同位素稀释质谱法测定奶粉中痕量硒的不确定度评定

Uncertainty evaluation of determination of trace selenium in milk powder by isotope dilution mass spectrometry

中文关键词:  奶粉  硒  电感耦合等离子体质谱法  同位素稀释质谱法  不确定度

英文关键词:milk powder  selenium  inductively coupled plasma mass spectrometry  isotope dilution mass spectrometry  uncertainty

中文摘要:

      目的 评估同位素稀释质谱法(isotope dilution mass spectrometry, IDMS)测定奶粉中痕量硒含量的不确定度。方法 应用电感耦合等离子体质谱仪(inductively coupled plasma mass spectrometry, ICP-MS)通过IDMS测定奶粉消解液中痕量硒(Se)的含量, 建立该方法测量不确定度的评定模型并对其不确定度进行评判。结果 通过对前处理过程、测定方法流程进行分析, 确定不确定度的各个分量, 评定结果的不确定度以及扩展不确定度。计算得到样品中硒含量为0.1625 μg/g, 扩展不确定度为0.0118 μg/g, 扩展因子k=2。结论 该模型适用于IDMS法测定奶粉中痕量硒的不确定度评定, 为今后使用ICP-MS-IDMS法测定类似基体样品评定不确定度提供重要参考。

英文摘要:

      Objective To evaluate of uncertainty in the determination of trace selenium in milk powder by isotope dilution mass spectrometry (IDMS). Methods The content of trace selenium in milk powder was detected by inductively coupled plasma mass spectrometry (ICP-MS) with IDMS. The evaluation model of uncertainty in measurement was established and its uncertainty was evaluated. Results Through the analysis of the pretreatment process and the determination process, the uncertainty components, the uncertainty of the evaluation results and the expanded uncertainty were determined. As a result, selenium content in milk powder was 0.1625 μg/g, the expanded uncertainty was 0.0118 μg/g with the coverage factor k=2. Conclusion The model is suitable for evaluating the uncertainty in the measurement of selenium in milk powder with IDMS, which provides a valuable reference for similar matrix of samples to evaluate the uncertainty with ICP-MS-IDMS.