EDTA法测定RECl3中稀土总量不确定度评价

Evaluation of Uncertainty for Total Rare Earth Content in RECl_3 Detected by the EDTA Method

采用EDTA滴定法测定混合氯化稀土RECl3溶液中稀土总量,建立相应的数学模型,对数学模型中各个参数进行不确定度来源分析。不确定度来源包括测量重复性、基准锌粒、体积、混合氯化稀土溶液平均摩尔质量等不确定度分量;依据不确定度的方法计算各不确定度的分量并合成和扩展,得测量结果的不确定度评定。结果表明:混合氯化稀土溶液中稀土总量可表示为:(306.02±1.73)g/L。

We took the method of EDTA titrimetry to determine the total rare earth content in mixed RE chloride, and built the corresponding mathematic model so as to analyze the uncertainty sources for each of the parameters in the model. The source of uncertainty include the uncertainty components such as measurement reproducibility, the benchmark zinc, the volume, and the average molar mass of mixed RE chloride and so on. According to the uncertainty method, every uncertainty component was calculated and was synthesized and extended in order to obtain the evaluation of uncertainty from measurement results. The result suggested that the total rare earth content in mixed chloride could be expressed as follows： （306.02± 1.73 ） g/L.