橄榄油甘油二酯异构体的HPLC-ELSD测定方法建立及其应用

Establishment and Application of HPLC-ELSD Method for Determination of Diacylglycerol Isomers in Olive Oils

目的:建立一种用于测定橄榄油中甘油二酯异构体的方法,并应用于评价橄榄油的新鲜度。方法:采用正相高效液相色谱法,以异丙醇-正己烷为流动相进行梯度洗脱,应用蒸发光散射检测器进行检测。结果:1,3-甘油二酯(1,3-DAG)和1,2-甘油二酯(1,2-DAG)在20 min内实现分离,分别在11.16~111.62 μg/mL和9.50~95.00 μg/mL范围内线性关系良好,平均回收率分别为103.2%和101.4%,重复性及日间精密度RSD均低于4.0%;应用该方法测定了6批特级橄榄油的甘油二酯异构体含量,测定结果与橄榄油氧化情况相关性较好。结论:该方法能够准确、快速地测定橄榄油甘油二酯异构体的含量。

Objective:To establish a method for the determination of diacylglycerol isomers in olive oils and its application in the evaluation of freshness of olive oils.Methods:Normal-phase high-performance liquid chromatography was used.Gradient elution was performed with isopropanol-n-hexane as the mobile phase.And the evaporative light scattering detector was used for detection.Results:1,3-Diacylglycerol (1,3-DAG) and 1,2-Diacylglycerol (1,2-DAG) were separated within 20 minutes.The linear relationships,ranging from 11.16 to 111.62 μg/mL and 9.50 to 95.00 μg/mL,are good.The average recoveries are 103.2% and 101.4%,respectively.And both repeatability and inter-day precision (RSD) values are below 4.0%.Using this method,the contents of diacylglycerol isomers in 6 batches of extra virgin olive oils were determined.The results are well correlated with the oxidation of olive oils.Conclusions:This method can accurately and quickly determine the contents of diacylglycerol isomers in olive oils.