDs 1 ID 1 BLANK Entry type Weight Lower limit 0.0 g Upper limit 5.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Analysis start Start manually Entry Arbitrary

004 Titration stand (Stromboli TTL) Type Stromboli TTL Titration stand Stromboli TTL 1 Oven temperature [°C] 170 Source for drift Determination Max.start drift [ug/min] 25 005 Mix time Duration 60 s 006 Titration (KF Coul) [1] Sensor Type Polarized Name DM143-SC Unit mV Indication Voltametric Ipol [uA] 5.0 Stir Speed 40 % Control End point [mV] 100.0 Control band [mV] 400 Rate Normal Generator current Automatic Termination Type Drift stop relative Drift [ug/min] 10.0 Min. time [s] 30 Max. time [s] 600 007 Calculation R1 Result Stromboli blank value Result unit µg Formula R1=(ICEQ[1]/10.712-

TIME[1]*DRIFT)/C Constant C=1 Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No 008 End of sample 009 Blank Name Blank Stromboli Value B Mean [R1] Unit µg Limits No 010 Sample Number of IDs 1 ID1 Motor Oil Entry type Weight Lower limit [g] 0.0 Upper limit [g] 5.0 Density [g/mL] 1.0 Correction factor 1.0 Temperature [°C] 25.0 Entry Arbitrary 011 Titration stand (Stromboli TTL) Type Stromboli TTL Titration stand Stromboli TTL 1 Oven temperature [°C] 170 Source for drift Determination Max.start drift [µg/min] 25 012 Mix time Duration[s] 60 013 Titration (KF Coul)[2] Sensor Type Polarized Name DM143-SC Unit mV Indication Voltametric Ipol[µA] 5.0 Stir Speed[%] 40 Control End point [mV] 100.0 Control band [mV] 250.0 Rate Normal Generator current Automatic Termination Type Drift stop relative Drift[µg/min] 10.0 Min.time[s] 30 Max.time[s] 600 014 Calculation R2 Result Content Result unit ppm Formula R2=(ICEQ[2]/10.712-

TIME[2]*DRIFT-B[Blank Stromboli]

Constant C= 1 Decimal places 3 Result limits No Record statistics Yes Extra statistical functions No 015 End of sample


METTLER TOLEDO Application M623-2012 Water Content in Edible Oils and Fats Water content determination by volumetric Karl Fischer titration in edible oils and fats. The sample is dissolved into a methanol:chloroform solvent mixture in order to improve dissolution. The titration is monitored by a double pin platinum redox electrode (voltametric indication).

Preparation and Procedures Caution Use safety goggles, a lab coat and wear gloves. If possible, work in a fume hood. Sample Size: - As there is very little water content in edible oils,

a sample size of at least 1.0 g has to be used to achieve accurate result and a reasonable reproducibility.

Solvent : - Six samples of around 1.0 g could be determined

in 50 mL methanol:chloroform 1:1 (v/v). - After more than six titrations the solubility is

reduced, affecting accuracy and precision. The solvent has to be replaced.

Sampling: - Edible oils:

A 5 mL syringe was used for direct sample input into the titration vessel of approximately 1 g.

- Margarine/edible fats: Water content in margarine is more so sample size taken is 0.1 g. The Visco-Spoon is used to enter margarine into the vessel.

Procedure: - 50 mL dry methanol and Chloroform (1:1) is

added into the titration cell. - The method is started to eliminate all moisture

present in the solvent (pretitration). - A titer determination is performed using di-

sodium tartrate dihydrate as a primary standard. - The sample is added with a syringe. - The sample size is determined by back-weighing. - Margarine sample is taken in Visco-Spoon to

seize weighing error and is dissolved in solvent mixture of chloroform & methanol 1:1.

Remarks

- The KF reagent and the solvent must be protected against intake of air humidity. Drying tubes (ME-23961) filled with molecular sieve and mounted in holders (ME-23915) are used for this purpose.

- The mean value of the titer is automatically stored in the setup data by the function "Titer".

- The concentration of the KF titrant must be set to 5 mol/L since the concentration cannot be entered as mg/mL.

Sample 1 g: ‐ Sunflower oil ‐ Peanut oil ‐ Olive oil ‐ Palm oil ‐ Coconut oil

0.1 g: ‐ Margarine

Compound Water M = 18.01; z = 1

Chemicals Methanol (dry) Chloroform.

