Chromatographic determination of cis-trans monoethylenic unsaturation in fats and oils--A review.

Chromatographic procedures for the determination of geometric and positional monoethylenic fatty-acid isomers in fats and oils have been reviewed. For the determination of these isomers, the procedure involving prep GLC isolation of the monoethylenic ester fractions on polar stationary phases, further separation and determination of geometric isomers by prep Ag+/TLC, and determination of positional isomers by reductive ozonolysis, is considered to be the most suitable for the analysis of a wide range of oils. Although, in this review, emphasis has been placed on monoethylenic isomers, most of the techniques described are also applicable in the study of polyenoic isomers.