火焰原子吸收法测土壤中铜的不确定度评定

Evaluation of uncertainty in determination of copper in soil by Flame Atomic Absorption Spectrometry

本文的研究目的是提高实验室按照标准方法测定土壤中重金属含量的准确性,研究方法是依据《土壤和沉积物铜、锌、铅、镍、铬的测定火焰原子吸收分光光度法》(HJ491-2019)标准规定的测试方法,采用电热板消解土样,对土壤中的铜进行测定,同时结合试验过程、数学模型,分析该测量不确定度的可能来源,计算各个因素相关的不确定度分量,并将各分量进行合成计算,评定整个实验过程的测量不确定度。结果:影响土壤中重金属铜测量不确定度的主要因素为样品的重复测定,其次是工作曲线拟合和标准溶液的配置。本文可以指导检测员加强这方面学习,提高检测水平,同时为质量部门加强和提升质量控制提供了方向。

Objective: to improve the accuracy of laboratory determination of heavy metals in soil according to standard methods. Methods: according to the test method specified in the standard hj491-2019 “determination of copper,zinc,lead,nickel and chromium in soil and sediment flame atomic absorption spectrophotometry”,the soil sample was digested by electric heating plate,and the copper in the soil was determined. At the same time,combined with the test process and mathematical model,the possible sources of the measurement uncertainty were analyzed,the uncertainty components related to various factors were calculated,and the components were synthesized,Evaluate the measurement uncertainty of the whole experimental process. Results: the main factors affecting the uncertainty of the measurement of heavy metal copper in soil are the repeated determination of samples,followed by the fitting of working curve and the configuration of standard solution,which can guide the inspectors to strengthen their study in this regard and improve the detection level. And provide directions for the quality department to strengthen and improve quality control.