用平行双样测定结果相对偏差限值评估方法验证实验重复性限合理性的研究

Study on Evaluation of the Rationality of Repeatability Limit by Relative Deviation Converting from Repeatability Limit Data in Analytical Method Performance Parameters

分析方法标准验证实验得到的分析方法基本性能参数重复性限和再现性限是日常检测工作质控规范重要依据。以环境监测领域土壤、沉积物及固废样品中无机元素分析为例,考察了已颁布执行的标准文本和在生态环境部官网公开征求意见的分析方法标准中重复性限。将重复性限转化为相对偏差后,与日常检测工作中质控限值进行了比较。根据目前现行有效的平行双样测定结果相对偏差限值,方法验证数据有多大比例符合质控要求?根据方法验证结果,平行双样测定结果相对偏差限值有无改进可能?从上述两个角度进行了研究。研究结果表明:土壤、沉积物、固体废弃物中无机元素的测定,不同文献来源相同分析方法标准和不同分析方法标准,其重复性限转化得到的平行测定相对偏差合格率存在明显区别;用平行测定相对偏差限值可以快速判断标准文本中的重复性限是否合理,审核方法验证数据质量是否满足要求。基于已有标准文本方法验证数据,探讨了修改平行测定结果相对偏差限值可行性。

The repeatability limit and reproducibility limit of the basic performance parameters of analytical methods obtained from the analytical standard verification experiment are the important basis for the quality control standard of daily detection work.Taking the analysis of inorganic elements in soil,sediment and solid waste samples in the field of environmental monitoring as an example,the repeatability limits as one of the analytical performance parameters were investigated from the standard text that has been promulgated and appeared in method verification report that is publicly soliciting comments on the official website of the Ministry of Ecology and Environment.After converting the repeatability limit into a relative deviation,it was compared with the quality control limit values used in routine analysis.The research work is based on the following two aspects:According to the current effective relative deviation limit in parallel determination,what proportion of the pass rate in method verification data that meets the quality control requirements.According to the method verification result,is there any improvement in the relative deviation limit of parallel determination?The results show that there are obvious differences between the pass rate of relative deviation of parallel determination obtained from the repeatability limit conversion of the determination of inorganic elements in soil,sediments and solid wastes,appeared in the same analytical method standard text from different literature sources and different analytical method standards text.The relative deviation limit of the parallel measurement can be used to quickly determine and check whether the repeatability limit in the standard text is reasonable,and the data quality appeared in there ports meets the requirements.Based on the verification data of existing standard text method,the feasibility of modifying the relative deviation limit of the parallel determination is discussed.