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Sun and fun for everyone – SPF determination with UV-VISspectra

The sun protection factor SPF will beone of the most important topics in thenear future.

FAMEs in aviation turbine fuel – a risk?

FAMEs in diesel fuel have an unintended side-effect:Potential contamination of jet turbine fuel!

»Best supporting actor«

HS-20: The new powerful Head-space partner for GC analysisplaying alongside the leadingactors and bringing out the best in them.

Sun and fun for everyone – SPF determination with UV-VIS spectra 2

Practical test: Lead in circuit boards – RoHS II – new guidelines 4

Heavy metals in the food chain –Determination with the high-speed self-reversal method for background compensation 8

Where’s the difference?Volume-based vs. number-based particle size measurement 10

»Best supporting actor« – The new generation headspace sampler 12

Read the lips – FTIR spectros-copy of cosmetics and pharma-ceuticals 14

FAMEs in aviation turbine fuel – a risk? 16

Technical failure or ‘human factor’?Measurement inaccuracies in X-rayfluorescence spectroscopy 19

New accessory for the UV series –Micro cell holder 18

Experimental compartment 6

TOC analyzer in quality control – A customer report from the pharmaceutical industry 11

Global structure – Global Design 20

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SHIMADZU NEWS 1/2013

CONTENT

Sun and fun for eve

Figure 1: Preparation of a sample onto the PMMA polymer plate following recommen-

dations of COLIPA documentation

T he sun protection factor SPFwill be one of the most im-portant topics in the near

future. Due to changes in the glo-bal climate, temperatures andexposure to sun will increase.Humans and animals will be sun-burnt more easily than in the past.

30 years ago a sun blocker with anSPF of 10 was regarded as a highprotection factor. Nowadays, aprotection factor of 50 producedespecially for children is normal.It is difficult to find a reliable pro-cedure for controlling the produc-tion of such mixtures in lotions,milks and creams.

What does SPF stand for?

Sun protection is needed againstexposure through UV-A and UV-B radiation from natural sunlight.

UV-A is by definition the range of380 to approx. 315 nm and UV-Bis the range from 315 down to 280 nm on the wavelength scale.

The target of a cream is to workas a cutoff filter. The exposuretime for the skin is reduced. SPF10 simply means that the treatedskin can stay 10 times longer inthe sun than under normal condi-tions.

The usual sun blockers are oftenprepared with TiO2 which givesthe creams and lotions their whitecolor. TiO2 is a white pigment andby nature an ideal reflector of theradiation. But this is only oneaspect of such complex mixtures.

There is a particular focus on suntransmission which is able to passthe sun blocker film. In principle,

3SHIMADZU NEWS 1/2013

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eryone

guidelines describe a method forthe preparation of samples, simu-lation of the skin, measurementtechnique and analysis of theresults.

30 and 50+ SPF in the spotlight

A PMMA polymer plate simulatesthe skin surface on which 32 mgof cream is distributed. The plate

the sun blocker products can beprepared in a capillary cell withvery low thickness. But the spec-tra resulting from these measure-ments all show different signalstructures, preventing comparisonbased on the SPF factor.

The COLIPA Guidelines define acommon understanding of SPFproducts for all suppliers. The

SPF determination with UV-VIS spectra

surface has a specified roughnessof approx. 5 μm and is suitable for collecting the transmittance of light by UV-VIS spectroscopycombined with an integratingsphere. The measurement pro-cedures are described in the COLIPA method.

This method demands many re-peat measurements and calcula-tions of sum parameters from thedata points of the spectra. Its

mathematical results are the SPFvalue and the critical wavelength.The sample and calculation resultis shown for a material labeledwith SPF 50+. In this example,four measurements were carriedout (shown in Figure 2).

These spectra were entered intothe SPF calculator software andthe result of the SPF 50+ sampleis shown in figure 3.

These simple samples were notirradiated with an UV lamp. Table2 shows a selection of values forall three samples. In table 1 themost important parameters areshown.

Figure 3: SPF calculation for four UV-VIS spectra from a sun blocker defined as SPF 50+,

the graph shows absorbance and transmission spectra, comment lines and inputs required

as well as calculated results

Figure 2: Four UV-VIS spectra of the COLIPA experiment used for each sample:

red was SPF 30, green 50+ and black was a COLIPA Standard (SPF 16), all measurements

performed before exposure

-6.733

290300 350 400

0

20

40

60

80

89

T %

nm

Wavelength Range (nm)Instrument TypeMeasuring ModeSlit Width (nm)

Tabble 1: Measurement parameters for UV-2600 in combination with the ISR-2600 integratingsphere

Table 2: Calculated SPF results from typical UV-VIS spectra of sun crèmes. Calculation

equations are described in the COLIPA document.

Item

290.00 to 400.00UV-2600 SeriesTransmittance5.0

Comment

SPFSPF labelSPF UVA range (320 -400 nm)SPF UVB range (290 -320 nm)Unretained UVA average T %Unretained Short UVA average T %C factorSPF adjustedUVAPF0Critical lambda (pre-irradiation)

63.1260

46.77

66.82

8.16

2.23

0.98850

30.33379 nm

30.6930

18.49

34.24

18.55

5.46

0.99330

10.93372 nm

18.8616

19.35

18.79

12.23

4.94

0.94416

14.78380 nm

SPF characteristics Calculated valuesLabel 60 Label 30 Standard

Conclusion

The UV-VIS-spectrophotometerUV-2600 combined with ISR-2600integrating sphere is ideal for thisapplication: the same system ana-lyzes the color of the sun cream aswell as the packaging. The samplesmeasured here are labeled withSPF 30 and SPF 50+, difficult tomeasure with older technologiesbut easy with the UV-2600 spec-trophotometer.

Literature[1] In vitro method for the determination

of the UVA protection factor and “critical wavelength” values of sun-screen products, COLIPA Guidelines,March 2011

APPLICATION

4 SHIMADZU NEWS 1/2013

U p to now, lead constitutedabout 60 percent by weightas a component in solders,

used in the manufacture of circuitboards for electrical and electronic

Practical test: Lead in circuiICP-OES spectroscopy – RoHS II – new guidelines

On this occasion, a test was car-ried out to determine the presenceof lead in solders used in variouscircuit boards (Figure 1) in electri-cal and electronic equipment.Shimadzu’s ICPE-9000 emissionspectrometer with inductivelycoupled plasma was used for thisinvestigation (Figure 2).

In addition to lead, other elementscan be determined simultaneouslyin a single measurement using theICPE-9000, which provides awealth of information on a givensample within a very short time.The emission of sample atoms inthe wavelength range of 167 nm to 800 nm is separated within anevacuated spectrophotometer anddetected using a large high-resolu-tion CCD chip. Due to the vacu-um, the spectrometer of ICPE-9000 does not have to be flushedwith inert gas and additional aminitorch reduces operation costssignificant because of its low ar-gon consumption rate of 10 L/minwhich is sufficient for stable oper-ation of the analytical plasma.

Figure 1: Electronic circuit boards – examples of sample material

equipment. Under the RoHSdirective, the continued use ofthese solders is now only allowedin exceptional cases, so substitu-tion products are on the increase.

