Analysis of fatty acid methyl esters with high accuracy and reliability : III. Literature review of and investigations into the development of rapid procedures for the methoxide-catalysed methanolysis of fats and oils

Abstract

The literature leading to the development of rapid procedures for the preparation of fatty acid methyl esters for gas—liquid chromatography by methoxide-catalysed methanolysis of fats and oils is reviewed. A rapid and reliable procedure utilizing the best features of the literature methods was developed and shown to give excellent quantitative results in the difficult case of a triacylglycerol primary standard mixture simulating coconut oil. Evidence is presented that brief refluxing of the reaction mixture is advantageous and that removal of methoxide by aqueous extraction at the completion of the reaction, as distinct form injecting the whole reaction mixture, is essential if good quantitative resutls are to be obtained. The method is faster and simpler than the existing international procedures, and the ester solution may be ready for injection into the chromatograph in about 2 min.