火焰原子吸收光谱法测定镁及镁合金中镉含量不确定度评定  

Evaluation of uncertainty of determination of cadmium content in magnesium and magnesium alloys by flame atomic absorption spectrometry

作　　者：张喜林 钱亚锋 Zhang Xilin;Qian Yafeng(National Quality Supervision and Inspection Center for Magnesium and Magnesium Alloy Products,Hebi 458030,China)

机构地区：[1]国家镁及镁合金产品质量监督检验中心,河南鹤壁458030

出　　处：《化学分析计量》2022年第3期83-87,共5页Chemical Analysis And Meterage

基　　金：河南省市场监督管理局科技计划项目(2021sj36)。

摘　　要：采用火焰原子吸收光谱法测定镁及镁合金中镉含量,对测定结果不确定度进行评定。建立数学模型,分析不确定度来源,计算合成标准不确定度和扩展不确定度。当镁及镁合金中镉含量为0.00418%时,其扩展不确定度为0.00034%(k=2)。火焰原子吸收光谱法测定镁及镁合金中镉含量不确定度主要来源于样品称量、样品消解溶液定容、标准工作溶液配制、绘制标准工作曲线和样品重复性测量,其中绘制标准工作曲线引入的不确定度对总不确定度贡献最大,通过优化标准工作曲线各拟合点,可减小测定结果不确定度,提高镁及镁合金中镉含量测定结果的准确度。The content of cadmium in magnesium and magnesium alloys was determined by flame atomic absorption spectrometry,and the uncertainty of the determination results was evaluated.A mathematical model was established,the source of uncertainty was analyzed,and the synthetic standard uncertainty and extended uncertainty were calculated.When the content of cadmium in magnesium and magnesium alloys was 0.00418%,the expanded uncertainty was 0.00034%(k=2).The uncertainty of the determination of cadmium in magnesium and magnesium alloys by flame atomic absorption spectrometry mainly comes from sample weighing,sample digestion solution sizing,standard working solution preparation,drawing standard working curve and sample repeatability measurement.The uncertainty introduced by drawing standard working curve contributes the most to the total uncertainty.By optimizing the fitting points of the standard working curve,the uncertainty of the determination results can be reduced and the accuracy of the determination results of cadmium in magnesium and magnesium alloys can be improved.

关 键 词：不确定度 火焰原子吸收光谱法 镉 镁及镁合金 

分 类 号：O657.3[理学—分析化学]