超声波辅助萃取同位素稀释质谱法测定聚氯乙烯中6种邻苯二甲酸酯

采用超声波辅助萃取同位素稀释质谱法测定聚氯乙烯中6种邻苯二甲酸酯的含量。以四氢呋喃为溶剂对样品进行超声波辅助提取后，加入甲醇对聚合物进行沉淀，取上清液，经冷冻离心后进行气相色谱一质谱分析，并采用氘代邻苯二甲酸酯为内标，单点校正法定量。该方法应用于中、日、韩计量比对的样品测定中，两天进行的6次测定结果相对标准偏差为0．7％～3．0％。最终比对结果显示3个国家的数据取得很好的一致性，除DEP相对标准偏差为2．4％以外，其它5种邻苯二甲酸酯相对标准偏差为0．7％～1．2％，测定结果的相对扩展不确定度为1．8％～4．9％，证明该方法准确、可靠。

Determination of Six Phthalates in PVC by Sonication Assisted Extraction / IDMS

A method was developed to simultaneously determine 6 kinds of phthalates in polyvinyl chloride（PVC） by isotope dilution GC-MS. The sample was extracted by tetrahydrofuran with sonication assist and methanol was added to precipitate PVC polymer, then the supernatant was freeze centrifuged and analyzed by GC-MS. Deuterated phthalates were used as internal standard, and single point calibration was used as quantitative method. The method was used in the compar- ison of metrology laboratories of China, Japan and Korea, and the relative standard deviation（RSD） of six replicates during two days was 0.7%-3.0%. The comparison result showed well agreement of all values from the three laboratories, RSD of DEP was 2.4% and the RSD of other five phthalates was 0.7%-1.2%. The relative expanded uncertainty of six phthalates was 1.8%-4.9%, accuracy and reliability of the determination method were confirmed as well.