电感耦合等离子体质谱分析大气颗粒中重金属离子含量的不确定度评定

Uncertainty evaluation of heavy metal ion content in atmospheric particles determined by inductively coupled plasma mass spectrometry

评定了电感耦合等离子体质谱法测定大气颗粒物中重金属离子镉和铅含量的不确定度。建立了微波消解-电感耦合等离子体质谱对PM_(10)中重金属离子含量测试的数学模型,对影响测试过程的各个要素进行了分析,讨论了各不确定度分量,包括测量重复性、溶液定容、标准工作曲线拟合、标准物质、称量和仪器稳定性等,并开展了不确定度合成计算和扩展不确定度计算。结果表明,当大气颗粒物样品中镉和铅的质量浓度测量值分别为0.026、0.251μg/m^(3)时,扩展不确定度分别为0.000462、0.0036μg/m^(3)(k=2)。该方法可为建立大气颗粒物中重金属离子的分析和评价方法提供参考依据。

The uncertainty of determination of heavy metal ions cadmium and lead in atmospheric particulate matter by inductively coupled plasma mass spectrometry(ICP-MS)was evaluated.A corresponding mathematical model for measuring heavy metal ion content in PM_(10) by microwave digestion and ICP-MS was established.The factors affecting the testing process were analyzed and discussed,and the uncertainty synthesis calculation as well the extended uncertainty calculation were carried out.The results showed that when the mass concentrations of cadmium and lead in atmospheric particulate samples were 0.026μg/m^(3) and 0.251μg/m^(3),the extended uncertainties were 0.000462μg/m^(3) and 0.0036μg/m^(3),respectively(k=2).This method provided a reference for the analysis and evaluation of heavy metal ions in atmospheric particles.