石墨炉原子吸收法测定饮用水中镉的不确定度分析

【目的】通过对饮用水中镉含量的测定,研究石墨炉原子吸收法测水中镉(GB/T 5750.6—2006)不确定性因素的影响。【方法】通过建立数学模型,研究测试结果分散性与测量结果参数的联系,以及测量结果不确定的来源。【结果】该饮用水中镉含量测定值为(0.005±0.000 2)mg/L(k=2),测定值的不确定主要与测试的重复性、标准物质、玻璃器皿、标注曲线拟合等因素有关。【结论】此方法可用于评估按照GB/T 5750.6-2006测定饮用水中镉含量的不确定度。

Uncertainty Analysis in Determination of Cadmium in Drinking Water by Graphite Furnace Atomic Absorption Spectrometry

Objective] The influence of Cadmium (GB/T 5750.6-2006) on the uncertainty of water in Graphite was studied by the determination of Cadmium in drinking water by Graphite Furnace Atomic Absorption Spectrometry method.Methods] The mathematical model was established,the quantitative component of uncertainty was analyzed in the measurement process, combined standard uncertainty and expanded uncertainty were calculated,and the sources of uncertainties in the measurement results were studied.Results] The determination of Cadmium in drinking water was (0.005±0.000 2) mg/L(k=2).The uncertainty of the measured values was mainly related to the reproducibility of the test, the standard substance, the glassware, the calibration curve related.Conclusion] This method is suitable for assessing the uncertainty of Cadmium content in drinking water according to GB/T 5750.6-2006.