Some Contemporary Applications of Open‐Tubular Gas‐Liquid Chromatography in Analyses of Methyl Esters of Longer‐Chain Fatty Acids

The application of wall‐coated open‐tubular (capillary) gasliquid chromatographic columns to some current analytical problems in fat research is described. The liquid phase SILAR‐5CP in commercially available stainless steel columns has been found to be particularly suitable for rapid screening of fats and oils for total docosenoic acid without interference from other components. Differentiation of two important 22:1 isomers (erucic acid from vegetable oils and cetoleic acid from marine oils) is possible and the erucic acid content of an oil or fat can be estimated in approximately 20 minutes. The effects of partial hydrogenation of fats on the gas‐liquid chromatography of these fatty acid structural details are reviewed. The use of other liquid phases such as butanediolsuccinate polyester, and the advantages of SILAR‐7CP for study of geometrical isomers in wall‐coated open‐tubular columns are discussed briefly, and also the potential of support‐coated open‐tubular columns for similar analyses of longer‐chain fatty acids.