液相色谱-串联质谱法准确定量植物油中主要甘油三酯

Quantification of major triglycerides in vegetable oils by liquid chromatography-tandem mass spectrometry

植物油中甘油三酯种类众多、结构复杂,准确定性定量非常困难。本文采用液相色谱-串联质谱法,选择反应监测扫描模式下,两对离子对定性、外标法准确定量植物油中七种主要甘油三酯,包括:三亚油酸甘油酯(LLL)、1-油酸-2,3-亚油酸甘油酯(OLL)、1-棕榈酸-2,3-亚油酸甘油酯(PLL)、1-棕榈酸-2-油酸-3-亚油酸甘油酯(POL)、三油酸甘油酯(OOO)、1,2-油酸-3-棕榈酸甘油酯(OOP)、1-棕榈酸-2-油酸-3-硬脂酸甘油酯(POS)。使用反相色谱柱分离甘油三酯,以异丙醇/乙腈混合溶液和乙腈/水混合溶液为流动相梯度洗脱,15 min内可实现甘油三酯的分离与检测。该方法线性关系良好,均在0.996以上,检出限为0.3μg/kg,定量限为1.0μg/kg,精密度(RSD)为1.2%~4.9%。该方法操作简单、快速,能够实现菜籽油、玉米油、花生油中七种甘油三酯的准确定量。

There are many types of triglycerides in vegetable oils,and their structures are complex,which is difficult to quantify with certainty.This paper used liquid chromatography-tandem mass spectrometry,selective re⁃action monitoring(SRM)mode,two pairs of ion pairs for qualitative,external standard method to accurately quantify seven major triglycerides in vegetable oils,including:glyceryl trilinolein(LLL),1-oleic acid-2,3-linoleic acid glyc⁃eride(OLL),1-palmitic acid-2,3-linoleic acid glyceride(PLL),1-palmitic acid-2-oleic acid-3-linoleic acid glyc⁃eride(POL),glyceryl trioleate(OOO),1,2-oleate-3-glycerate glyceride(OOP),1-palmitic acid-2-oleic acid-3-stearic acid glyceride(POS).The triglycerides were separated by reversed-phase chromatography,and the isopropyl alcohol/acetonitrile mixed solution and acetonitrile/water mixed solution were used as mobile phase gradient elu⁃tion.The triglyceride could be separated and detected within 15 minutes.This method has a good linear relation⁃ship,all above 0.996,with a detection limit of 0.3μg/kg,a limit of quantification of 1.0μg/kg,and a precision(RSD)of 1.2%to 4.9%.The method is simple and fast to operate,and it can be used to detect the seven triglycerides in vegetable oils such as rapeseed oil,corn oil,and peanut oil.