茶叶中铜含量测定的不确定度评定

Uncertainty Evaluation of Measurement Results for the Determination of Copper in Tea

[目的]评定茶叶中铜含量测量结果的不确定度,为原子吸收光谱法测定其他金属元素的不确定度分析提供参考。[方法]利用火焰原子吸收法对测定茶叶中铜含量的测量不确定度进行评定。[结果]在茶叶样品铜含量的测定中,铜含量为18.2μg/g,其扩展不确定度为0.95μg/g(置信度95%,k=2)。[结论]影响茶叶中铜含量测量结果不确定度的最大因素是拟合曲线引入的不确定度。

[Objective]The research aimed to evaluate the uncertainty of measurement results for the determination of copper in tea,and to provide references for the analysis on uncertainty of other metal element determined by AAS.[Method]The copper content in tea was determined by flame atomic absorption spectrometer according to the national standards.[Result]The results showed that in this analysis,the expanding uncertainty is 0.95 μg/g（degree of confidence of 95%,k=2） with copper content of 18.2 μg/g.[Conclusion]The introduce of fitting curve was the highest element affected the uncertainty of measurement results for the determination of copper in tea.