高效液相色谱-蒸发光散射检测器测定食品中胆固醇含量

Determination of Cholesterol in Foods by HPLC with Evaporative Light-Scatter Detector

建立了可满足各类食品（包括动物性食品、动植物混合食品）中胆固醇的HPLC—ELSD快速测定方法。样品经50％（w）KQH直接皂化和石油醚萃取后进行色谱分析。色i普柱为ODS柱，流动相为乙醇和乙脯，通过优化梯度洗脱条件，在20min内实现了胆固醇与干扰物质（如植物甾醇）的有效分离，分离度月大于1．5。胆固醇色谱峰面积的自然对数与浓度的自然对数呈良好的线性关系（r〉0．9996），检出限（LOD）为0.20μg（S／N=3），定量下限（LOQ）为0．56μg（S／N=10），回收率为93％-96％（n=6），重复性RSD〈3．0％（n=6）。

A simple, rapid and accurate method was developed for determination of cholesterol in a variety of foods, including animal and plant originated foods, by high performance liquid chromatography （HPLC） with evaporative light -scatter detector （ELSD）. After directly saponified with 50% （w） KOH, the sample was extracted with petroleum ether. The extract was then separated on an ODS column and eluted by mobile phases consisted of ethanol and acetonitrile with a gradient program. Cholesterol was separated satisfactorily with interferences such as phytosterols in 20 minutes with R 〉 1.5. The logarithm of peak areas of cholesterol was plotted against the logarithm of the concentration of standard solutions, and a linear regression coefficient of 0. 999 6 was obtained in the range of 20 - 1 200 mg/L. Limit of detection（LOD） was 0. 20 μg（ S/N = 3 ） and limit of quantification（LOQ） was 0.56 μg（ S/N =10）. Recoveries of 93%- 96% （n = 6） were obtained by spiking experiments. The repeatability （ RSD, n = 6） of the method was less than 3.0%.