用Horwitz经验模型评估环境监测分析方法标准再现性标准偏差数据合理性  

Evaluation for rationality of the reproducibility standard deviation in environmental monitoring analysis methods standard with Horwitz empirical model

作　　者：郭超 张百慧 范爽 殷惠民 李玉武[1,2,3] GUO Chao;ZHANG Baihui;FAN Shuang;YIN Huimin;LI Yuwu(Guohuan Oasis(Gu'an)Environmental Technology Co.,Ltd.,Langfang 065500,China;Environmental Development Centre of the Ministry of Ecology and Environment,Beijing 100029,China;National Research Center for Environmental Analysis and Measurements,Beijing 100029,China)

机构地区：[1]国环绿洲(固安)环境科技有限公司,河北廊坊065500 [2]生态环境部环境发展中心,北京100029 [3]国家环境分析测试中心,北京100029

出　　处：《冶金分析》2021年第6期27-34,共8页Metallurgical Analysis

基　　金：国家重点研发计划(2016YFC0208104)。

摘　　要：再现性标准偏差(sR)是分析方法基本性能参数之一,构成方法标准中再现性限基础。对应于不同浓度的再现性限是日常质控规范重要依据之一。以环境监测领域土壤、沉积物及固废样品中无机元素不同分析方法标准为例,用Horwitz经验模型(Ⅱ类)和H判据(实验统计值sR与模型计算值之比),考察了已颁布执行的标准文本和正在生态环境部官网公开征求意见的方法验证报告中再现性标准偏差的合理性。研究结果表明,H>4和H<0.5是普遍存在的现象。当H>4时,它提示:(1)参与统计计算的数据中可能存在“异常值”;(2)数据中可能存在“双峰”现象,sR数据已偏离正常值范围。当H<0.5时,它提示实验数据精密度是否过于乐观,是否存在不应删除的数据。异常值识别过程可以结合日常质控规范和H值是否处于正常区间进行综合判断。用来自方法验证报告的原始测量数据为例解释了异常值识别过程。为避免直接导致sR偏低的各种人为因素的干扰,精密度验证实验应尽量采用实际(土壤、沉积物、固废)样品。采用标准样品时,不应要求上报结果一定要位于标样认定值不确定度区间,满足日常质控规范就可以认为是符合要求。采用密码编样也是有效避免人为干扰的有效途径。Horwitz经验模型及H判据是快速核查再现性标准偏差数据合理性的有用工具。The standard deviation of reproducibility(sR)was one of the basic performance parameters of the analytical method,and it was the basis to calculate the reproducibility limit in the method standard.The reproducibility limit of different concentration was one of important basis for daily quality control specifications.Taking the standard texts for different analysis methods of inorganic elements in soil,sediment and solid waste samples in the field of environmental monitoring as an example,the Horwitz's empirical model(II)and H criterion(the ratio of experimental statistical value sR to calculated value of the model)were used to examine the rationality of the reproducibility standard deviation in the standard text that had been published and implemented,and method validation report for public comment and advice published in the official website of the Ministry of Ecology and Environment.It was showed that H>4 and H<0.5 were common phenomena.When H>4,it implied:(1)there might be"outliers"in the data involved in statistical calculation;(2)there might be"double peaks"in the data,and sR data had deviated from the normal range.When H<0.5,it implied:whether the precision of the experimental data was too optimistic,and whether there were data that should not be deleted.The outlier in the data could be judged by combining the daily quality control specifications and the fact that whether the H value was in the normal range.The raw measurement data from the method verification report was used as examples to explain the identification process of outliers.In order to avoid the interference of various human factors those directly leaded to lower sR,the actual(soil,sediment and solid waste)samples should be used as much as possible in precision verification experiments.When certified reference materials was selected,it was not required that the reported results must be located in the uncertainty interval of the certified value of certified reference materials,and it was considered as meeting the requirements for satisfying the

关 键 词：Horwitz检验模型 土壤 沉积物 固废样品 无机元素 分析方法 再现性标准偏差 

分 类 号：O657[理学—分析化学] X83[理学—化学]