Grasas y Aceites, Vol 64, No 1 (2013)

Separation of cis/trans fatty acid isomers on gas chromatography compared to the Ag-TLC method

C. Ravi Kiran
National Institute for Interdisciplinary Science and Technology (formerly RRL), Council of Scientific and Industrial Research, India

M. V. Reshma
National Institute for Interdisciplinary Science and Technology (formerly RRL), Council of Scientific and Industrial Research, India

A. Sundaresan
National Institute for Interdisciplinary Science and Technology (formerly RRL), Council of Scientific and Industrial Research, India


The present study investigates the separation of the cis/trans isomers of fatty acids on the 75 m SP2560 column under different gas chromatographic (GC) conditions including an isothermal program and a time-temperature program. The time-temperature program showed improved separation of cis/trans isomers of C14:1, C16:1, C18:1, C18:2 and C18:3 fatty acids along with short chain fatty acids compared to the isothermal program. The separation of trans/trans isomers of C18:1 fatty acids including elaidic acid (C18:1 ∆9t) and vaccenic acid (C18:1 ∆11t) was difficult with the time-temperature program. The thin layer chromatography impregnated with silver nitrate (Ag- TLC) method was performed to separate cis/trans fractions and GC analysis was carried out with the trans fraction. But GC analysis showed a co-elution of trans isomers of C18:1 fatty acid. Thus the study shows that a time-temperature programmed GC method with the highly polar cyanopropyl column is sufficient to resolve trans fatty acids along with short chain fatty acids when a large number of samples has to be analyzed.


Ag-TLC fractionation; Gas chromatography; Resolution; Trans fatty acids

Full Text:



AOCS. 2003. Official methods and recommended practices of the American Oil Chemist's Society. In Firestone (Ed.), 5th edition, Champaign. IL.

Aro A, Kosmeijer-Schuil T, Bovenkamp P, Hulshof P, Zock P, Katan M. 1998. Analysis of C18:1 cis and trans fatty acid isomers by the combination of gasliquid chromatography of 4,4-dimethyloxazoline derivatives and methyl esters. J. Am. Oil Chem. Soc. 75, 977-985.

Berezkin VG, Zagainov VF, Ivanov PB. 2003. Carrier gas as a new factor influencing the selectivity of the gas– stationary liquid phase chromatographic system. J. Chromatogr. A 985, 57-62.

Christe WW. 1989. Gas chromatography and lipids: a practical guide. Oily press limited. First edition.

Delmonte P, Rader J. 2007. Evaluation of gas chromatographic methods for the determination of trans fat. Anal. Biochem. 389, 77-85.

Delmonte P, Fardin Kia A-R, Kramer JKG, Mossoba MM, Sidisky L, Rader JI. 2011. Separation characteristics of fatty acid methyl esters using SLB-IL111, a new ionic liquid coated capillary gas chromatographic column. J. Chromatogr. A 1218, 545-554. PMid:21176911

Elke Hahn-Deinstrop. 2006. Applied Thin Layer Chromatography. Best practice and Avoidance of Mistakes. WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Second Edition.

Ettre LS. 1993. Nomenclature for chromatography. Pure Appl. Chem. 65, 819.

Folch J, Lees M, Stanley GHS. 1957. A simple method for the isolation and purification of total lipids from animal tissues. J. Biol. Chem. 226, 497-509. PMid:13428781

Fournier V, Destaillats F, Hug B, Golay P-A, Joffre F, Juanéda P, Sémon E, Dionisi F, Lambelet P, Sébédio J-L, Berdeaux O. 2007. Quantification of eicosapentaenoic and docosahexaenoic acid geometrical isomers formed during fish oil deodorization by gas-liquid chromatography. J. Chromatogr. A 1154, 353-359. PMid:17449039

Huang Z, Wang B, Crenshaw AA. 2006. A simple method for the analysis of trans fatty acid with GC–MS and AT™- Silar-90 capillary column. Food Chem. 98, 593-598.

IUPAC. 1987. Standard methods for the analysis of oils and fats and derivatives. 7th Ed., London: Blackwell Scientific Publications.

Juanéda P, Ledoux M, Sébédio JL. 2007. Analytical methods for determination of trans fatty acid content in food. Eur. J. Lipid Sci. Technol. 109, 901-917.

Kramer J, Hernandez M, Cruz-Hernandez C, Kraft J, Dugan M. 2008. Combining Results of Two GC Separations Partly Achieves Determination of All cis and trans 16:1, 18:1, 18:2 and 18:3 Except CLA Isomers of Milk Fat as Demonstrated Using Ag-Ion SPE Fractionation, Lipids 43, 259-273. PMid:18214567

Ledoux M, Laloux L, Wolff RL. 2000. Analytical methods for determination of trans-C18 fatty acid isomers in milk fat. A review. Analysis 28, 402.

