EDTA滴定法测定矿石中铅量的不确定度评定

Evaluation of Uncertainty in the Determination of Lead Content in Ore by EDTA Titration

采用EDTA滴定法测定矿石中铅的含量,通过建立不确定度评定数学模型,对实验过程和结果中涉及的不确定分量、合成不确定度和扩展不确定度进行计算和评定分析。结果显示,EDTA滴定法测定矿石中铅含量的合成不确定度为0.006586,扩展不确定度为0.01317,矿石中铅含量不确定度主要来源于消耗EDTA标准溶液的体积和试样中铅含量测定重复性,在实际的测定中应特别重视这两个因素。

Lead content in ore by EDTA titration,and a mathematical model of uncertainty evaluation was established.Then,each uncertain components involved in the experimental process and results was calculated and synthesized to evaluate the uncertainty in the determination of lead content in ore.Results showed that the synthetic uncertainty is 0.006586 and expanded uncertainty is 0.01317.The consumption of EDTA standard solution and repeatability of determination of lead content were the main source of uncertainty,and the special attention should be paid to these two factors in the practical work.