同位素稀释质谱法测定聚丙烯塑料中Pb的含量

采用同位素稀释电感耦合等离子体质谱法（ID—ICP-MS）测定了聚丙烯塑料中Pb元素的含量。样品处理采用高压密封焖罐酸溶样技术，将样品与^207Pb稀释剂混合，通过所加稀释剂的量和测量混合样品中^208Pb/^307Pb的丰度比，准确计算出样品中Pb元素的含量，同时对测量结果的不确定度进行了分析和评定。该方法与传统方法相比具有准确性高、不确定度小、受外界污染及样品损失影响小等优势，适用于国家计量单位对标准物质进行定值。

Determination of Pb content in polypropylene with ID-ICP-MS

Pb content of polypropylene sample was determined by isotope dilution ICP-MS. The sample was digested with the solvent HNO3/H2O2 in high-pressure vessel, and it was mixed with isotope dilution ^207Pb. Then, the Pb content could be determined through measuring the spike addition and the ratio of ^308Pb/^307pb. Also, the measurement uncertainty was analyzed and evaluated. Comparing with traditional method, this method indicates good accuracy and small uncertainty. And the interference and Pb loss during the pretreatment process have less impact on this method. Thus, it is more suitable for reference material certifications of national metrology institutes.