饮用水中铁检测的能力验证研究

Proficiency test for determination of iron in drinking water

目的通过能力验证计划,对全国实验室饮用水中铁检测能力进行分析和评价。方法能力验证计划项目中使用的被测样品参考二级标准物质制备方法制备,分别采用单因子方差分析法(F检验法)、线性拟合趋势分析法、平均值一致性检验法(t检验法)对其进行均匀性检验、稳定性检验及模拟运输短期稳定性检验。在采用核密度图法检验实验室检测结果分布情况基础上,对实验室检测结果进行迭代稳健统计分析,采用Z值评定各参加实验室的检测结果。结果全国共1010家实验室参加该项能力验证计划项目,获得满意结果的实验室928家,结果满意率为91.9%,可疑结果的有19家,结果可疑率为1.9%,离群结果的有63家,结果离群率为6.2%。结论能力验证统计结果表明,国内实验室饮用水中铁检测能力总体较好,少部分实验室的检测能力有待改进提高。

OBJECTIVE To evaluate the capacity of national laboratories for determination of iron in drinking water using Proficiency Testing Program.METHODS The preparation method of the Secondary Standard Materials were used as the reference for the sample preparation in this Proficiency Testing Program.The homogeneity and stability of the samples and short-term stability for simulated transportation were tested by Single Factor Analysis of Variance(ANOVA)and Linear Regression and Mean consistency test.The result provided by participant laboratories were analyzed by robust statistics and assessed using the Z-score.RESULTS A total of 1010 laboratories throughout the country participated in the Proficiency Testing Program.928 laboratories,or 91.9%of total participating laboratories,obtained satisfactory result.Results provided by 19 laboratories,or 1.9%of total participating laboratories,were found to suggest doubts in their capacities.Finally,there were 63 laboratories,constituting 6.2%of total participating laboratories,with result that were found to be outliers.CONCLUSION The capacity of national laboratories for determination of iron in drinking water has been ranked as satisfactory according to statistical analysis of the Proficiency Testing Program result.Only a small portion of the participants require further improvement in their capacities.