陕西省饮水氟砷测定实验室间质量控制结果与分析

Analysis of intellaboratory performance of determining fluoride and arsenic in drinking water in Shaanxi Province

目的评价实验室对饮水氟、砷分析的能力。方法参加实验室对2种质量浓度的氟、砷质控样品进行测定,采用方框图评价质控结果。结果对参考值为1．00、2．00 mg／L氟质控样品的测定结果分别为 (1．005±0．057)mg／L和(1．972±0．128)mg／L,室间相对标准差分别为5．0％和6．5％,室间相对误差分别为0．5％和1．4％;55个实验室中有50个合格,合格率为90．9％。对参考值为0．100、0．200 mg／L砷质控样品的测定结果分别为(0．098±0．022)和(0．196±0．043)mg／L,室间相对标准差为22．4％和21．9％,室间相对误差均为 2．0％;32个实验室中有29个合格,合格率为90．6％。结论通过饮水氟、砷测定室间质量控制,为陕西省饮水氟、砷筛查项目筛选出了合格的实验室。

Objective To analyze the intedaboratory performance of determining fluoride and arsenic in drinking water. Methods Concentrations of fluoride and arsenic in 2 samples were determined in participating laboratories for interlaboratory quality control, and the results were analyzed by means of square chart method. Results For fluoride samples （the reference concentration of fluoride being 1.00 mg/L and 2.00 rag/L, respectively）, the concentration determined was （1.005 ± 0.057）mg/L and （1.972 ± 0.128）mg/L, respectively; Interlaboratory relative standard deviation （RSD%） was 5.0% and 6.5%; Interlaboratory relative error was 0.5% and 1.4%, respectively; 50 out of 55 （90.9%） laboratories were rated as qualified. For arsenic samples （the reference concentration of arsenic being 0.100 mg/L and 0.200 mg/L, respectively）, the concentration determined was （0.098 ± 0.022） mg/L and （0.196 ± 0.043 ） mg/L, respectively ; Intedaboratory RSD% was 22.4% and 21.9% ; Interlaboratory relative error was 2.0% and 2.0%, respectively; 29 out of 32（90.6%） laboratories were considered as qualified. Conclusions Qualified laboratories were selected for survey of fluoride and arsenic in drinking water through interlaboratory quality control program in Shaanxi Province.