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

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。

Determination of 1,3-dioleoyl-2-palmitoyl triglyceride in infant formula milk powder by normal-phase liquid chromatography

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 evaporator, 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 basically 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.