Figure 2: ICPE-9000 simultaneous ICP-OES spectrometer with low operating costs


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lematic in terms of RoHS II. Thisillustrates the importance of clari-fication of vague definitions (seeinfo box) such as, for the sourcematerial, 'homogeneous material':A “material of uniform composi-tion throughout or a material,consisting of a combination ofmaterials, that cannot be disjoint-ed or separated into differentmaterials by mechanical actionssuch as unscrewing, cutting,crushing, grinding and abrasive

racy of the results, the analyticalemission lines used for evaluationwere examined in detail withrespect to interference influences.As an example, emission profilesof the lead calibration are shownin figure 3.

Results

One can reasonably expect thathigh lead content is due to severalsmall contamination sources suchas soldered joints. Since the resultswere based on total solder massincluding plastic materials, the‘undiluted’ contamination sourcescould exhibit an even higher leadconcentration, making the use ofthese products even more prob-

processes.” [1] In this way, noteven a single soldered joint mayexceed the limit value if the distri-bution of an electrical or electron-ic equipment to and withinEurope is to be further main-tained.

References[1] http://eur-lex.europa.eu/LexUriServ/

LexUriServ.do?uri=OJ:L:2011:174:0088:110:DE:PDF

Prior to measurement, a suitablesample preparation procedure isrequired to convert the heteroge-neous circuit boards into liquidhomogeneous samples. For thispurpose, each circuit board isground using various mills into afine powder which is subsequent-ly acid-digested in a microwavesample preparation system.

The prepared sample can now bemeasured directly. To ensure accu-

t boards

Hazardous substances ban for electrical and electronic equipment

RoHS stands for Restriction of Hazardous Substances and regu-lates the use of certain hazardous substances in electrical and elec-tronic equipment, namely lead, mercury, cadmium, chromium VIand two special brominated flame-retardants.

While the first RoHS directive (2002/95/EG) has been in forcesince 1 June 2006, its successor directive RoHS II (2011/65/EU) [1] applies as of January 2013. Despite discussions on changing oflimit values or inclusion of additional elements, the original valuesremain in force. For instance, the limit value for lead remainsunchanged at 0.1 percent by weight. However, variations in thescope of the instruments types have been taken into consideration.Recently, medical devices or monitoring and control instrumentsare also covered under the directive.

In addition, vague terms have been defined in more detail, such as the scope of parties responsible in the product chain as opposedto just the ‘manufacturer’ in RoHS-I.

Figure 3: Emission profiles of the calibration for lead at 220.353 nm (left) and a possible

source of the lead: Solder to attach electrical components to electric circuit boards (right).

125

150

175

200

225

250

275

300

325

350

375

400

Inte

nsit

y

ABCDEFG

30.341.1

8.4711.90.616

34.946.4

Table 1: Lead content of the electrical

circuit boards

Sample Pb [g/kg]

LATEST NEWS

A lthough pharmacy is one ofthe oldest academic disci-plines, it is in its present

form a relatively young science. In today’s pharmaceutical sci-ences, drug and active ingredientdevelopment is focused on ensur-ing that only specific substancesunfold their effects followingmedication – side effects causedby interfering substances andimpurities are undesirable. Forthis reason it is important to usethe purest possible substances andpurified tools and materials in theproduction of pharmaceuticals.

To ensure that equipment is freefrom undesirable foreign sub-stances, cleaning of instrumentsurfaces is validated using variousmethods. For instance, the finalrinse water after a cleaning pro-cess can be analyzed for possiblecontaminations. Likewise, a mate-rial surface can be wiped with asuitable medium and subsequentlybe analyzed for possible impuri-ties.

Various parameters are used forsuch analyses. TOC (Total Or-ganic Carbon) is one of the mostinformative analytical methods.The TOC parameter is a measureof organic contamination in amatrix.

TOC – the dirt trap

The TOC is an excellent analyticalparameter to indicate and ensurethat the instruments are free fromtraces of ‘previous’ drug batches.The TOC not only mirrors thepresence of drugs, but also indi-cates other contaminants such asthose originating from cleaningagents.

TOC determination is carried outvia oxidation of the organic com-pounds to carbon dioxide. Thecarbon dioxide is subsequentlytransferred to an NDIR detectorand measured. Oxidation is car-ried out in various ways – either

organic compound and, therefore,also to evaporated or sublimatedorganic compounds. On the otherhand, the earlier study alreadyimplied the first experimental con-firmation of this assumption.

Experimental setup:the compartment

Recently, a simple experimentusing camphor, water and air in aclosed container has been repeat-ed: the metal relic of the pastmeasured 700 x 360 x 380 mm (L x W x H) and the total volumewas approximately 97 liter. A beak-er containing 1 g of solid camphor(melting point 179.75 °C) wasplaced in the center of this metalbox. Two beakers, each containing50 mL of ultrapure water, wereplaced symmetrically in the centeron either side of the camphorbeaker. Two stainless steel trays,each with dry surface measuring250 cm2, were placed on eitherside of the three beakers.

Questions needing to be verifiedexperimentally over an appropri-ate time period were:• Can camphor be detected

following sublimation and diffusion?

• Does diffusion take place in thewater medium?

• Is the stainless steel surfaceimpinged by camphor?

The box was closed with a cover,and this experimental setup withinthe airtight container was left atroom temperature for 14 days.

On first opening, 1 mL of theinner air was withdrawn using agastight syringe and analyzed forcamphor using direct-injection gaschromatography. The water in thetwo beakers was analyzed sepa-rately for TOC content. In addi-

tion is given in the context thataqueous rinsing solutions afterbeing in contact with air, may nolonger comply with the TOClimit values for purified water.This is to be expected in terms ofphysics and subject to the laws ofFick, Dalton and Henry.

Simply stated: mobile compoundsdiffuse into media and betweenmedia such as air and water untilthey reach uniform distribution(Fick’s laws). In closed systems,for instance in an air compart-ment, the total pressure is the sumof the partial pressures (Dalton’slaw). If a water surface is presentin the air compartment, the gas-eous molecular compounds dif-fuse into the water phase accord-ing to their partial pressures(Henry’s law).

This represents the physics interms of the model for ‘idealgases.’ From another point ofview, it could be that these lawsapply to every airborne, molecular

via chemical reaction of the organ-ic compounds in the presence ofsodium persulfate under UV irra-diation, or via catalytic combus-tion at 680 °C.

Cleaned surfaces are, however, notpermanently cleaned and then us-able at all times. They can be con-taminated again through variousenvironmental influences. Thisalso applied to the rinsing water.When carrying out cleaning vali-dation, it is important to takethese environmental influencesinto account.

Organic compounds diffuse into water

A simple experiment carried outin a previous study has shownthat the carbon content of water(Total Organic Carbon, TOC)that is in contact with air increasestime-dependently. It was conclud-ed that airborne, molecular organ-ic compounds diffuse into water.The relevance to cleaning valida-


Experimental compart-mentCleaning validation, Henry’s law and diffusion associatedwith airborne molecular contamination

Figure 1: Experimental setup before and after closing the compartment


LATEST NEWS

tion, camphor was determined viaUV spectrophotometry. The sur-faces of the stainless steel trayswere rinsed with methanol andcamphor was determined via UVspectrophotometry.

Results

The results were as follows:

• Camphor could be detectedusing gas chromatography asbeing present in the closed aircompartment as an airborne,molecular organic compound.

• Camphor was detected in watervia UV spectrophotometry.

• The measured TOC content inboth water samples was consis-tently found to be 400 ppm and399 ppm.

• Camphor could not be detectedat the trace level on the stainlesssteel surfaces using UV spec-trophotometry.

An initial interpretation was asfollows:

• As expected, camphor subli-mates at room temperature andis distributed evenly in the aircompartment in the form of air-borne molecular organic gas(Fick’s law).

