原子荧光光谱法测定土壤总砷的测量不确定度分析

Analysis of the Uncertainty of Measurement for the Determination of Total Arsenic in Soil by Atomic Fluorescence Spectrometry

目的:探讨氢化物原子荧光光谱法测定土壤样品中总砷的测量不确定度的方法。方法:用原子荧光光谱法对土壤样品中的总砷含量进行测定,分析与测量结果相联系的参数,依据JJF1059-2012要求,建立数学模式,从样品称量、样品消化定容、标准储备液配制标准曲线、标准曲线回归方程和样品重复测量5个方面进行测量不确定度的计算。结果:当土壤样品中总砷含量为10.5 mg/kg时其测量不确定度为1.6 mg/kg。结论:分析影响砷元素测定的多种因素,通过建立数学模式可对氢化物原子荧光光谱法测定土壤中砷元素的测量不确定度进行合理的评定。其中检测人员在标准曲线制备与土壤样品分析时,正确、规范的操作技能对测定结果有主要影响。

Objective ： To study the ways of the uncertainty of measurement for the determination of total Arsenic in soil by hydride atomic fluorescence spectrometry. Methods： The total arsenic in the soil samples was determined by hydride atomic fluorescence spectrometry with the parameter analyzed related to the measurement results. According to the requirements in JJF1059-2012, the mathematical model was established. The evaluation of the uncertainty of measurement was carried out in five aspects, such as sample weighing , sample digestion, standard reserve liquid preparation standard curve, standard curve regression equation and sample repeated measures. Results： When the total arsenic content in soil sample was 10.5 mg/kg,the uncertainty of measurement was 1.6 mg/kg. Conclusion： Based on the analy- sis of various factors affecting the determination of arsenic, and through the establishment of the mathematical model, the uncertainty of measurement for the determination of total arsenic in soil by hydride atomic fluorescence spectrometry can be reasonably evaluated. In the process of the standard curve preparation and soil sample analysis, it is considered for the inspectors that the correct and standard operating skills have a major impact on the determination results.