油菜籽油分及脂肪酸同时测定的气相色谱快速方法

STMULTANEOUS DETERMINATION OF OIL CONTENT AND FATTY ACID CONTENT IN RAPE SEEDS BY GAS CHROMATOGRAPHY

本文拟定了对菜籽油分与脂肪酸组分同时测定的气谱快速方法,基于使用氢氧化四甲铵为催化剂,酯交换在汽化室以热解方式进行,可使油分定量地转换成脂肪酸甲酯。甲酯总峰面积的大小,可作为含油量的量度,与外标作比较,求得菜籽的含油率;再对各脂肪酸甲酯的峰面积作归一化法处理,便可求得各脂肪酸的含量;与油重法和IUPAC庚烷法测定结果相比较,其相对误差分别为±3％和±3—10％,符合快速分析的要求。

A rapid gas chromatographic method for simultaneously determining the oil and fatty acid content in rape seeds by a tetramethy-ammonium hydroxide as catalyser was achieved.The transesterification reaction was proceeded in injection port through pyrolysis from oil quantitative into methyl fatty acid esters.The magnitute of total peak areas of the esterscould be used as a measure of the amount of the oil and the oil contentin comparing with an external standard,and then,the fatty acid content could be calculated by normalization of the peak area of each ester.Therelative errors of these determinations were±3% and±3-10% respectively in comparison with pant oil extraction standard method and IUPACheptane method; and satisfied the demand for a rapid analysis.