• According to Henry’s law,molecular gas-phase camphordiffuses into the water.

• The airborne camphor moleculescannot diffuse into the metal lat-tice of the stainless steel traysand ‘wander’ through the latticeimperfections like ions accord-ing to Henry’s law. In this ex-periment, the reactivity of thesurfaces and the other thermo-dynamic boundary conditions ofthe experiment did not lead toresublimation of gaseous cam-phor or solidification of UV-active degradation and reactionproducts on the stainless steelsurfaces.

Relevance for cleaning validation

The above represents the physicsaspect with the anticipated results.

cal detectability. The idea that airand cleaned surfaces are ‘clean’ inthe sense of ‘free from foreign sub-stances’ should clearly be aban-doned.

Authors

Dr. Wolfgang Woiwode TECHPharm GmbH www.techpharm.de

Sascha HupachShimadzu Deutschland GmbH www.shimadzu.de/home

Note: The experiments describedabove have been carried out byTECHPharm GmbH, Bruchsal, Germany.

tion and solidification, wherebycondensed water with its estab-lished phase transitions inaccordance with Henry’s lawcan also act as a medium and‘vehicle.’

The relationships and considera-tions mentioned here can be usedin the substantiation of expectedvalues and acceptance criteria, aswell as for the determination ofthe shelf life of cleaned and driedstainless steel equipment. As alimitation, it should be pointedout that in production plants, notonly airborne molecular contami-nation but also airborne particularcontamination must always betaken into account. Due to masstransport, particular contamina-tion is even more relevant thanairborne molecular contamination.

Conclusion

In the simple experiment de-scribed, the phase transitions solidphase ––> gas phase ––> waterphase were verified using camphoras an example.

With respect to the integrity offormulations and equipment sur-faces in contact with air duringpharmaceutical production, atleast several hundred known phar-maceutical raw materials and sev-eral thousand additional organicscan be potential molecular air-borne contaminants of the phar-maceutical products. Subsequentreactions of the airborne contami-nants – taking place in the air,with atmospheric oxygen, watermolecules, via catalysis on metalsurfaces and finally also in contactwith particles – seems hardlycomprehensible in terms of num-bers.

It is reassuring that all of this hasnot, so far, presented any signifi-cant limitation in the developmentof pharmaceutical productionprocesses. Contaminants as wellas contaminants resulting fromsubsequent secondary reactionsare, in many cases, already presentat levels below any perception anddetection capabilities. In excep-tional cases however, contami-nants that have reached a productvia diffusion, have already led tocomplaints of an organolepticnature without any direct analyti-

What is the relevance of this sim-ple experiment for cleaning valida-tion? Here are the conclusions:

1. Solids sublimate depending ontheir vapor pressure and, fromthe perspective of cleaning vali-dation, become airborne molec-ular contaminants (AMC).

2. In principle, diffusion of gas-eous molecular substances in-cluding organic contaminantstakes place in the air and inadjacent media such as waterand solids. Substances andorganics can turn into airbornemolecular contaminants, evenwhen they are stored furtherapart.

3. When purified water is used forrinsing, its carbon content canincrease due to diffusion of air-borne molecular organic con-taminants. Exceeding the limitvalues of 500 μg C/L is thenonly dependent on the durationof air contact and the dimensionof the water surface that is incontact with air.

4. When purified water is used forrinsing, its conductivity increas-es due to diffusion of carbondioxide. Exceeding of the limitvalue of 5.1 μS/cm at 25 °C bythe secondary product carbondioxide depends on the dura-tion of air contact and the di-mension of the water surface incontact with air. This analogousconclusion, which has been ex-perimentally verified elsewhere,is mentioned here for the sakeof completeness.

5. In the present experiment, sub-limation of gaseous camphorwas not detected on the stain-less steel surfaces after 14 daysat room temperature.

6. Conclusion 5th results do notrule out that secondary reac-tions can be initiated by reac-tive surfaces, contaminants andgaseous water (‘humidity’) andcause the formation of depositswith further solidification.

7. The results according to con-clusion 5 do not rule out thattemperature differences cancause the formation of solids(‘depositions’) due to condensa-

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PublisherShimadzu Europa GmbHAlbert-Hahn-Str. 6 -10 · D-47269 DuisburgPhone: +49 - 203 - 76 87-0 Fax: +49 - 203 - 76 66 [email protected]

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Design and Productionm/e brand communication GmbH GWADüsseldorf

Circulation German: 5,090 · English: 16,390

CopyrightShimadzu Europa GmbH, Duisburg,Germany – April 2013.

Windows is a trademark of Microsoft Corporation. ©2013

Apple Inc. All rights reserved. Apple, theApple logo, Mac, Mac OS and Macintoshare trademarks of Apple Inc.

APPLICATION

H eavy metals such as cadmi-um, chromium and lead arenatural components of the

earth’s crust and are typicallypresent in our environment inhigher or lower concentration lev-els. They enter the human bodyvia food, drink and air. Some ofthese heavy metals, so-called traceelements such as Chromium, Iron,Cobalt, Copper, Manganese, Zincand Tin are essential in low con-centration levels to the humanbody, as they are important forthe metabolism. However, at high-er concentrations they are harmfuland poisonous to the human body.

ly, control of elements at trace andultra-trace concentration levels iscarried out using atomic absorp-tion spectrometers such as theShimadzu AA-7000. This fullyautomatic double beam dualatomizer system is equipped withthe GFA-7000 graphite furnacefeaturing digital control, and theASC-7000 sample preparation sta-tion (see figure 1).

The AA-7000 concept allows fullyautomatic changeover from flameto graphite furnace mode and ele-ment-specific optimization of theatomizer position. The systemincludes two methods of back-ground correction for the deter-mination of heavy metals in sam-ples of complex matrices whenusing flame and graphite furnaceatomization. The Deuteriumbackground correction is usefulfor compensation of spectralinterferences generated by molec-ular absorption and particulate-caused scattering. In addition, thehigh-speed self-reversal technique(high current pulse technique) isuseful for compensation of inter-ferences caused by overlappingabsorption lines and structuredbackground.

All drinking water and wastewateris monitored continuously accord-ing to the European drinkingwater regulation and the law forindirect introduction of waste-waters. In addition, food is con-trolled through the German food-stuffs and requirements law wherethe determination of heavy metalssuch as lead and cadmium isstrictly controlled in § 35 LMBGL00.00-19/3.

Determination of Cadmium infood and soil samples

High concentrations of Cadmiumin contaminated soils can be dan-

Typical heavy metal poisoning iscaused by drinking water contam-ination from lead pipes, air con-tamination from industrial emis-sion sources, or intake via thefood chain in the form of contam-inated vegetables, meats and fish.

Cadmium in drinking water

Water for human consumption hasto fulfil the European drinkingwater regulation, where the maxi-mum allowable concentration lev-els of the essential and toxic ele-ments are clearly defined. Typical-


Heavy metals in the food chainDetermination with the high-speed self-reversal methodfor background compensation


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Figure 1: Fully automatic atomic absorption spectrometer AA-7000

Wavelength [nm]Slit width [nm]AtomizationLamp current D2 BGC* [mA]Lamp current SR BGC* [mA]Atomization temperature [°C]

Table 1: Instrumental parameters for determination of cadmium with different background

compensation methods

Element

228.80.7

Graphite furnace– –

10/1002100

Cd

228.80.7

Graphite furnace8

– –2100

Cd

gerous as it can enter the foodchain through plants. Accordingto the European food safetyauthority, foodstuffs are the mainsource of cadmium exposure forthe non-smoking general popula-tion [1]. The types of food con-tributing for the major part todietary cadmium exposure, prima-rily due to high consumption, arecereals and cereal products, vege-tables, nuts and potatoes as well as meat and meat products. Highcadmium concentrations are ex-pected in vegetables grown onsoils close to industrial areas suchas smelters.

