Analysis of common fatty acid glycerides by gas chromatography

A method is described for the determination of 25 common fatty acid mono-, di-, and triglycerides and their components and mixtures by packed-column gas chromatography after isolation and derivatization. The method is applied to two commercial materials, a polypropylene resin and a hand lotion. The glycerides along with glycerol and free fatty acids are first separated from the host by refluxing with 2-propanol containing an internal standard. The extract is derivatized and the compounds are identified and measured by gas chromatography. The chromatograms show sharp peaks, unique retention times and reproducibility in the range of 2–5%. Several positional isomers of the fatty acid glycerides were tested but found not to be resolved under the conditions used. Optical isomers and cis-trans isomers of unsaturated acids were not tested.