石墨炉-原子吸收法测定饮用纯净水中 铅含量的不确定度

Uncertainty of determination of plumbum in purified water by graphite furnace atomic absorption spectrophotometry

中文关键词:  石墨炉  原子吸收光谱法  铅  不确定度

英文关键词:graphite furnace  atomic absorption spectrophotometry  plumbum  uncertainty

中文摘要:

      目的 评定石墨炉-原子吸收法测定饮用纯净水中铅含量的不确定度。方法 分析影响饮用纯净水中铅含量测定的各种影响要素, 包括标准溶液、标准溶液稀释过程、原水样的体积、待测水样的体积、标准曲线拟合和测量结果重复性等, 并进行定量评定。结果 本方法测量的合成不确定度为3.01%, 扩展不确定度为6.02%。本方法测量饮用纯净水中铅含量的结果为(5.347±0.322) ng/mL(k=2, 置信区间95%)。结论 通过对本方法的不确定度评定, 掌握引入不确定度的主要因素, 降低可控不确定度对实验结果的影响, 提高实验结果的准确性。

英文摘要:

      Objective To evaluate the uncertainty of determination of plumbum in purified water by graphite furnace atomic absorption spectrophotometry. Methods The influencing factors of determination of plumbum content in purified water were analyzed, including standard solution, the dilution process of standard solution, the volume of water sample, the volume of water sample tested, standard curve fitting and the repeatability of testing results and so on, which were quantitatively evaluated. Results The synthetic uncertainty was 3.01%, and the expanded uncertainty was 6.02%. The results of plumbum content was (5.347±0.322) ng/mL (k=2, CI=95%). Conclusion By evaluation of uncertainty of the experiment methods, the main factors which give rise to uncertainty are grasped. It can be used to reduce the influence of controllable uncertainty so as to improve the accuracy of experiment results.