In order to analyze food and soilsamples, the analytical procedurebegins with sample digestionusing a microwave digestion sys-

tem with a typical sample weightof approximately 250 mg in a mix-ture of 1.5 mL nitric acid (70 %)and 4.5 mL sulfuric acid (70 %).The sample solutions are trans-ferred into a 10 mL flask and filledup to volume accurately. Quan-titative determination of cadmiumis done using a fully automaticsequence programmed on AA-7000, with a calibration curvefrom a stock standard solutionwith matrix matched acid concen-tration using the ASC-7000 sam-ple preparation station in combi-nation with the autodiluter.

Table 1 shows the instrumentalparameters using conventionalhollow cathode lamps and the rec-ommended currents for low andhigh current measuring mode

using the high speed self reversalmethod which has been selectedbecause of the complex matrix.The high-speed self-reversalmethod is able to compensate forspectral interferences caused byhigh iron concentrations on thecadmium line. Even arsenic inter-ferences are also compensated for.

To apply the technique of thehigh-speed self-reversal back-ground compensation, the cadmi-um hollow cathode lamp currentis modulated in two modes. In thelow current mode at 10 mA, ab-sorption of element and back-ground signals is measured whilein the high current mode at 100mA only the background signal isdetected. Because the high currentmode determines only the back-ground absorption, the differencebetween the absorption of bothtypes of light provides accuratebackground compensation andmeasurement of the atomic ab-sorption of the target element.Further experimental work oncadmium determination in heavymatrix samples has been publishedby Waterlot and Douay [2].

Summary

Fully automatic atomic absorptionspectrometers such as the AA-7000 are the right tools for solvinga wide range of application prob-lems in environmental and foodanalysis. Since the list of contami-nants and their maximum contam-inant level is expected to be evenmore stringently controlled infuture, there is a real need for sys-tem configurations with lowestdetection limits and highest preci-sion. Shimadzu offers total hard-ware and software solutions foraccurate determination of contam-inants in water, food and soil sam-ples, demonstrating competenceand know-how of a market leaderin spectroscopy.

References[1] http://www.efsa.europa.eu/en/efsajournal/

pub/980.htm

[2] Christophe Waterlot and Francis Douay,

Talanta 80 (2009) 716 -722

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S himadzu offers a broad vari-ety of particle size instru-ments, which support the

well-established laser diffractionmethod, able to cover the meas-urement range of 0.5 nm to 3,000μm. Additionally and exclusivelyShimadzu offers the patented in-duced grating method.

A wide range of accessories en-ables measurements of highly con-centrated, dry or small-volumesamples. The phrases “volumebased particle size distributions”and “number based particle sizedistributions” often appear whendiscussing the results of particlesize measurements.

What is the difference between number and volume based result?

When looking at particle size dis-tributions, “number-based” and“volume-based” change the scal-ing of the y-axis. If not explicitlymentioned, the scaling is “volume-based” as it is the more typicalscaling. But “number-based” isalso quite common.

Here’s the difference: Let’s assumethat a sample solution containsparticles with an average radius of50 μm respectively 100 μm. Theratio of these particles is 1:1.

Dividing 4188790 by 523598 re-sults in 8. So 1:8 is the ratio of thepeaks at 50 μm and 100 μm in theexample above.

In the analysis of an unknownsample containing larger andsmaller particles and “volume-based” analysis is chosen, it ispossible that the peak at lowerparticle sizes cannot be seen. Onthe other hand, it is much easierwhen reporting with a number-based scaling to find the smallestparticles of the sample solution.

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When looking at “number-based”results two peaks will appear: Onepeak is at 50 μm and the second at100 μm. The ratio of these peaks is1:1.

When changing to a “volume-based scaling” the ratio of thesepeaks changes to a ratio of 1:8.The peak at 100 μm is now eighttimes larger in comparison to thepeak at 50 μm.

Here’s the explanation

When looking at number-basedresults, the number of particles istaken into account. At a mixtureof 1:1, the intensity of the lines isself-explanatory.

When looking at volume-basedresults, the volume of the particlesis considered. The software im-plies that all particles are spheresand calculates their volumes ac-cording to

Using particles with 50 μm and100 μm radii (1:1 mixture) resultsin following equations:


Where’s the difference?Volume-based vs. number-based particle size measurement

Figure 1: Number-based particle size measurement

Inte

nsit

y

Particle diameter

Number-based

1 :1

50 μm 100 μm

Figure 2: Volume-based particle size measurement

Inte

nsit

yParticle diameter

Volume-based

1 :8

50 μm 100 μm


LATEST NEWS

T illotts Pharma AG in Rhein-felden, Switzerland has in-stalled a Shimadzu TOC-L

analyzer for their quality control.The company produces and mar-kets pharmaceutical products,medical devices and diagnostics forfocused gastroenterological treat-ments and applications. In their“Tillotts Newsletter, issue 6” theydescribe applications and theirexperiences with the TOC analyz-er.

In July 2011 a new TOC analyzerwas installed and qualified in Qua-lity Control. This equipment isused for measuring the Total Or-ganic Carbon (TOC) content inliquid, solid or gaseous samples. Itcan be used in many applicationsfor example cleaning validations, toverify the effectiveness of cleaningprocedures and analysing the puri-ty of different water qualities e.g.waste water, drinking water andwater for pharmaceutical use.

The TOC content is a very impor-tant sum parameter and imple-mented in many monographs in allpharmacopoeias. The TOC analy-sis is an unspecific method deter-mining all organic components thatcan be oxidised to carbon dioxide(CO2) which is determined quanti-tatively and very precisely by IRabsorption. The advantage is thatall components are measured inone run and that even unknowncompounds like impurities are cap-tured. In contrast other methodslike chromatography (HPLC) orspectroscopy (UV, IR) detect andquantify a specific component onlylike the active substance (e.g. me-beverine hydrochloride) or a clean-ing agent.

There are two different kinds ofpreparation methods: the wetchemical oxidation and the com-bustion catalytic oxidation meth-od. The commercially availableTOC analyzers all have very widemeasuring ranges over several de-cades of e.g. 4 μg/L up to 30,000

equipment that is also quite robust;after some initial trials we are nowfamiliar with its routine use. It hasa wide measuring range and theanalysis can be performed veryquickly with high precision. Thehandling of the TOC system(equipment and software) is easy,so an effective and efficient work-ing is possible.

“Last but not least, we choseShimadzu because of having a part-ner with great experience and reli-able service not only in TOCanalysis but other analytical tech-niques (IR, UV) that gives supportin technical aspects, methods andqualification. We have a servicecontract in place like for other ana-lytical equipment.”

