实验室土壤质控样品重金属测试结果允许相对误差判据研究

Study on allowable relative error criteria for heavy metal in laboratory soil quality control sample

实验室内部质控体系对于维护检测实验室正常运转具有重要意义。定期核查质控样品分析结果并进行准确度评估,是质控体系正常运行的基本要求。合理选择评估判据是质控规范的重要内容。论文以土壤、沉积物系列标准样品中土壤详查目标重金属元素(As、Be、Cd、Co、Cr、Cu、Hg、Mo、Mn、Ni、Pb、Sb、Tl、V、Zn等)含量认定值及扩展不确定度数据为基础,利用非线性拟合工具,建立了目标元素允许相对误差经验模型,探讨并提出了实验室内部质控样品重金属元素分析结果合格性新判据,并与目前正在执行的地质部门质控规范和生态环境部相关质控技术规定进行了比较。提出的技术途径对于正在修订的地质部门实验室质控规范具有参考价值。

The internal quality control system of laboratory is of great significance to maintain the normal operation of testing laboratory. The periodic verification of analysis results of quality control samples as well as accuracy evaluation is the basic requirement for the normal operation of quality control system. The reasonable selection of evaluation criterion is an important content in quality control specifications. Based on the certified values and expanded uncertainty data for the contents of target heavy metals (As, Be, Cd, Co, Cr, Cu, Hg, Mo, Mn, Ni, Pb, Sb, Tl, V and Zn, etc) in series standard samples of soil and sediment, the empirical model of allowable relative error for target elements was established using the nonlinear fitting tool. New criterion for the analysis results of heavy metal elements in internal quality control samples of laboratory was discussed and proposed. It was compared with the related quality control specifications which were being executed by the departments of geology and ecological environment. The proposed technological approach had reference value for the quality control specifications in laboratory which were being revised by department of geology.