油脂中脂肪酸的分析测定

Determination of fatty acids in oils

采用毛细管气相色谱法测定了几种油脂的脂肪酸含量。对测定条件进行了选择,色谱柱为SE-30弹性石英毛细管柱(25 m×0.22 mm×0.2μm),柱温为190℃,载气流速为1 mL/min,分流比为1∶100。对棉籽油、花生油、大豆油、小米乳芽油、猪油中所含脂肪酸进行了分析,结果表明,所测油脂中不饱和脂肪酸的含量普遍高于饱和脂肪酸,其中大豆油中亚油酸的质量分数(下同)最高,达60.02%;植物油中不饱和脂肪酸的含量高于猪油,其中小米乳芽油的最高,达84.33%,而猪油只有50.43%。

A method is developed for the determination of fatty acids in oils by capillary gas chromatography. The analysis conditions are optimized. A SE-30 capillary column（25 m×0.22 mm×0. 2 μm） is used with the column temperature at 190 ℃, the flow rate of carrier gas at 1 mL/min, and the split ratio of 1 ： 100. The contents of fatty acids in cotton seed oil, peanut oil, soybean oil, millet oil and lard oil are determined. The results show that the content of unsaturated fatty acids is normally higher than that of the satu- rated fatty acids. In tested oils, the content of linoleic acid in soybean oil is the highest, up to 60. 02%. The content of unsaturated fatty acids in vegetable oil is higher than that in lard oil,while in millet oils up to 84. 33% ,and in lard up to 50. 43%.