Automatic sample acidifica-tion/spargingAutomatic dilution function: if the TOC content is too high fordirect measuring

*ppm = parts per million (10-6),ppb = parts per billion (10-9)

Conclusion The new TOC-LCPH analyzer ofShimadzu was installed and quali-fied without problems. It was usedsince then in cleaning validations(showing in three runs the validityof the general cleaning procedure)and in the verification of a singlecleaning procedure e.g. after thecustom manufacturing of capsulesfor a clinical trial where only onebatch of placebo and verum wereproduced. Here, the result of thecleaning is available on the nextday and enables a quick decisionwhether a second cleaning is neces-sary or not and therefore avoidinglong times of cessation in produc-tion. It is a very useful piece of

mg/L for the actual type TOC-LCPH of Shimadzu. This is facili-tated by diluting the sample solu-tion. The calibration of the analyti-cal method is done by means of astandard solution with a certifiedcontent of organic carbon of 1,000mg/L. Of course, an SST (systemsuitability test) is performed withtwo independent references (ben-zoquinone, saccharose) to showthe proper function of the wholesystem.

Summary description of the TOC analyzer in QC

Model: Shimadzu TOC-LCPH(see figure 1)Type: combustion type analyzerSoftware: compliant to 21 CFRPart 11 (FDA) – Use of normal orsensitive catalyst, analyzing downto a limit of detection in ppm toppb range*

Autosampler ASI-L: for effectiveand efficient working

TOC analyzer in quality controlA customer report from the pharmaceutical industry

Figure 1: TOC-L

T he Tony awards, the Goyaor Molière prizes, Polish orGerman Film prizes, Acad-

emy awards, Golden Globeawards or the César – they allaward prizes for best supportingactors or actresses playing along-side the leading actors and bring-ing out the best in them. And notjust human actors but also robots,such as R2D2 or cars (‘Herbie’)can shine in supporting roles.

What is true for theatre and filmalso applies to technology: in ana-lytical instrumentation, the lead-ing systems unfold even more of their full potential when pairedwith high-quality peripheral sys-tems. A new actor on the analyti-cal scene is the HS-20 headspaceautosampler, supporting GCanalysis (Figure 1).

In headspace analysis, samples aretypically heated in 10 - 20 mL gas-tight sample vials. Depending onthe nature of the sample (matrix),volatile substances diffuse into thegas phase. When a defined volumeof this gas phase is withdrawn andsubsequently injected into a gaschromatograph, the results allowconclusions to be drawn on thecomposition of the actual sample.

Automation included

Another advantage of HS versussample extraction is its completeautomation, in which modern HSautosamplers enable highly com-plex and very detailed and con-trollable sample preparation. Asthe gaseous sample comes intocontact with a variety of surfacesin the autosampler’s sampling sys-tem, deactivation of these surfacesis essential in order to meet thehigh analytical demands of traceanalysis.

The HS-20 headspace sampler setsnew standards in meeting of thesedemands. Designed as ‘transferline HS system’ it complementsthe syringe-based HS AOC-5000Plus sampler. While the latterallows a flexible choice of injec-tion techniques (liquid, headspace,solid-phase micro-extraction[SPME] and in-tube extraction[ITEX]), the HS-20 is firmly con-nected to the GC system via atransfer line, offering better preci-sion and more headspace analysisoptions.

A large incubation oven allowssimultaneous sample preparationof up to twelve samples. It is fur-nished with a sample tray holding90 samples (Figure 3), where 10and 20 mL HS sample vials, screwor crimp vials can be placed in anyorder. For rapid gas phase equili-bration, the samples are shakenduring incubation. The incubationtemperature of the oven can be setto up to 300 °C and kept constantusing an air circulation system(similar to a GC oven). An incu-bation time of up to 1,000 minutesis possible.

Excellent recovery rates and reproducibility

The inert transfer line, optimizedfor connection to Shimadzu’s GC-2010 series, enables transfer of high molecular weight as well assurface-active substances to theGC system with superior recoveryrates and reproducibility (Figures4 and 5). All lines in the HS-20with direct sample contact can beheated up to 300 °C – the transferline optimized for the GC-2010can be heated to 350 °C. This en-ables a 100 % recovery rate for theusual test with n-alkanes up to C24.

tween the liquid or solid and thegas phase is essentially influencedby the incubation temperature andthe matrix, i.e. the chemical com-position of the liquid or solidphase (Figure 2).

Headspace techniques (HS) areespecially popular for samples thatcannot be measured via gas chro-matography without prior samplepreparation. Examples are tracesof organic compounds on solids,for instance fire accelerants onbuilding components, or odor-intensive substances in plastics,residual solvents in drugs, but alsodrinking water.

Large sample volumes for trace analysis

The great advantage of HS lies inthe available sample volume ofseveral milliliters. Whereas in con-ventional liquid injection only afew microliters of a sample can beevaporated, a much higher samplevolume is available in HS analysis.With virtually quantitative diffu-sion of volatile substances fromthe sample volume into the gasphase upon heating, HS allowsinjection of significantly more ofthe substance amount comparedto the volume possible via liquidinjection of the same sample.

In this way, headspace analysiscan significantly decrease detec-tion limits. The concentrationequilibrium of a component be-

»Best supporting actor«HS-20 – The new generation headspace sampler

APPLICATION


Figure 1: HS-20 headspace autosampler with the GC-2010 Plus

Figure 2: Phase equilibria in the

headspace vial

Figure 4: HS-20 reproducibility for methanol in water

0.0

1,775 1,800 1,825 1,850 1,875 1,900 1,925 1,950 1,975 2,000 min.

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

uV (x 100,000)

But beyond this, the HS-20 setsnew standards as evidenced by therecovery rates of over 50 % for n-C32. Further proof of the inert-ness of the HS-20 is the very lowcarry-over rate for surface-activesubstances, for instance a carry-over of less than 0.0001 % for 1,3-dimethyl-2-imidazolidinone(DMI) and for acetic acid.

The HS-20 offers a ‘multipleheadspace extraction’ (MHE)function for detection of matrixeffects or quantification of volatilecomponents in solids (i.e. plas-tics). Up to 10 headspace extrac-tions per vial are possible. Volatilecomponents can be quantifiedfrom the decrease of the peakareas from extraction to extrac-tion. Essential here is constantpressurization of the vials. Priorto each measurement, the samplevial is pressurized to a predeter-mined pressure using an inert gas,


APPLICATION

Figure 6: Results of the internal HS-20 diag-

nostics. Comparing the ‘maximum pressure’

immediately following pressurization to the

‘minimum pressure’ after a set waiting period

for reaching equilibrium does not reveal any

difference. This demonstrates that the vial

was closed properly.

Figure 5: HS-20 recovery rates as a function of incubator temperature

0.0C12 C16 C20 C24 C28 C30 C32 C36 C40

300 °C

1.20

0.20

0.40

0.60

0.80

1.00200 °C

Figure 3: Air circulation incubator oven and sample tray of the HS-20

essential to attain accurate resultsin MHE – and also a factor forgood reproducibility in conven-tional HS analysis. For pressuriza-tion, the HS-20 uses the provenelectronic pneumatics of the GC-2010.

Casting – the optimal cast list

The HS-20 is available in severalversions. In addition to the stan-dard model, a ‘HS-20 Trap’ ver-sion is also available. This modelallows enrichment of multipleextractions from one sample vialonto a cold trap filled with anadsorbent (e.g. Tenax TA) for thedetection of low trace amounts.The trap is cooled down to -30 °Cusing a Peltier element, whichenables freezing of the multipleextracts obtained from one samplevial and subsequent focused trans-fer onto the separation column via

rapid heating. Using repeatedextraction, the amount of sampleused in the analysis can be signifi-cantly increased, opening up newpossibilities especially for traceanalysis.