Titrant HYDRANAL® - Composite 5 One component KF Reagent

Standard Disodium tartrate dihydrate (C4H4Na2O6·2H2O) M= 230.08, z = 1

Indication DM143-SC (double platinum pin redox electrode)

Chemistry CH3OH + SO2 + 3RN + I2 + H2O →

(RNH)SO4CH3 + 2(RNH)I

Calculation R1 = (VEQ*CONC-(TIME*DRIFT/1000)*C m VEQ: Titrant consumption to EP CONC: Titrant concentration (mg/mL) TIME: Total time since sample

request (min) DRIFT: Air moisture (µg/min) C: 0.1 (Constant for % unit) m: Sample size

Waste disposal

Organic waste

Author, Version

Geeta Naik, IMSG, July 2012 Revised: C. De Caro, MSG AnaChem, July 2012


Instruments - V20/V30 Titrator Note: This application can be also run with T70/T90 in combination with the KF Kit.

- XP205 Balance

Accessories - 1 x 5 mL glass burette DV1005 (MT-51107500) - Visco-Spoon (ME-51107668) - LabX® pro titration software - 5 mL syringe

Results Margarine samples: Results Method-ID Margarine Sample Margarine (1/6) R1 13.406 % Sample Margarine (2/6) R1 13.446 % Sample Margarine (3/6) R1 13.432 % Sample Margarine (4/6) R1 13.433 % Sample Margarine (5/6) R1 13.412 % Sample Margarine (6/6) R1 13.409 % Margarine samples: Statistics Method-ID Margarine R1 6 Samples 6 Mean 13.423 % s 0.016 srel 0.121% Water Content: Comparison of different oils and fats Sample mass n Mean value Std Deviation srel [g] [% water] [% water ] [ % ] -------------------------------------------------------------------------------------- Sunflower oil 0.8500 – 1.2000 6 0.062 0.001 1.960 Peanut oil 0.8500 – 1.2000 6 0.066 0.001 1.258 Olive oil 0.8500 – 1.2000 6 0.078 0.003 3.627 Palm oil 0.8500 – 1.2000 6 0.074 0.001 1.209 Coconut oil 0.8500 – 1.2000 6 0.048 0.002 3.939 Margarine 0.8500 – 1.2000 6 13.423 0.016 0.121

Titration curve

Margarine Sample 3/6


Table of measured values Volume Increment H2O Online drift Signal Change Time

mL mL mg µg/min mV mV s 0.00000 NaN 0.0000 0.0 533.6 NaN 0 0.00000 0.00000 0.0000 0.0 533.7 0.1 0 0.00000 0.00000 0.0000 0.0 534.6 0.9 1 0.00100 0.00100 0.0049 0.0 534.8 0.2 2 0.00625 0.00525 0.0306 97.8 534.3 -0.5 3 0.01525 0.00900 0.0746 458.6 533.9 -0.4 4 0.02825 0.01300 0.1382 1658.3 534.1 0.2 5 0.04550 0.01725 0.2226 2225.7 534.5 0.4 6 0.06650 0.02100 0.3253 2788.3 534.6 0.1 7 0.08900 0.02250 0.4354 3265.2 535.0 0.4 8 0.11775 0.02875 0.5760 3840.0 534.5 -0.5 9 0.15075 0.03300 0.7374 4424.6 534.5 0.0 10 0.18750 0.03675 0.9172 5448.7 533.9 -0.6 11 0.26600 0.07850 1.3012 7729.9 533.7 -0.2 12

