Gas chromatography ofCis‐Trans fatty acid isomers on nitrile silicone capillary columns

Three nitrile silicone polymers have been evaluated as liquid phases for gas chromatographic separation of the geometric isomers of methyl oleate, methyl linoleate, and methyl linolenate on capillary columns. A polymer of ॆ‐cyanoethylmethylsiloxane proved the most effective. This liquid phase separated oleate from elaidate, resolved the four geometric isomers of linoleate into three peaks, and divided the eight geometric isomers of linolenate into six peaks. Two other copolymers of dimethylsiloxane and ॆ‐cyanoethylmethylsiloxane gave poorer resolution ofcis‐trans isomers, but showed different elution patterns for the geometric isomers of linoleate and linolenate.