基于稳健统计方法对实验室比对中土壤汞的质量控制指标研究

Quality Control Index on Inter-laboratory Comparison of Hg in Soil based on Robust Statistic Methods

利用稳健四分位间距法和迭代法2种稳健统计方法,通过对全国31个省、自治区、直辖市范围内共334家环境监测单位开展土壤中汞的实验室间比对,对比对测定结果和质控数据进行统计分析,系统性地研究了土壤中汞的质量控制指标。建议实际监测工作中土壤汞的实验室间相对标准偏差范围为7%～19%,相对误差控制指标为±8%,低浓度水平下可适当放宽至±10%,加标回收率控制范围为81%～109%,为日常监测开展土壤汞的质量控制工作提供了评价依据,具有广泛的应用价值和较好的指导作用。

Based on two robust statistic methods of quartile and iteration, inter-laboratory comparisons of Hg in soil was carried out in national environmental monitoring system in China, of which 31 provinces 334 laboratories were involved. The comparison test results and quality control data were analyzed, and then quality control index of Hg in soil was studied systemically. It was suggested that the inter-laboratory relative standard deviation of Hg in soil is between 7.3% and 19.1%, and the relative error is controlled within ±8%, which could be broadened within ±10% in our daily monitoring. The corresponding recovery rate can be ranged between 81% and 109%. This study might provide some evaluation basement for conducting actual quality control work on Hg in soil, which can be widely used in national monitoring.