EDTA滴定法测定铟锡氧化物废靶粉中铟的含量

摘要

The mothod for determination of indium in ITO waste target powder by EDTA titration was established. The ITO waste target powder sample was dissolved in hydrochloric acid and nitric acid, tin in ITO waste target powder was removed by hydrobromic acid. The content of indium was determined by using EDTA direct titration method in the tempreture of 70-80℃ and pH 2.5-3.0,with glacial acetic acid as masking agent. The method improved conditions of removing tin, the acidity and temperature were optimized, and the choice and amount of the masking agent in the process of EDTA volumetric method was discussed. The recovery rate of indium was 99.4%-100.5% and the relative standard deviation was less than 1%(n=6). The method can meet the analysis requirement of the constant indium in ITO waste target powder.%建立用EDTA滴定法测定铟锡氧化物(ITO)废靶粉中铟含量的方法.ITO废靶粉样品经盐酸和硝酸分解,用氢溴酸加热除锡,以冰乙酸做掩蔽剂,pH控制在2.5~3.0之间,在70~80℃下用EDTA直接滴定法测定铟的含量.该方法改进了除锡条件,优化了酸度、温度,讨论了络合掩蔽剂及其用量的选择过程.在最佳实验条件下,铟的回收率为99.4%~100.5%,测定结果的相对标准偏差小于1%(n=6).该方法可以满足ITO靶材中常量铟的分析要求.