以氢化物一原子荧光法测定水中砷含量为例,应用不确定度理论,从测试过程和计算方法的角度分析了测量不确定度的各种影响因素:标准物质、溶液稀释情况、工作曲线的非线性以及原子荧光光度计的测量性能等,对各测量不确定度分量进行计算和评定.结果表明:原子荧光法测定水中砷含量的测量不确定度的主要影响因素是工作曲线的非线性和原子荧光光度计的测量性能,其次是标准储备液的逐级稀释,当水样稀释倍数非常低时,因水样稀释引入的不确定度可忽略不计.砷含量的扩展不确定度为1.2μg/L,置信水平为95％.%Determination of arsenic in water by hydride generation-atomic fluorescence spectrometry was taken for example in therntest. Effect factors on uncertainty were analyzed based on the theory of uncertainty determination from the angle of testing processrnand calculation method. The uncertainty caused by the certified reference material, diluted solution, standard curve,rnmeasurement performance of atomic fluorescence spectrometry and so on, and uncertainly was calculated and appraised. Thernresults showed that main effect factors on uncertainty of arsenic in water by hydride generation-atomic fluorescence spectrometryrnwere standard curve and measurement performance of atomic fluorescence spectrometry, gradual diluted standard stock solutionrnwas subordinate. When water sample dilution times were very Jow, the uncertainly caused by water sample dilution could bernignored. The expanded uncertainty of detection of arsenic in water by atomic fluorescence apectrometry was 1. 2 (xg/L under therncondition of 95% confidence level.
展开▼
