氢化物原子荧光法测定生活饮用水中砷含量的不确定度评定

The Uncertainty Assessment of Arsenic Content in Drinking Water by Hydride Generation Atomic Fluorescence Spectrometry

摘要:
目的建立氢化物原子荧光法测定生活饮用水中砷含量不确定度的方法评定，找出其主要影响因素。
方法依据《生活饮用水标准检验方法金属指标》(GB/T 5750.6-2006) 建立数学模型，从样品重复性测量、工作曲线校准、标准溶液稀释、配制以及样品量取等过程讨论不确定度分量。
结果当水样中砷浓度为6.12 μg/L时，其扩展不确定度为0.42 μg/L(k=2)。
结论标准溶液的稀释和配制过程引入的不确定度相对较大，是影响不确定度的主要因素。

Abstract:
Objectives To establish an assessment method of measuring uncertainty for arsenic content in drinking water by hydride generation atomic fluorescence spectrometry and to identify the main influencing factors.
Methods According to Standard Examination Methods for Drinking Water—Metal Parameters(GB/T 5750.6-2006), a mathematical model was set up and each of the uncertainty factor was discussed, such as repeated determination of water samples, the calibration of working curve, the dilution and preparation of standard solution and measuring the quantity of water sample.
Results When the arsenic content in drinking water was 6.12 μg/L, its expanded uncertainty was 0.42 μg/L(k=2).
Conclusion The items of the dilution and the preparation of standard solution are the major influencing factors of expanded uncertainty.