---- ---- ---- ---- ---- ---- ---- 3.01000 0.00125 14.7241 581.2 118.0 1.0 78 3.01075 0.00075 14.7278 537.6 107.8 -10.2 79 3.01125 0.00050 14.7303 457.7 114.7 69 80 3.01200 0.00075 14.7339 406.8 109.3 -5.4 81 3.01300 0.00100 14.7388 406.8 111.5 2.2 82 3.01375 0.00075 14.7425 341.5 104.2 -7.3 83 3.01450 0.00075 14.7462 283.3 106.4 2.2 84 3.01525 0.00075 14.7498 276.1 104.8 -1.6 86 3.01675 0.00150 14.7572 290.6 90.7 -14.1 86 3.01775 0.00100 14.7620 290.6 94.3 3.6 88 3.01775 0.00000 14.7620 261.5 94.3 0.0 88 3.01775 0.00000 14.7620 203.4 91.8 -2.5 90 3.01775 0.00000 14.7620 188.9 85.8 -6.0 90 3.01775 0.00000 14.7620 167.1 90.9 5.1 92 3.01775 0.00000 14.7620 138.0 89.2 -1.7 93 3.01775 0.00000 14.7620 116.2 90.8 1.6 94 3.01775 0.00000 14.7620 94.4 92.3 1.5 95 3.01775 0.00000 14.7620 72.6 93.2 0.9 96 3.01775 0.00000 14.7620 29.1 88.9 -4.3 97 3.01775 0.00000 14.7620 0.0 88.9 0.0 98

Comments

• Methanol and chloroform in the ratio 1:1 which do not lead to side reactions with the Karl Fischer reagent.

• To achieve precise results it is necessary to weigh the sample accurately, and in particular, to first clean the syringe with a few mL of sample which are then discarded.

• To ensure a more efficient cleaning, the syringe is gently shaken to allow for absorption of the moisture on the inner wall of the syringe. Subsequently, the syringe is completely filled.

• Disodium tartrate dihydrate is slowly and poorly dissolving in methanol. Therefore, a stirring time of the least 2 minutes is needed to completely dissolve it.

• The solubility of sodium tartrate dihydrate is limited in methanol: in general, it is not possible to perform more than 3 determinations of approx. 50 mg aliquot each within 50 mL of methanol. After three determinations, methanol has to be exchanged.

• Visco-Spoon:


Method

001 Title Type Karl Fischer titration Compatible with T70/T90/V20/V30 ID OIL Title FATS&OIL Author Administrator Date/Time 6/29/2012 3:35:40 Modified at 7/3/2012 Modified by Administrator Protect No SOP None 002 Sample Sample Number of IDs 1 ID 1 __ Entry type Weight Lower limit 0.0 g Upper limit 5.0 g Density 1.0 g/mL Correction factor 1.0 Temperature 25.0°C Autostart Yes Entry After addition Concentration Titrant 1 Nominal Concentration 5 mg/mL Standard Di-Sodium-Tartrate 15.66 Entry type weight Lower limit 0.0 g Upper limit 5.0 g Temperature 25.0°C Mix time 10 s Autostart Yes Entry After addition Lower limit 4.5 mg/mL Upper limit 5.6 mg/mL 003 Titration stand Type KF stand Titration stand KF stand Source for drift Online Max.start drift 25.0 µg/min 004 Mix time Duration 120 s 005 Titration (KF vol) [1] Titrant Titrant KF 1-comp 5 Concentration 5 mol/L Reagent type 1-comp Sensor Type polarised Name DM143-SC Unit mV Indication Voltametric Ipol 24.0 µA Unit mV Temperature acquisition Temperature acquisition No Stir Speed 35% Predispense Mode None Wait time 0 s Control End point 100.0 mV Control band 400.0 mV Dosing rate 5 mL/min Dosing rate 80 µL/min Start Normal Termination Type Drift stop relative Drift 15.0 µg/min At Vmax 5.0 mL Min. time 0 Max. time Infinity Condition condition No

006 Calculation Result Content Result unit % Formula R1= (VEQ*CONC-TIME*(DRIFT/1000))*C/m Constant C=0.1 Decimal places 3 Result limits No Record statistics Yes Extra statistical func. No Send to buffer No Condition No 007 End of sample

This application bulletin represents selected, possible application examples. These have been tested with all possible care in our lab with the analytical instrument mentioned in the bulletin. The experiments were conducted and the resulting data evaluated based on our current state of knowledge.

However, the application bulletin does not absolve you from personally testing its suitability for your intended methods, instruments and purposes. As the use and transfer of an application example are beyond our control, we cannot accept responsibility therefore.

When chemicals and solvents are used, the general safety rules and the directions of the producer must be observed.

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Subjet to technical changes. ©09/2012 Mettler-Toledo AG, Analytical Printed in Switzerland, ME-30057646 Market Support Group AnaChem

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G20 Compact Titrator T70 Excellence Titrator, Rondo30 sample changer and LabX® Titration software.

food and beverages - · pdf filefood and beverages ... titration (or titrimetric analysis) is...

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