The software directs the analysis

The HS-20 can be controlled easi-ly via the supplied software. Alter-natively, drivers can be integratedwithin the GC software packages(for instance LabSolution). In thiscase all parameters of the auto-sampler method, along with theGC method, are stored in thechromatogram data file and can beviewed at any time. At the sametime, internal diagnostic results ofthe sampler are also retrievable,for example when checking wheth-er a vial has maintained pressureafter pressurization or whether ithas been closed properly (Figure 6).Used in combination withShimadzu’s GC and GCMS sys-tems, the HS-20 trap system signi-fies the start of a new era in head-space trace analysis.

the instrument. Compared toother techniques, ATR eliminatesmost of the sample handling timerequired. In most cases, a samplecan simply be dispensed to theATR crystal and detection canstart without any further prepara-tion. In this context, the diamond-equipped ATR version is usefulsince the high pH-value of manycreams can attack the convention-

APPLICATION

C osmetics and perfumes areoffered as powders, liquids,creams and emulsions. Some

products and their functions over-lap with medical substances.

Infrared spectroscopy is an ana-lytical tool which differentiatesbetween them, both cosmetics andtoiletries as well as medicinal in-gredients.

One part of the human bodyneeds special care – the lips. Theyare very sensitive towards envi-ronmental influences, for exampleexposure to the sun, food or vi-ruses such as herpes. These allaffect the lips and can cause pain-ful reactions. This article focuseson lip balm, available as cream orbalsam.

Special care for lips

In the dry atmosphere indoorsduring the winter, lips tend todehydrate and need special care.The same effect occurs in sunlight

in diameter) of the single reflec-tion ATR unit. The accessory usedis based on the diamond window.

FTIR methods applied

FTIR spectroscopy is a powerfultool which can be applied to awide range of sample types. Themajority of the samples can beread using an ATR accessory inin winter or summer. Under these

conditions, water in a lip cream isunhealthy. Instead, a fatty productis needed for protection of the lipsin order to avoid sunburn. Par-ticularly in snow-covered moun-tains regions the burn effect iseven more dangerous and the lipsdemand care products with ahigher proportion of fat with UVfilters.

Medical creams are independentof this subject. Their role is totransport embedded medicine intothe lips to stop or avoid the ap-pearance of diseases such as her-pes (herpes labialis).

In order to demonstrate the sim-ple differences between pharma-ceutical and cosmetical ingredi-ents, some lip creams were meas-ured using FTIR spectroscopyequipped with a single ATR(Attenuated Total Reflectance)accessory. Small portions of bal-sam and creams were placed onthe measurement window (2 mm


Read the lipsFTIR spectroscopy of cosmetics and pharmaceuticals

Figure 1: Four different infrared reflection spectra from diverse lip balsams and

creams: black shows lip balsam, green a UV protection lip cream, blue a medicine

against herpes while the red line shows a pharmaceutical lip cream containing

dexpanthenol and ceramides.

%

1/cmLip balsam based on beewachs – Pfleger

20

4200

26323844505662687480

9286

98104

3600 3000 2400 1900 1600 1300 1000 750 500

%

1/cmUV protection lip cream – Walther Sc

20

4200

26323844505662687480

9286

98104

3600 3000 2400 1900 1600 1300 1000 750 500

%

1/cmAciclovir AL Creme – Aliud Pharma

20

4200

26323844505662687480

9286

98104

3600 3000 2400 1900 1600 1300 1000 750 500

%

1/cmBepanthol lip cream – Bayer

20

4200

26323844505662687480

9286

98104

3600 3000 2400 1900 1600 1300 1000 750 500


APPLICATION

al ZnSe crystal normally used inthe ATR accessory.

Samples were applied directly tothe measurement window. Fordata acquisition, default resolutionwas used with wavenumber ranges4,000 - 400 cm-1, Happ-GenzelApodization and 4 cm-1 resolutionwith an accumulation of 40 scansfor the signal averaging (multiplexadvantage of the FTIR technique).

The benefit which ATR providesis excellent throughput and per-formance - combined withShimadzu’s FTIR Spectrophoto-meter with exceptionally highthroughput of light and very highsignal-to-noise ratio. Introducinga liquid or powder sample to theaccessory simply requires dispens-ing the material into the smallmeasurement window.

Figure 2: Comparison of the lip balsam with a rape seed oil spectrum. The peaks in the

spectra mainly belong to the fatty acid molecular groups.

1/cmLip balsam based on beewachs – Pfleger

-0

0.15

0.30

0.45

0.60

0.75

0.90

1.05

4500 4200 3900 3600 3300 3000 2700 2400 2100 1900 1750 1600 1450 1300 1150 1000 850 700 550 400

1/cm100 % rape oil, 99 g fat (6 saturated fatty acid, 64 single unsat, 29 multiple unsat)

-0

0.15

0.30

0.45

0.60

0.75

0.90

1.05

4500 4200 3900 3600 3300 3000 2700 2400 2100 1900 1750 1600 1450 1300 1150 1000 850 700 550 400

Abs

Abs

Figure 3: The chemical structure of Acyclovir, by name 2-Amino-9-(2-hydroxyethoxymethyl)-

3H-purin-6-on.

Figure 4: Structures of Ceramide (above) and Dexpanthanol (below); above the typical

structure of a ceramide is shown whereas R equates to a fatty acid.

The spectra of balsam and creams

According to the label, the lip bal-sam is a mixture of detergentsblended with beeswax. A librarysearch connects the spectrum tofat, oils and waxes. It shows thetypical fatty acid signal at 1,740cm-1.

The lipstick with UV protectionand the balsam are reduced in themain spectrum to fat, oils andwax. The balsam spectrum con-tains more infrared informationwhich seems to be of inorganicmaterial, most probably TiO2 orsome other salt as the cream iswhite in color. The whitener mustbe either digestible for the humanbody or harmless in order tomove through the body withoutcomplication.

The third spectrum is a typicalprofile of a water-based spectrum.Strong and broad signals in theregion of -OH structures are visi-

ble (strong 3,300, strong 1,600 andbroad weaker signal around 2,100cm-1). In the fingerprint rangesome additional signals show theingredients mixed with the water-based cream. Not all of the signalsrelate to the typical fat signals,because the 1,740cm-1 signal forfatty acids is missing. In this case,paraffin and Vaseline instead offatty acids form the base of thecream. The different alcohols inthis cream have related signals atabout 1,044 and 1,082 cm-1. Thepharmaceutical ingredient Aciclo-vir with 5 % (weight %) is includ-ed in the cream.

The signal at 1,380 cm-1 can be thevibration of the -(C-N) moleculargroup. Other reference signals ofamine structures overlap with thewater signals and cannot be seendirectly.

The fourth spectrum shows thatnot only water is the base of thepharmaceutical product Bepan-thol. Near to the broad signal ofwater, a sharp signal in the rangeof the fatty acids at 1,740 cm-1

makes a difference. This signal isrecognized in the spectra for thebalsam and the UV protectioncream. It is the one for fatty acids.In addition, Bepanthol includesDexpanthenol and Ceramides.

Conclusion

FTIR is an exceptionally versatiletechnique offering high levels ofsensitivity and specificity whileneeding very little time or effortto perform. The sequence frommeasurement to library matchtakes only a few clicks of themouse, and samples can be meas-ured in a few seconds simply bydispensing solids or liquids ontothe single-crystal ATR. Some samples can be measured withgreater sensitivity using a multi-ple-bounce ATR design.

