Separation and determination of oleic and cis-vaccenic acids by gas-liquid chromatography mass spectrometry using a polar cyanopropylsiloxane liquid phase.

The separation and quantification of the monoenoic isomeric oleic (cis-9-octadecenoic) and cis-vaccenic (cis-11-octadecenoic) acids as their pyrrolidine derivatives, was studied with a gas chromatograph mass spectrometer system using mass chromatography. By monitoring the characteristic ions of the pyrrolidine derivatives of oleic (m/z 208 and 222) and cis-vaccenic (m/z 210 and 224) acids, both derivatives were separated. The ratio of m/z 210 to 208 was proportional to the relative amounts of cis-vaccenic to oleic acid. By this method, the content of cis-vaccenic acid in choline phosphoglycerides from rat liver and Yoshida ascites hepatoma (AH 7974) was determined.