Abstract: 2-Amino-2-methylpropanol was developed as chemical modifying reagent of fatty acids so as to modify carboxyl group into nitrogen-containing heterocycle which effectively suppressed the migration of double bonds of the alkenyl under the electron impact source.The empirical rule in which the position of double bonds of olefinic acids was located was refered to electron impact analyzing spectra of the chemical products modified by 2-amino-2-methylpropanol of the fatty acids in spirulina. 11 fatty acids were identified according to the analysis of GC-EIMS and the position of double bonds of the fatty acids from spirulina was located. Spirulina consists of the fatty acids of C 14～C22.The contents of the unsaturated fatty acids and the polyunsaturated fatty acids are 68.34% and 54.48% respectirely, and the main component of the polyunsaturated fatty acids is 9,12,15-linolenic acid whose relative content is 36.22%.Besides, 9-tetradecenoic acid,6-octadecenoic acid, 11-eicosenoic acid and 4,7,10,13,16,19- docosahexenoic acid are first identified. Therefore, this method provides a new technical tool for the location of double bonds in the unsaturated fatty acids.

Key words: 2-Amino-2-methylpropanol, chemical modification, spirulina, fatty acids, gas chromatography-elec- tron impact mass spectrometry