正相超高压液相色谱法测定植物油中的维生素E

采用正相超高压液相色谱法测定油脂中4种常见生育酚的含量,确定一种简单、准确、快速测定维生素E的测定方法.样品经前处理后,用Zorbax RX-SIL硅胶柱分离,以乙酸乙酯-异辛烷为流动相梯度洗脱,在波长295nm采用外标法检测α、β、γ、δ等四种生育酚在不同植物油中的含量.研究结果表明,该方法四种异构体均在8min内出峰,线性关系在0.9994～0.9999间,精密度RSD＜5％,加标回收率在80％～100％,线性范围0.2～100.0μg/mL,α、β、γ、δ异构体方法检出限均在0.01μg/g左右；几种典型植物油样品验证实验表明该方法体系具有快速、准确、分离度好等特点.同时比较了调和油和精炼地沟油维生素E含量差异,初步确定α-维生素E可能作为该类地沟油识别因子.

Determination of Vitamin E in Edible Plant Oil by Normal Phase Ultra Performance Liquid Chromatography

A simple extraction procedure using liquid-liquid extraction coupled with normal phase ultra performance liquid chromatography(NP-UPLC) to determine four tocopherols from vegetable oils was developed.Using Zorbax RX-SIL,α,β,γ,and δ tocopherols were separated by NP-UPLC within 10 min through degraded dilution conditions.The results demonstrated that the new method established in this paper had a linearity ranging from 0.9994 to 0.9999.Recovery of this method changed between 80% and 100% and RSD was below 5%.Linearity range of the method for quantify vitamin E was 0.2 to 100 μg/mL and limitation of detection of the method was about 0.01 μg/g.The assay was successfully applied to the analysis of several oil samples and find there significant difference in α-tocopherols content between regulatory oil and refined waster oil.We proposed α-tocopherols as a biomarker for distinguishing waster oil and the further study was undertaken.