摘要
研究了棉油甲酯在碘的催化下发生异构化反应的规律 ,运用气质联用仪和紫外光谱对异构化产物的成分进行了分析。在最佳的异构化条件下 ,异构化棉油甲酯中共轭亚油酸质量分数可达 31.2 % ,共轭转化率 5 6 % ;根据不同质量浓度样品的紫外吸收曲线找出样品质量浓度与吸光度之间的线性关系 ,并参照气质联用分析的共轭亚油酸质量分数结果 ,得出紫外光谱法分析计算异构化产物中共轭亚油酸质量分数的经验公式为 :ω(CLA) =0 .0 0 80 1A/C ,吸光系数为 0 .0 0 80 1,适宜的质量浓度为 0 .0 2～ 0 .0 4g/L ,误差小于 5 %。实验证实紫外光谱法是分析测定棉油甲酯异构化产物中共轭亚油酸的一种简便。
The isomerization of methyl ester of cottonseed oil under the catalyst iodine was investigated.By the methods of GC-MS and UV,the constituents of isomerized products were analyzed.Under the optimum isomerization conditions,mass fraction of conjugated linoleic acid in isomerized cottonseed oil methyl esters was 31.2%,and conversion of conjugation was 56%.UV absorbancy curve of measured samples at different concentration was plotted,and linear relationship of absorbancy and samples' concentration was determined.Combined the accurate concentration of conjugated linoleic acid by GC-MS,the empirical formula for the quantitation of conjugated linoleic acid in isomerized products was obtained,ω (conjugated linoleic acid) =0.00801·A/C.The absorbance constant was 0.00801,optimum mass concentration was 0.02～0.04 g/L,and error was less than 5%.The results show that UV is a simple and quick method for determination of conjugated linolleic acid in isomerized cottonseed oil methyl esters.
出处
《中国油脂》
CAS
CSCD
北大核心
2004年第6期24-26,共3页
China Oils and Fats
基金
中国科学院"西部之光"资助项目
关键词
棉籽油
异构化
棉油甲酯
共轭亚油酸
定量分析
气质联用仪
紫外光谱
cottonseed oil
isomerization
cottonseed oil methyl esters
conjugated linoleic acid
quantitative analysis
