evaluation of a new ionic liquid stationary phase with peg

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Evaluation of a New Ionic Liquid Stationary Phase with PEG Like Selectivity L.M.Sidisky, G. A. Baney, J.L. Desorcie, D.L. Shollenberger, G. Serrano, and K.K. StenersonSupelco, Div. of Sigma-AldrichBellefonte, PA 16823 USA

T413102


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Overview of Presentation

• Overview of Ionic Liquids

• Selectivity Evaluations

• Selectivity Ranking/ Assignment

• SLB-IL60

• Applications

• Conclusions

sigma-aldrich.com/il-gc


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• Ionic liquids are a class of solvents with low melting points that consist of organic cations associated with (inorganic or organic) anions

• Ethyl ammonium nitrate (EtNH+3)(NO-

3), which has a melting point of 12 °C, was described in 1914

• P. Walden, Bull. Acad. Imper. Sci. (St. Petersburg) 1800 (1914)

• Today, they are used as solvents, electrically conducting fluids, and sealants

Ionic Liquids: Definition and Uses


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Ionic Liquids: Example Structure

• Benefits• Greater stability compared to polysiloxane polymers and polyethylene glycols

– Lower column bleed, longer life, and higher thermal limits– More resistant to damage from moisture/oxygen

• Numerous combinations of cations and anions are possible allowing for “tailored”selectivity, application, or function

– Dicationic (shown) or polycationic

– Cations, linkages, and/or anions can be changed

– Pendant groups can be added to cations and/or linkages

SLB-IL100

1,9-di(3-vinylimidazolium) nonane bis(trifluoromethyl) sulfonyl imidate


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Common Anions for Ionic Liquid Phases

SN

S CF3

CF3

OO

OO

-

(NTF2-)

S CF3

O

O

O-

(OTf-)


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SLB-IL60Phase Structure

1,12-Di(tripropylphosphonium)dodecane bis(trifluoromethylsulfonyl)imide


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Selectivity Evaluations



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TCEP Column, 110 ºC

0 10 20Time (min)

C13

toluene

3

4 5

6

7

8

1. n-Tridecane2. Toluene3. Ethylbenzene 4. p-Xylene 5. Isopropylbenzene (Cumene) 6. 1,2,4-Trimethylbenzene7. 1,2,4,5-Tetramethylbenzene (Durene)8. Cyclohexanone

Ionic Liquid Test Mix


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SLB-IL59

1. n-Tridecane2. Toluene3. Ethylbenzene4. p-Xylene5. Isopropylbenzene (Cumene)6. 1,2,4-Trimethylbenzene

2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4Time (min)

C13

4 5toluene

3

6

Ionic Liquid Columns, 110 ºC Isothermal

3.0 4.0Time (min)

3,45

6

C13

SLB-IL60

toluene


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1. n-Tridecane2. Toluene3. Ethylbenzene4. p-Xylene5. Isopropylbenzene (Cumene)6. 1,2,4-Trimethylbenzene

2.0 3.0Time (min)

6C13

toluene

4,5

SLB-IL111

Ionic Liquid Columns, 110 ºC Isothermal

SLB-IL100

1.8 2.0 2.2 2.4 2.6 2.8Time (min)

C13

toluene

3

64 5

3


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GC Column Polarity Scale and Naming System



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McReynold’s Number Probes

• Benzene (X)- Aromatics, olefins• Butanol (Y)- Alcohols, nitriles, acids• 2-Pentanone (Z)- Ketones, ethers, aldehydes, esters, epoxides,

dimethyl amino derivatives• Nitropropane (U)- Nitro and nitrile compounds• Pyridine (S)- Bases, N-heterocycles• 2-Methyl-2-pentanol (H)- Branched chain compounds, alcohols• 1-Iodobutane (I)- Halogen compounds• 2-Octyne (K)- Acetylenic compounds• 1,4- Dioxane (L)- Ethers, polyols• cis-Hydrindane (M)- Polycyclic compounds, steroids


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Description of Our Procedure

• Each column is characterized with a series of five probes plus several n-alkane markersto determine the retention index for each probe

• Benzene• Butanol• 2-Pentanone• Nitropropane• Pyridine

• McReynolds Constants are then calculated using the retention index data of the column relative to the retention index data for the same five probes on squalane, the most non-polar GC stationary phase

• The five McReynolds Constants are summed to obtain Polarity (P) values, which are then normalized to SLB-IL100 (set at P=100) to obtain Polarity Number (P.N.) values

Our procedure was proposed by Prof. Luigi Mondello (University of Messina, Italy).