Micha R, Mozaffarian 2008. Trans fatty acids: effects on cardiometabolic health and implications for policy. Prostag. Leukotr. Ess. 79, 147-152.

Morris LJ. 1966. Separations of lipids by silver ion chromatography. J. Lipid. Res. 7 (6):717-732 PMid:5339485

Mjøs SA. 2005. Properties of trans isomers of eicosapentaenoic acid and docosahexaenoic acid methyl esters on cyanopropyl stationary phases. J. Chromatogr. A 1100, 185-192. PMid:16236287

Mjøs SA, Haugsgjerd BO. 2011. Trans Fatty Acid Analyses in Samples of Marine Origin: The Risk of False Positives. J. Agric. Food Chem. 59, 3520-3531. PMid:21370819

Molkentin J, Precht D. 1995. Optimized analysis transoctadecenoic acids in edible fats. Chromatographia 41, 267-272.

Momchilova S, Nikolova-Damyanova B, Christie WW. 1998. Silver ion high-performance liquid chromatography of isomeric cis- and trans-octadecenoic acids: Effect of the ester moiety and mobile phase composition. J. Chromatogr. A 793, 275-282.

Mozaffarian D, Katan MB, Ascherio A, Stampfer MJ, Willett WC. 2006. Trans Fatty Acids and Cardiovascular Disease. New Engl. J. Med. 354, 1601-1613. PMid:16611951

Phillips K, Ruggio D, Amanna K. 2010. Optimization of Standard Gas Chromatographic Methodology for the Determination of Trans Fat in Unlabeled Bakery Products. J. Food Anal. Methods 3, 277-294

Ragonese C, Tranchida PQ, Dugo P, Dugo G, Sidisky LM, Robillard MV, Mondello L. 2009. Evaluation of Use of a Dicationic Liquid Stationary Phase in the Fast and Conventional Gas Chromatographic Analysis of Health-Hazardous C18 Cis/Trans Fatty Acids. Anal. Chem. 81, 5561-5568. PMid:19480396

Ratnayake WMN, Beare-Rogers JL. 1990. Problems of Analyzing C18 Cis- and Trans-Fatty Acids of Margarine on the SP-2340 Capillary Column. J. Chromatogr. Sci. 28, 633-639.

Ratnayake WMN, Plouffe JL, Pasquier E, Gagnon C. 2002. Temperature-sensitive resolution of cis- and trans-fatty acid isomers of partially hydrogenated vegetable oils on SP-2560 and CP-Sil 88 capillary columns. J. Am. Oil Chem. Soc. 85, 1112-1118.

Ratnayake WMN, Hansen LS, Kennedy PM. 2006. Evaluation of the CP-Sil 88 and SP-2560 GC Columns Used in the Recently Approved AOCS Official Method Ce 1h-05: Determination of cis-, trans-, Saturated, Monounsaturated and Polyunsaturated Fatty Acids in Vegetable or Non-ruminant Animal Oils and Fats by Capillary GLC Method. J. Am. Oil Chem. Soc. 83, 475-488.

Ruiz-Jiménez J, Priego-Capote F, de Castro MD. 2004. Identification and quantification of trans fatty acids in bakery products by gas chromatography–mass spectrometry after dynamic ultrasound-assisted extraction. J. Chromatogr. A 1045, 203-210. PMid:15378896

Tasan M, Gecgel U, Demirci M. 2011. Comparison of geometrical isomerization of unsaturated fatty acids in selected commercially refined oils. Grasas Aceites 62, 284-289.

Tsuzuki W, Matsuoka A, Ushida K. 2010. Formation of trans fatty acids in edible oils during the frying and heating process. Food Chem. 123, 976-982.

U.S. Food and Drug Administration 2003. Food labeling: trans fatty acids in nutrition labeling, nutrient content claims, and health claims. 68 Federal Register 41433-41506 (codified at21 CFR Åò101).

Valenzuela A, King J, Nieto S. 1995. Trans fatty acid isomers from hydrogenated fats: The controversy about health implications. Grasas Aceites 46, 357- 365.

Valenzuela A, Delplanque B, Tavella M. 2011. Stearic acid: a possible substitute for trans fatty acids from industrial origin. Grasas Aceites 62, 131-138.

Copyright (c) 2013 Consejo Superior de Investigaciones Científicas (CSIC)

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Contact us

Technical support