The infrared comparison showsspectra for four products relatingto the ingredients of the creamsand balsam. The spectra are domi-nated by water and fat or wax-style materials. Where the contentof the pharmaceutical ingredient ismore than 1 %, identification ispossible.

Instruments:FTIR: IRAffinity-1Accessory: DuraSamplIR, diamond basedsingle reflection unitStructure analysis: IRAnalyze version 1.3Libraries: Sadtler, Shimadzu

APPLICATION

Dimitris Georgantas*,Athanasios Lintas**,Konstantinos Kraniotis**,Panagiotis Kotsokolos**,Manos Barmpounis*

*Applications Department ofN.Asteriadis S.A., 31 DervenionStr. & Poseidonos Str. 14451 Metamorfossi Athens, Greeceemail: [email protected]**Motor Oil (Hellas) CorinthRefineries S.A.

C urrent and growing interna-tional governmental re-quirements to add fatty acid

methyl esters (FAMEs) to dieselfuel have had an unintended side-effect of leading to potentialFAMEs contamination of jet tur-

into diesel fuel that impact on jetfuel:

1: FAMEs are active and tend tostick to metal or glass surfaces.This creates new risks of crosscontamination where supply

FAMEs can adsorb onto the sur-face of the pipeline, contaminatingfuel that follows, including avia-tion turbine fuel (AVTUR).

There are two main issues withintroduction of FAMEs content

bine fuel in multi-fuel transportfacilities, with industry-wide con-cern. The contamination of avia-tion fuel with fatty acid methylesters can arise through the use ofmulti-product pipelines or tanksfor fuel supply and distribution.


FAMEs in aviation turbine fuel – a risk? GC/MS analysis of Trace Fatty Acid Methyl Esters

1008060402010

86420

1000800600400200100

80604020

0

0200400600800900920940960980

1000

1010101010101010101010

Table 1: Volumetric dilutions for preparing standards in the range 0 - 100 mg/kg from the 100 mg/kg working standard

Nominal std conc. (mg/Kg) Volume WSS (μL) Volume dodecane (μL) Volume internal standard (μL)


APPLICATION

chains handle both jet fuel andbiodiesel.

2: FAMEs are non-hydrocarbonfuel components. But jet fuelspecification states explicitlythat only hydrocarbon compo-nents or approved additives areallowed.

The international jet fuel specifi-cations (e.g. DEF STAN 91-91)limit FAME content to less than 5 mg/kg (mg/kg w/w). Levelsabove 5 mg/kg render the fuelout-of-specification.

Current methods for determiningFAME content in aviation fuel usea polar type GC column for theseparation with mass spectrome-try (MS) for detection. The testsample of AVTUR is run togetherwith an internal standard on theGC-MS to separate the polarFAME relative to the non-polarhydrocarbon matrix of the jet fueland any mineral diesel contamina-tion. Due to natural backgroundof high-end naphtha componentspresent in some samples, completeseparation is not possible and amultiple selective ion monitoring(SIM) is performed. The ions usedin the SIM method are indicativeof the FAMEs and not the back-ground hydrocarbon matrix of thefuel, therefore distinguishingFAMEs from hydrocarbon avia-tion fuel.

Experimental

The analysis was performed on aShimadzu GCMS-QP2010 SEwith a split/splitless injector. A1.0 μL splitless injection intro-duced the standards and the sam-ples with the aid of an AOC-20i

autosampler and chromatographicseparation was achieved on a 60 m x 0.25 mm Øi x 0.50 μm HP-INNOWAX column.

Detailed instrument parametersare presented below:

Instrumental conditions

GC oven temperature pro-grammeInitial temp 150 °C and hold for 5 min.Ramp at 12 °C per min until 200 °C and hold for 17 min.Ramp at 3 °C per min until 252 °C and hold for 6.5 min.Total run time: 50 min.

Sample injectionSplitless injector, temperature 260 °C.Sample volume 1 μL.

MS ConditionsIon source temperature: 200 °CInterface temperature: 255 °CDetector Voltage: 0.83 kV

SIM measurement:See table 3

Procedure

The experimental procedure wascarried out according to IP 585/10.A stock standard solution of 1,000mg/kg of FAMEs as well as a 1,000mg/kg of internal standard (C17:0d33) were prepared in dodecane.A 100 mg/kg working standard ofFAMEs was then prepared as wellas all standards derived from itaccording to table 1.

Two calibration plots for eachfatty acid methyl ester were used,

covering the working ranges 0mg/ kg to 10 mg/kg (using the 0,2, 4, 6, 8, 10 mg/kg standards) and0 mg/ kg to 100 mg/kg (using the0, 20, 40, 60, 80, 100 mg/kg stan-dards). The lower working rangeshould be applied for all FAMEspresent in any sample at less than10 mg/kg. The 0 mg/kg to 100mg/kg calibration range shall beapplied for all FAME species pres-ent in any sample at greater than10 mg/kg. In figure 1, a chro-matogram of a 10 mg/kg standardof FAMEs is shown.

Correlation coefficients of all fit-ted calibration curves were excel-lent as can be seen in table 2 andfigure 2. The total FAME concen-tration is calculated by summingthe concentrations obtained for

Figure 1: Chromatogram of a 10 mg/kg FAMEs standards

25.0 27.5 30.0 32.5 35.0 37.5 40.0 42.5

0.250.500.751.001.251.501.752.002.252.502.753.003.253.503.754.00

(x 10,000)

Figure 2: Calibration curves of FAMEs at range of 10 - 100 mg/kg

0.0 25.0 50.0 75,0 Conc. Ratio

0.0 25.0 50.0 75.0 Conc. Ratio

0.0 25.0 50.0 75.0 Conc. Ratio

0.0 25.0 50.0 75.0 Conc. Ratio

0.0 25.0 50.0 75.0 Conc. Ratio

0.0 25.0 50.0 75.0 Conc. Ratio

0.0

1.0

2.0

3.0

4.0

5.0

0.0

1.0

2.0

3.0

4.0

5.0

0.0

0.5

1.0

1.5

2.0

0.0

1.0

2.0

3.0

4.0

5.0

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0.0

2.5

5.0

7.5

Area Ratio (x 10) Area Ratio (x 10)



the six specified FAMEs using thespecified calibration ranges.

As a fixed volume of sample isinjected, the density of the sam-ples will vary and differ from thedodecane used to prepare thestandards. A density correctionfactor is therefore applied to theconcentrations calculated from thestandard calibration according towith the equation:

Total FAME, mg/kg = (measuredFAME, mg/kg) x (density ofdodecane)/ (sample density).

Quantitation as well as implemen-tation of density correction factorwas performed automatically bythe GCMS solution program. �

APPLICATION

Although the method requires a0.5 mg/kg detection limit for eachsubstance (signal to noise 10 : 1),the instrument achieved muchhigher sensitivities (signal to noisefrom 50 to 200 : 1 depending onthe substance) with a low detectorvoltage (0,83 kV) as can be seen infigure 3.

Conclusions

The Shimadzu GCMS-QP2010 SEwas proven to be an excellent plat-

From Bio-Diesel Fuel, In AviationTurbine Fuel – GC-MS With SelectiveIon Monitoring/Scan Detection Meth-od, The Energy Institute, London, UK

[2] JIG (Joint Inspection Group),Bulletin No 21, November 2008,www.jigonline.com

[3] Ministry of Defence, DefenceStandard 91-91, Issue 6, April 2008,UK Defence Standardization

od has been successfully imple-mented in Motor Oil (Hellas)Corinth Refineries S.A., one of thelargest petroleum companies inGreece and to our knowledge theonly Greek laboratory performingit.