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Visual Representation


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P (Polarity) = sum of the first 5 McReynolds Constants.P.N. (Polarity Number) = Polarity (P) normalized to SLB-IL100 (set at P=100).

Experimentally Determined Polarity Numbers


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SLB-IL60



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Why SLB-IL60?

• Improved inertness over SLB-IL59

• Complimentary selectivity to PEG phases

• Higher maximum temperature than PEG phases

• Lower bleed than PEG phases


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C1-C12 n-Alcohols - 110 °C isothermal

0 10 20 30Time (min)

C12-OLC11-OLC10-OL

C9-OL

C8-OLSLB-IL60

0 10 20 30Time (min)

C8-OL

SLB-IL59

C9-C12 alcohols adsorbed

Severe tailing

Improved Inertness


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Complimentary Selectivity to Wax

2 4 6 8 10 12 14 16Time (min)

SLB-IL60

2 4 6 8 10 12 14 16 18Time (min)

Wax

1. 2-Octanone2. n-C153. n-Octanol4. n-C165. n-C176. n-C187. 2,6-Dimethylphenol8. 2,6-Dimethylaniline9. n-C20

1

2

3

4

5

6

7 8 9

1

2

3

4

5

6

8 79


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0 10 20Time (min)

20000

40000

60000

80000

100000

counts

Higher Max Temp and Lower Bleed than Wax

0 10 20 30Time (min)

20000

40000

60000

80000

100000

AU

SLB-IL60, Tf= 300 °C

29.3pA

Wax #1, Tf= 280 °C

8.3pA

0 10 20 30Time (min)

0

20000

40000

60000

80000

100000

AU

Wax #2, Tf= 300 °C129pA

FID bleed at published

temp. program max


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Applications


• BTEX and n-alkanes• Solvents on the SLB-IL60• Fatty Acid Methyl Esters


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60 °C Isothermal

BTEX + C9 to C14 n-alkanes

0 10 20 30Time (min)

C14C13

C12

C11

C10

C9

B

T

EB

p-Xyl

m-Xyl

o-XylSLB-IL59/SLB-IL60

0 2 4 6 8 10Time (min)

C14C13

C12

C11

C10

C9

o-Xyl

B

T

EBm-Xyl

p-Xyl

SLB-IL76Significantly less retention of aliphatics

IL columns by increasing polarity numbers


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1.0 2.0 3.0 4.0 5.0Time (min)

C14

C13

C12

C11

o-Xylm-Xylp-XylEB

T

B

BTEX + C9 to C14 n-alkanes60 °C Isothermal

SLB-IL111

Most polar IL column

C13 elutes before toluene


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Chlorinated solvents on the SLB-IL60 & Wax

2 4 6 8 10 12Time (min)

1 2

3

4

5

6

7

8 9

10 1112

1. 1,1-Dichloroethylene2. trans-1,2-Dichloroethylene3. Methylene chloride4. 1,1-Dichloroethane5. Carbon tetrachloride6. 1,1,1-Trichloroethane7. Chloroform8. Trichloroethylene9. 1,2-Dichloroethane10.Tetrachloroethene11.1,1,1,2-Tetrachloroethane12.1,1,2,2-Tetrachloroethane

SLB-IL60: 30 m x 0.25 mm I.D. x 0.20 µm Wax: 30 m x 0.25 mm I.D. x 0.25 µm Oven: 40 °C (4 min.), 8 °C/min. to 200 °CHelium, 30 cm/sec, set at 120 °C

SLB-IL60

0 2 4 6 8 10 12 14 16Time (min)

10

25,6

4

3

8

1

7

9 11

12

Wax

All resolved –

yet faster elution


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Ester & Ether solvents on the SLB-IL60 & Wax

1. Methyl formate2. Ethyl formate3. Methyl acetate4. Tetrahydrofuran5. Ethyl acetate6. Isopropyl acetate7. n-Propyl acetate8. 1,4-Dioxane9. Isobutyl acetate10.n-Butyl acetate11. Isoamyl acetate12.n-Amyl acetate13.2-ButoxyethanoC: contaminant (2-Methylbutyl acetate)

