EDTA滴定法测定铅锡合金中铅

建立了沉淀分离-EDTA滴定法测定铅锡合金中铅的分析方法。用硫酸溶样，在酒石酸存在下，铅生成硫酸铅与锡分离，然后硫酸铅转化成乙酸铅，在pH 5.5的乙酸-乙酸钠缓冲溶液中，以二甲酚橙为指示剂，用EDTA标准溶液滴定测出铅的含量。方法应用于实际样品测定，结果与认定值或原子吸收法相符，回收率介于98%~101%之间。精密度实验中，两个实际样品测定结果的相对标准偏差分别为0.13%（n=9）和0.14%（n=9）。方法操作简单、测定快速，适用于铅锡合金中铅的测定。

Determination of lead in lead-tin alloy by EDTA titration method

The analysis method of lead in lead-tin alloy by precipitation separation-EDTA titration was established. The sample was dissolved with sulfuric acid. In presence of tartaric acid, the lead was translated to lead sulfate and separated from tin. Then, the lead sulfate was converted to lead acetate. The content of lead was determined by EDTA titration in HAc-NaAc buffer solution at pH5.5 and using xylenol orange as indicator. The proposed method was applied to the determination of actual sample, and the results were consistent with the certified values or those obtained by other methods. The recoveries were between 98 % and 101 %. In precision test, the relative standard deviation (RSD, n=9) of two actual sample was 0.13 % and 0.14 %, respectively. This method was simple and fast, and it was applicable for the determination of lead in lead-tin alloy.