References[1] IP 585:2010, Determination Of Fatty

Acid Methyl Esters (Fame), Derived

form for the determination ofFAMEs in aviation turbine fuelsaccording to the IP 585 test meth-od. The method showed excellentlinearity at both high and low con-centration levels as well as highsensitivity even with low detectorvoltage. All method parameters,internal standard calibrationcurves and density correction fac-tor were successfully implementedin the GCMS Solution software,allowing automatic quantificationof the samples. Finally, this meth-


PRODUCTS

N ew micro cell holders ex-tend the wide range ofaccessories for the UV-

2600/UV-2700 spectrophotometryseries. This UV-VIS-NIR spec-troscopy instrument series owesits high performance to the patent-ed ‘LO-RAY-LIGH®’ diffractiongratings.

Micro cell holders for integrating spheres

With the introduction of the UV-2600, the ISR-2600Plus integrat-ing sphere has been implemented,

a unique feature for this instru-ment class enabling measurementsin the near-infrared range up to1,400 nm. For both this new inte-grating sphere and Shimadzu’sentire model range, an additionalaccessory is now available for themeasurement of small samples.Until now, small samples had to

New accessoryfor the UV series

Large samplesMedium samplesSmall samples

Ø 10 - Ø 14 · 10 - 14 mmØ 6 - Ø 14 · 6 - 12.5 mm

Ø 3 - Ø 9 · 4 - 8 mm

Table 1: Dimensions of the micro sample holders for Shimadzu's integrating spheres

Sample holder Sample sizeFigure 1: Micro sample holder for samples of

10 -14 mm internal diameter or rectangular

shaped samples; maximum diameter of the

light beam for transmittance measurement

is 5 mm

Figure 3: Chromatogram of a 0.5 mg/kg spiked aviation fuel and overlay chromatograms

of 0,5 - 6 mg/kg of C16 :0

25.0 27.5 30.0 32.5 35.0 37.5 40.0 42.50.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1(x 10,000)

C16:0C17:0C18:0C18:1C18:2C18:3

0.9930.9950.9970.9970.9980.998

0.9970.9960.9960.9970.9970.995

Table 2: Correlation coefficients of the calibration curve

FAME R2 (0 - 10 mg/Kg) R2 (0 - 100 mg/Kg)

C16:0C17:0 (d33) Internal standard

C17:0C18:0C18:1C18:2C18:3

Table 3: SIM measurement

FAMEs to be detected SIM ions to be used for quantification

227, 239, 270, 271317241, 253, 284255, 267, 298264, 265, 296262, 263, 264, 294, 295236, 263, 292, 293

be embedded in barium sulfate(BaSO4) as part of the sample pre-paration process, which is not nec-essary using the new micro sampleholders. They are supplied in apack of three holders for varioussample sizes.

Table 1 lists the dimensions of thevarious samples. The samples canbe round (Ø) or square (�). Smalllenses, filters or glasses can befixed securely – they are lockedinside the holder very easily viasliding elements. The sliding ele-ments also function as masks forthe measurement of smaller sam-ples. The holders are fixed to the

corresponding measurement posi-tions of the integrating sphere,enabling both transmittance andreflectance measurements.


APPLICATION

I n elemental analysis, ICP, AASand EDX methods differ interms of sample preparation

complexity, lowest possible detect-able concentrations, the numberof simultaneously measurable ele-ments and the overall measurabili-ty of an element. While ICP andAAS offer better detection limits,sample preparation can usually beomitted when using EDX. Carbonto uranium or sodium to uraniumcan be measured in solid as well asin liquid samples. Depending onthe element and sample, the detec-tion limit reaches down to the sin-gle digit ‘ppm range.’

After selecting a suitable methodfor an analytical question, it isimportant to be able to determinethe accuracy of the measurementresults. Sometimes the analyticalmethod or the measurementinstrument are blamed for non-optimum measurement results ortoo high overall standard devia-tions.

The total measurement error, how-ever, is the sum of many individ-ual errors. The first error often

A standard deviation of the meas-urement results of 0.2 % wasachieved. This reflects the meas-urement accuracy of the instru-ment in the present case.

Looking at the total error of anEDX measurement, 5-fold up to

arises during sampling. In thisstep, it is important to obtain asample which is as representativeas possible. Furthermore, the sam-ple should be homogenous, and allelements present in the samplemust be available for the appliedmeasurement method. It can,however, still be possible that thesample itself changes the measure-ment result, either as a result ofinteraction between the samplecomponents or due to interactionwith the measurement method.Weighing errors or errors due toincorrect calibration distort thefinal result in addition.

The instrument error is often thesmallest factor contributing to thetotal error of a measurement re-sult.

In the present case, a potassi-um/manganese mixture was fine-ly ground, pressed into a tabletand measured 20 times usingShimadzu’s EDX-800P. The sam-ple was not repositioned in thesample chamber, thereby exclu-ding errors arising from possiblesample inhomogeneity.

Technical failure or ‘human factor’?Measurement inaccuracies in X-ray fluorescence spectroscopy

123456789

1011121314151617181920

AverageStandard deviation

37.236.937.136.936.937.036.937.036.837.136.737.036.836.836.836.737.236.636.836.8 36.9

0.2

62.863.162.963.163.163.063.163.063.262.963.363.063.263.263.263.362.863.463.263.263.1

0.2

Measurement K (ppm) Mn (ppm)

Figure 1: Energy dispersive X-ray fluorescence spectrometer EDX-800P

Table 1: Measurement results: K/Mn mixtures

10-fold higher standard deviationsare quite realistic. It is a recurringchallenge for the experimenter toreduce these errors as much aspossible using suitable samplingand sample preparation methods.This is a challenge in whichShimadzu is happy to assist.

Figure 2: First issue with new design

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ly active companies, small busi-nesses or large enterprises alike.

In order to reach prospects andmarkets in times of global busi-ness relationships with a consis-

Global structure – Global Designtent brand recognition, Shimadzuhas developed a new Global De-sign for all its communicationchannels – advertisements, bro-chures, mailings etc. Shimadzu’swebsite and the ‘Shimadzu News’apply this new design as well.

Shimadzu Europe website

The new web presence has beenimplemented for the Europeanbusiness units ‘Analytics’ and‘Medical Technology’ – white,subtle, clear structuring and largeimages characterize Shimadzu’s

new look. This way, the corpo-rate as well as the product brandscan be experienced consistently.The websites of the individualEuropean subsidiaries will be re-leased shortly.

Shimadzu News

»The times they are a-Changin«– so do the ‘Shimadzu News.’Since its first issue, this well-established print medium hasperiodically adapted and updatedits content and look over theyears. The new Global Designhas been applied for the recentfacelift.

In fact, the first issue featuringthe new look was already pub-lished at the end of 2012. One ofthe most obvious changes is the

Figure 1: New website following Global Design guidelines

Figure 3: Clear and well structured – the new interior design of the Shimadzu News

design of the front-page with alarge key-visual related to cur-rent topics of analytics. Thedesign of the inner pages is mini-malist and has been optimizedregarding reader-friendliness andreadability.

In three issues per year, theShimadzu News articles covernew applications, products anddevelopments in analyticalinstrumentation and materialstesting. The Shimadzu News isalso available as iOS App andWeb App.

Shimadzu News

iOS-App

Shimadzu News

WebApp

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