葵子油脂肪酸2-氨基-2-甲基-丙醇化学修饰气相色谱-质谱分析

Analysis of Fatty Acid in Sunflower Oil by Gas Chromatography-Mass Spectro-metry with Chemical Modifying Reagent 2-Amino-2-methylpropanol

以2-氨基-2-甲基-丙醇为脂肪酸的化学修饰试剂,气相色谱-电子轰击质谱(GC-EI MS)分析葵子油脂肪酸。2-氨基-2-甲基-丙醇将脂肪酸羧基修改为含氮杂环,使在EI源中避免了链烯基中碳碳双键的移动。解析了葵子油脂肪酸2-氨基-2-甲基-丙醇化学修饰产物的EI质谱图,讨论了烯酸中碳碳双键的定位规则,确定了葵子油脂肪酸中碳碳双键的位置。鉴定出葵子油6种脂肪酸,不饱和脂肪酸相对含量为89.41%,其中人体必需脂肪酸9,12-十八碳二烯酸含量占65.30%。本方法为不饱和脂肪酸中双键的定位提供了新的技术手段。

A gas chromatography - electron impact mass spectrometry method was developed for analyzing the compositions of the fatty acids in sunflower oil. 2-Amino-2-methylpropanol was used as the chemical modifying reagent of fatty acids to modify the carboxyl group into nitrogen-containing heterocycle which would effectively prevent the migration of carbon double bonds of the alkenyl in the electron impact source. The electron impact mass spectra of the chemical products modified by 2-amino-2-methylpropanol of the fatty acids in sunflower oil were analyzed; the allocation rule for the carbon double bonds in olefinic acids was discussed and the location of the carbon double bonds of the fatty acids in sunflower oil was confirmed. Six fatty acids were identified. The contents of the unsaturated fatty acids and 9, 12-1inoleic acid were 89.41% and 65.30%, respectively, This method can be used to determine the location of carbon double bonds in the unsaturated fatty acid.