Abstract
A new analytical method by gas chromatography-mass spectrometry is described for detection and determination of [2, 2-2H2] stearic and [2, 2-2H2] oleic acids as stable isotopic tracers. The content of methyl esters of the [2, 2-2H2] fatty acids in a mixture of the corresponding labeled and unlabeled fatty acid methyl esters can be calculated from the proportion of the peak intensities of ions at m/z 76 and 74 due to the McLafferty rearrangement of fatty acid methyl esters. The method was applied to trace the nonenzymic and enzymic interesterification reactions using [2, 2-2H2] fatty acids as tracers.
