离子色谱法测定生活饮用水中氟化物的不确定度影响因素

目的建立离子色谱法测定生活饮用水中氟化物不确定度的评定方法,找出其主要影响因素。方法根据《生活饮用水标准检验方法无机非金属指标》(GB/T 5750.5—2006)建立数学模型,从样品重复测量过程、标准曲线校准过程、标准溶液稀释过程和标准系列配制过程来讨论各不确定度分量。结果 12次重复测定生活饮用水中氟化物含量均值为0.934 mg/L,其扩展不确定度为0.042 mg/L,k=2。结论标准系列配制过程对扩展不确定度的影响较大,是测量不确定度的主要影响因素。

Influencing factors of uncertainty in fluoride content determination in drinking water by ion chromatography

[ Objective ] To establish a method for uncertainty assessment of fluoride content in drinking water by ion chromatogra- phy, and identify the main influencing factors. [ Methods ] According ＂Standard Examination Methods for Drinking Water -Nonmetal Parameters＂ （GB/T 5750. 5-20061 , a mathematical model was set up, and the various components of uncertainty were determined by duplicate measurement of water samples, the calibration of standard curve, the dilution of standard solution and the preparation of standard series. [ Results] The average concentration of fluoride in drinking water was 0.934 mg/L with 12 times of duplicate survey, its expanded uncertainty was 0.042 mg/L （ k = 2 }. [ Conclusion] The most primary influencing factors to expanded uncer- tainty is the preparation of standard series in the measurement of uncertainty.