建立了高效液相色谱-串联质谱法（HPLC-MS/MS）同时测定塑料类食品接触材料制品中邻苯二甲酸二（2-乙基）己酯（DEHP）及其间位（DOIP）和对位同分异构体（DOTP）的特定迁移量。准确移取1.00 mL的10%乙醇、3%乙酸、4%乙酸、20%乙醇、50%乙醇或异辛烷浸泡液试样至10 mL容量瓶中，用异丙醇定容至刻度混匀，过针头式滤膜至进样瓶中，待测。以甲醇和0.1%甲酸水为流动相，DEHP、DOIP和DOTP在C₁₈柱中16 min内达到基线分离，串联质谱在ESI和MRM模式下进行检测。在聚丙烯（PP）塑料杯的4种代表性食品模拟物浸泡液中，DEHP、DOIP和DOTP在3个加标水平下的加标回收率范围为83.8%~113.0%，RSD范围为1.4%~8.3%，在0.010~0.200、0.100~2.000、0.500~10.000 µg/L质量浓度范围内线性相关系数R≥0.999 4，定量限分别为0.020、0.300、1.300 mg/kg。该方法快速、简便、准确性好，定量限符合标准法规要求，可以有效规避限量不同但质谱确证离子对相似的同分异构体由于色谱分离不完全而导致的检测结果混淆性错误。该方法已用于实际样品中DEHP、DOIP和DOTP的检测。

A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the simultaneous determination of the specific migration amounts of di(2-ethylhexyl) phthalate (DEHP), di(2-ethylhexyl) isophthalate (dioctyl isophthalate, DOIP) and di(2-ethylhexyl) terephthalate (dioctyl terephthal, DOTP) in plastic food contact material and products. 1.00 mL of the well-mixed 10% ethanol, 3% acetic acid, 4% acetic acid, 20% ethanol and 50% ethanol or isooctane soaking solution sample of plastic food contact material products was accurately pipetted into a 10 mL volumetric flask, the volumetric flask was made up to the mark with isopropanol and mixed well, and then the solution of the volumetric flask was passed through a needle filter membrane into an injection vial for testing. Using methanol and 0.1% formic acid water as mobile phases, the baseline separations of DEHP, DOIP and DOTP were achieved in a C₁₈ column within 16 minutes, and the tandem mass spectrometry was operated in ESI and MRM modes. In the food simulant soaking solutions of 10% ethanol, 4% acetic acid, 50% ethanol or isooctane of polypropylene (PP) plastic cups, the recovery rates of DEHP, DOIP and DOTP at three spiking levels were ranged from 83.8% to 113.0%, with relative standard deviations (RSDs) from 1.4% to 8.3%. The linearities of DEHP, DOIP and DOTP were good with R≥0.999 4 in the concentration range of 0.010~0.200, 0.100~2.000, 0.500~10.000 µg/L respectively, and the quantitative limits of DEHP, DOIP and DOTP were 0.020, 0.300, 1.300 mg/kg respectively. The method is fast, simple and accurate, and the quantitative limits also meet the requirements of standards and regulations. It can effectively avoid the confusing errors in detection results caused by incomplete chromatographic separation of isomers with different limits and similar mass spectrometry confirmation ion pairs. It has been applied in the detection of DEHP, DOIP and DOTP in actual samples.