A method for analysis of zinc impurity in cyanide copper plating bath by using triethanolamine as masking agent instead of potassium cyanide was introduced. Cu+ ions react with triethanolamine forming stable complexes, and cannot be oxidized to Cu2+ ions in presence of L-ascorbic acid. Free cyanide is destroyed by formaldehyde, and zinc is then titrated with EDTA at pH 10 using eriochrome black T as indicator. The tests showed that the relative average deviation of the method is 1.4%.%介绍了用三乙醇胺作掩蔽剂取代氰化钾来测定氰化镀铜溶液中锌杂质的方法.三乙醇胺与Cu+离子生成稳定的配合物,在左旋抗坏血酸存在的条件下,Cu+离子不能被氧化成Cu2+离子.测定时加甲醛破坏游离氰化钠,以铬黑T作指示剂,在pH=10的条件下用EDTA滴定锌.实验表明,测定结果的相对平均偏差为1.4％.
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