石墨炉原子吸收法测定空心胶囊中铬含量的不确定度分析

Uncertainty Evaluation of Determing Chromium Content in Vacant Capsules by Graphite Furnace-AAS

目的:评定石墨炉原子吸收法测定空心胶囊中铬含量的不确定度,找出影响不确定度的主要因素。方法:根据《测量不确定度评定与表示》(JJF1059-1999)有关规定分析不确定度的来源,利用回归方程进行不确定度的评定。结果:本实验中空心胶囊中铬的含量表示为0.24±0.03mg·kg-1(包含因子k=2)。结论:石墨炉原子吸收法测定空心胶囊中铬含量时,标准曲线计算铬含量产生的不确定度对总不确定度的影响最大。

Objective The present study was conducted to evaluate the uncertainty in determination of chromium （Cr） in vacant cap-sules using graphite fumace-AAS and to find out the factors affecting the uncertainty. Methods The uncertainty source was analyzed and regression equation was applied for uncertainty evaluation according to JJF1059-1999. Results The content of Cr in vacant capsules was ,and the expanded uncertainty was （k=2）. Conclusion When the Cr content in vacant capsules was determined using graphite fur-nace-AAS, the uncertainty encountered in calculating Cr content using standard curve showed significant effects on Cr determination.