石墨炉原子吸收法测定茶叶中铅的不确定度分析

Analysis of uncertainty in determination of Pb in tea by graphite furnace atomic absorption

目的通过石墨炉原子吸收法测定茶叶中的铅不确定度。方法根据《测量不确定度评定和表示》中的方法和公式,对该方法的不确定度进行分析。结果标准曲线方程引入的不确定度是0.015 8,电子天平称量引入的不确定度是0.000 16,重复测定样品引入的不确定度是0.015 5,样品消化液定容体积引入的不确定度是0.000 74,标准储备溶液引入的不确定度是0.001 5,标准溶液稀释过程中体积引入的不确定度是0.014 4。结论标准曲线方程引入的不确定度对检测结果的影响最大。

[ Objective] To determine the uncertainty of Pb in tea by graphite furnace atomic absorption. [ Methods ] According to the methods and formulas of ＂ Uncertainty in Measurement and representation ＂, the uncertainty of the method was analyzed. [ Results] The analysis showed the uncertainty introduced by standard curve equation was 0. 015 8, 0.000 16 of electronic weighing scales, 0.015 5 of repeated determination of the sample, 0.000 74 of sample digestion liquid volume, 0. 001 5 of standard stock solution, 0. 014 4 of standard solution dilution volume in the process. [ Conclusion ] The uncertainty introduced by standard curve e- quation possesses the maximum effect on the test results