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



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


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.


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How to Cite

Ravi Kiran C, Reshma MV, Sundaresan A. Separation of cis/trans fatty acid isomers on gas chromatography compared to the Ag-TLC method. Grasas aceites [Internet]. 2013Mar.30 [cited 2024Jul.25];64(1):95-102. Available from: