The Content of Fat and Polyenoic Acids in the Major Food Sources of the Arctic Diet. Localization of Double Bonds in Fatty Acids by Means of Mass Spectrometry of Fatty Acid Pyrrolidides

Location of double bonds in fatty acids of fish oil and rat testis lipids. Gas chromatography-mass spectrometry of the oxazoline derivatives

A new approach to the derivatization and analysis of long chain polyunsaturated fatty acids is described. The method is based on the formation of 2-alkenyl-4,4-dimethyloxazolines by condensation of the starting material with 2-amino-2-methylpropanol. The derivatization method is rapid, efficient and specific with respect to the chain feature of the parent acids. Volatility, comparable with that of the corresponding simple esters, and improved gas chromatographic separation are achieved without difficulty. The derivatives exhibit clear and regular fragmentation patterns that allow easy discrimination of positional isomers and assignment of double bond location in the chain.

A comparison of pyrrolidide and picolinyl ester derivatives for the identification of fatty acids in natural samples by gas chromatography-mass spectrometry

The pyrrolidide and picolinyl ester derivatives of the fatty acids in two natural lipid samples rich in unsaturated fatty acids, pig testis lipids and cod liver oil were satisfactorily resolved on capillary columns of fused silica coated with stationary phases of varying polarity. The picolinyl esters, in particular, when subjected to gas chromatography-mass spectrometry on a column containing a cross-linked methyl silicone, gave distinctive mass spectra, which could be interpreted in terms of both the numbers and positions of the double bonds.