SLB-IL60: 30 m x 0.25 mm I.D. x 0.20 µm Wax: 30 m x 0.25 mm I.D. x 0.25 µm Oven: 40 °C (4 min.), 8 °C/min. to 200 °CHelium, 30 cm/sec, set at 120 °C

0 2 4 6 8 10 12 14 16Time (min)

1

2,3

4

56 7 9

8

1011

12

13

Wax

0 2 4 6 8 10 12 14Time (min)

12 3

4

56 7

8

910 11

c

12

13

SLB-IL60


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Cis / trans FAMES on SLB-IL60 vs. PEG Type Phase

11.0 12.0 13.0 14.0 15.0Time (min)

trans cis

C18:1n9 cis / trans FAMEs @ 180 °C

SLB-IL60

21.0 22.0 23.0 24.0Time (min)

PEG

C18:2n6 cis & trans FAME Isomers- 180 °C

10 12 14 16 18 20Time (min)

C18:2n6 tt

C18:2n6 cc

26 28 30 32 34Time (min)

C18:2n6 tt

C18:2n6 cc


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Peak list and run conditions for FAMEs

GC analysis conditions are from methods AOAC 991.39 and AOCS CE-1i-07


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Fame Elution order-SLB-IL 60 compared to Wax

SUPELCOWAX 10

SLB-IL60

17: C18:1n9c18: C18:1n9t19: C18:2n6c20: C18:2n6t

26: C20:3n628: C20:3n335: C22:5n336: C24:037: C22:6n3

Notable elution changes from wax column:1. C18:1n9t elutes before C18:1n9c2. C18:2n6t elutes before C18:2n6c3. C20:3n3 elutes before C20:3n64. C22:6n3 elutes before C22:5n3 and C24:0

C24:0


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PUFA 3 Standard

10 20 30Time (min)

C14:0 C16:0 C16:1n7

C16:2n4C16:3n4

C18:0

C18:1n9

C18:1n7

C18:2n6

C18:3n4

C18:3n3

C18:4n3

C20:1n9C20:3n3

C20:4n6

C20:5n3 , C20:4n3? C22:6n3

C22:5n3

SLB-IL60

10 20 30 40 50Time (min)

C18:2n6

C14:0

C16:0

C16:1n7

C16:2n4C16:3n4

C18:0

C18:1n9

C18:1n7

C18:3n4

C18:3n3

C18:4n3

C20:1n9 C20:3n3

C20:4n6

C20:4n3

C20:5n3

C22:5n3

C22:6n3

Omegawax 250

Same analysis conditions as 37-component mix


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Extract of Farm-Raised Atlantic Salmon

10 20 30 40 50Time (min)

C14:0

BHT C16:0

C16:1n7

C16:2n4C16:3n4

C18:0

C18:1n9

C18:1n7

C18:2n6

C18:3n6

C18:3n4

C18:3n3C18:4n3

C20:1n9 C20:3n3C20:4n6

C20:4n3

C20:5n3

C22:5n3

C22:6n3

Omegawax 250

10 20 30Time (min)

C18:3n4

C20:4n6

C14:0

C16:0

C16:1n7

C16:2n4 C16:3n4 C18:0

C18:1n9

C18:1n7

C18:2n6

C18:3n6

C18:3n3C18:4n3

C20:1n9C20:3n3

C20:5n3C20:4n3?

C22:1n9

C22:6n3C22:5n3

SLB-IL60

Samples prepared using AOCS Official Method Ce 1k-09; BHT added as an antioxidant


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Conclusions• Ionic Liquids are different than traditional polymer GC phases

• Not susceptible to same stability issues as siloxane and PEG based phases

• More “parts” to change thus more possible chemistries possible selectivity

• Higher temp. limit than traditional phase of comparable polarity

• Ionic Liquids extend the polarity range of GC phases• SLB-IL111 more polar than any traditional phase

• SLB-IL60 Ionic Liquid Phase offers• Improved inertness over SLB-IL59

•Complimentary selectivity to PEG phases

•Higher maximum temperature than PEG phase

•Lower bleed than PEG phases

•Can be used for a wide variety of applications


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Acknowledgements• Prof. Daniel Armstrong, U. Texas Arlington• Prof. Luigi Mondello, U. Messina, Messina, Italy• Supelco R&D Team• Our customers worldwide


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Thank You

evaluation of a new ionic liquid stationary phase with peg

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