快速甲酯化-气相色谱法测试油脂组成

针对油脂脂肪酸成分的测定,建立了一套以四氢呋喃为共溶剂,经甲酯化后以气相色谱测定各甲酯含量,确定油脂中对应脂肪酸三酰甘油含量的快速甲酯化-气相色谱分析的的方法。该法可有效提高甲醇/油脂体系甲酯化反应速率和油脂转化率,提升分析测试速率和准确性,实现油脂成分快速测定。结果表明,本方法线性关系良好,精密度高,相对偏差RSD≤2.02%,四氢呋喃不影响气相色谱分析结果,3种典型组分3种不同浓度加标回收率在96.14%~103.45%之间,甲酯化过程三酰甘油转化率可达95%,可以准确的测定甲酯化反应液中各脂肪酸组成的含量。

The Rapid Determination of the Fatty Acid Content of Oil with Fast Methyl Esterification and Gas Chromatography

In this research, a rapid analysis method combining with methyl esterification reaction of oil/grease and gas chromatography detection of fatty acid methyl ester (FAME) was established to determine the content of varied fatty acid triglyceride ingredient in oil with tetrahydrofuran (THF) as cosolvent in methyl esterification process. The adding of cosolvent, THF, can enhance the intermiscibility between oil and methanol in reaction, increasing the reaction rate and oil conversion, promoting the reaction speed of methyl esterification process and accuracy of FAME analysis. The results show that this new combined method has a good linear relationship and high degree of precision in contrast to traditional analysis method. The adding of THF does not affect the analysis of FAME via gas chromatography. The relative standard deviations of such rapid combined method were no more than 2.02%, and the average addition standard recoveries of three typical fatty acid methyl esters, oleic acid methyl ester, stearic acid methyl ester, and palmitic acid methyl ester, were from 96.14% to 103.45%. The conversion of three typical triglyceride, oleic acid triglyceride, stearic acid triglyceride and palmitic acid triglyceride, can reach more than 95% in methyl esterification process. The actual fatty acid ingredient can be determined rapidly and accurately via this combined analysis method