ICP-AES法测定高纯氧化镧中稀土杂质的不确定度评定

摘要

Using high-purity lanthanum oxide as an example, the uncertainty of determination of rare earth impurities in high-purity lanthanum by ICP-AES method in GB/T18115.1-2006 was evaluated.The uncertainty components of the repetition of determination, the calibration curve fitting, the preparation of standard solution, the sample weighing ,the constant volume and the conversion factor were analyzed and evaluated.The results show that the repetition of determination component is 41.38%-72.46%, the calibration curve component is 26.88%-58.29%, the other components are less than 1%, and the expanded uncertainty is 0.0002%-0.0003%.The result of uncertainty evaluation in this paper is consistent with the practical application, and it has a good application value.It can also provide reference for uncertainty evaluation in the determination of other high purity rare earth products in the GB/T18115 series.%以高纯氧化镧为示例,评定了GB/T18115.1-2006中ICP-AES法测定高纯氧化镧中稀土杂质的不确定度.分析并计算了测量重复性、校准曲线线性拟合、标准溶液配制、样品称量、试液定容及换算系数引入的不确定度分量.结果表明:各稀土杂质测量重复性分量所占权重为41.38~72.46%,校准曲线分量所占权重为26.88~58.29%,其余分量均小于1%;且扩展不确定度均在0.0002%~0.0003%之间.本文进行的不确定度评定符合实际,有较好的应用价值,也可为GB/T18115系列标准中其它高纯稀土产品中稀土杂质测定的不确定度评定提供参考.