高效液相色谱法测定食用油中邻苯二甲酸酯类污染物总量

Determination of total phthalates content in edible oil by HPLC

建立了检测食用油中邻苯二甲酸酯总量的高效液相色谱方法。采用皂化酸解工艺,将食用油中邻苯二甲酸酯转化为邻苯二甲酸,经正己烷萃取弃除脂肪酸,再用乙酸乙酯萃取邻苯二甲酸,旋转蒸发浓缩,用甲醇溶解,C18色谱柱分离,紫外检测器分析,流动相为甲醇-磷酸盐缓冲溶液(浓度25 mmol/L,pH 2.5)进行梯度洗脱,总流速为1 mL/min,测定邻苯二甲酸的含量,并进一步估算出邻苯二甲酸酯的总含量。所建立的方法相对标准偏差为2.67%～9.51%,回收率在79.12%～110.01%之间。该方法前处理简单,有利于大批量样品中邻苯二甲酸酯总量的检测,适用于初步判定食用油是否受到邻苯二甲酸酯的污染及其受污染程度。

A method for determining total phthalates content in edible oil was established. Presented method was based on saponification - acid hydrolysis of the phthalates to phthalic acid, followed by the selective extraction of fatty acid with n - hexane, then phthalic acid was extracted with ethyl acetate, and the extract was dehydrated and dissolved with methanol for HPLC analysis. The HPLC conditions were C18 column, methanol - phosphate buffer with 25 mmol/L and pH of 2.5 as mobile phase at a flow rate of 1 mL/min and ultraviolet detector. The results showed that the relative standard deviations （RSD）were 2.67% -9.51% by this method,and average recovery rates of phthalic acid were 79.12% - 110.01%. The method was simple and suitable to determine total phthalates content in mass samples, and could be used as preliminary method for estimation of sample burden with phthalates.