离子色谱法测定包装饮用水中的溴酸盐不确定度评定

目的评定离子色谱法测定包装饮用水中溴酸盐含量的不确定度。方法根据GB/T 5750.10-2006《生活饮用水标准检验方法消毒副产物指标》建立数学模型,参考JJF 1059.1-2012《测量不确定度评定与表示》对本方法的各个不确定度来源如标准溶液(包括标准物质、标准储备液配制、标准系列溶液配制)、测量结果重复性、最小二乘法拟合标准工作曲线等进行分析和量化。结果通过计算,水中溴酸盐含量测定的合成标准不确定度为0.000312 mg/L,扩展不确定度为0.0006 mg/L,测量结果表示为(0.0124±0.0006)mg/L(置信区间P=95%,k=2)。结论本方法的不确定度主要来源是标准曲线的拟合和标准系列溶液的配制。

Uncertainty evaluation for the determination of bromate in packaged drinking water by ion chromatography

Objective To evaluate the uncertainty of measurement in the determination of bromate in packaged water by ion chromatography. Method According to GB/T 5750.10-2006 Standard test methods for drinking water-Disinfection by-product indicators, a mathematical model was established. Referred to JJF 1059.1-2012 Evaluation and expression of uncertainty in measurement, various sources of uncertainty for the method, such as standard solutions (including standard materials, preparation of standard stock solutions, and preparation of standard series solutions), reproducibility of measurement results, and least squares fit to standard working curves, etc. were analyzed and quantified. Results By calculation, the uncertainty of the synthesis standard for the determination of bromate in water was 0.000312 mg/L, the expanded uncertainty was 0.0006 mg/L, and the measurement result was expressed as (0.0124±0.0006) mg/L (confidence interval P=95%, k=2). Conclusion The main sources of uncertainty for this method are the fitting of standard curves and the preparation of standard series solutions.