Analysis of the monoenoic fatty acid distribution in hydrogenated vegetable oils by silver‐ion high‐performance liquid chromatography

A silver‐ion high‐performance liquid chromatography column (hexane/acetonitrile as solvent, ultraviolet detection) was used to analyze the fatty acid distribution (as fatty acid methyl esters) of a representative sample of hydrogenated oil. Fractions containingcis‐ andtrans‐18:1 isomers were readily separated. The positional fatty acid isomers were separated by rechromatographing these fractions. The elution order and percent compositions were compared with results obtained by gas chromatography. Of the Δ8 to Δ14trans‐18:1 isomers, only the Δ8 and Δ9 pair could not be separated. The Δ8 and Δ9cis‐18:1 pair also could not be separated, and the Δ10 isomer was poorly separated from this pair. Area percents were comparable to results obtained by gas chromatography.