电感耦合等离子体质谱法测定烟草中镉的不确定度评定

Evaluation of Uncertainty in Determination of Cadmium in Tobacco by Inductively Coupled Plasma Mass Spectrometry

[目的]对电感耦合等离子体质谱法(ICP-MS)测定烟草样品中的镉含量的不确定度进行评定。[方法]通过分析测试过程,确定了各测量不确定度分量,建立了ICP-MS测定烟草中镉的不确定度方法。[结果]试验表明,镉测量结果的合成标准不确定度为0.020mg/kg;当k=2,置信水平为95%时,扩展不确定度为0.040 mg/kg;且样品浓度测量是该不确定度的主要来源。[结论]研究可为准确评价烟草中重金属检测结果提供参考。

[ Objective] The uncertainty in the determination of Cadmium（Cd） in tobacco by inductively coupled plasma mass spectrometry （ICP-MS） was evaluated in this paper. [ Method] By analyzing the determination process, the components of various measurement uncertainties was ascertained and the evaluation method of uncertainty was established. [ Result] The results showed that the combined standard uneertainty of Cd measurement results was 0. 020 mg/kg. Under the conditions of k = 2 and α = 0.05, the expanded uncertainty of Cd was 0.040 mg/kg. Concentration of the tested samples is the main source of uncertainty. [ Conclusion] The study can provide reference for accurate evaluation of heavy metals determination in tobacco.