| Abstract: | A gas-liquid chromatographic-mass spectrometric method of determining the position of oxygen atoms on polyfunctional fatty acids has been explored. The method consists of reduction of keto, hydroperoxy, epoxy, and carboxylic acid groups with LiAlH(4) to the corresponding alcohols; trimethylsilylation with bis(trimethylsilyl)acetamide; and analysis by means of the combined gas-liquid chromatograph-mass spectrometer. The following compounds were analyzed: 9-mono-, 9,10-di-, 9,10,12-tri-, and 9,10,12,13-tetrahydroxystearic acids and the corresponding derivatives of octadecan-1-ol. The reduction products of 9,10-epoxystearic acid and a mixture of linoleic acid 9- and 13-hydroperoxides were also analyzed. The position of the oxygen function in the original molecule can be deduced rapidly and accurately. |
