正相液相色谱法测定婴幼儿配方乳粉中1，3-二油酸-2-棕榈酸甘油三酯

摘要

Methods for the determination of 1,3-dioleoyl-2-palmitoyl triglyceride ( OPO ) in infant formula milk powder by normal-phase liquid chromatography ( NP-LC ) and reversed-phase liquid chromatography( RP-LC ) were established and compared. The analytes in the infant formula were extracted by ethyl ether and petroleum ether,enriched by a rotary evapora-tor,and separated on silver-ion column and C18 column and detected with an evaporative light scattering detector( ELSD). OPO and 1,2-dioleoyl-3-palmitoyl triglyceride( OOP)can be basi-cally separated on a silver-ion column with a mixed solution of dichloromethane-acetone as mobile phase by gradient elution. The recoveries were 93. 0%-101. 5%,the relative standard deviations( RSD)were 2. 89%-4. 56%,and the limit of detection was 20 mg/kg. This method is accurate and stable for the determination of OPO in the infant formula milk powder.%建立并比较了正相色谱与反相色谱测定婴幼儿配方乳粉中1，3-二油酸-2-棕榈酸甘油三酯的方法。利用乙醚和石油醚提取婴幼儿配方乳粉中的油脂，经旋转蒸发浓缩后，分别采用银离子色谱柱和 C18色谱柱，配合蒸发光散射检测器检测。其中采用银离子色谱柱以二氯甲烷-丙酮为流动相梯度洗脱的正相色谱法完全分离了1，3-二油酸-2-棕榈酸甘油三酯（OPO）和1，2-二油酸-3-棕榈酸甘油三酯（OOP）两种同分异构体，方法的重复性和线性关系良好，回收率为93.0％～101.5％，精密度（ RSD）为2.89％～4.56％，检出限为20 mg／kg。该方法可准确测定婴幼儿配方乳粉中 OPO的含量。