光亮硫酸盐镀锌液中硼酸测定方法的探讨

Study of the determination of boric acid in bright sulfate zinc electroplating baths

将氯化物镀锌液中硼酸的测定方法用于测量光亮硫酸盐镀锌液中硼酸的含量。从理论上分析了该方法所得结果偏低的原因。提出了普通滴定法和电位滴定法测量镀液中的硼酸。探讨了影响测量结果的各因素。结果表明 :普通滴定法回收率达 89.7% ,适用于常规分析 ,而电位滴定法回收率达 99 8% ,适用于精确测量。

Concentration of boric acid in bright sulfate zinc plating bath was determined referring to the same method for chloride type zinc plating bath. Theoretic reasons which resulted in lower measured value were investigated. Two methods such as general titration and potentiometric titration were advanced to determine the boric acid in bright sulfate zinc plating baths. Factors affecting the observed value were studied, with results indicate that the general titration has recovery of 89.7% which is suitable for routine analysis and potentiometric titration of 99.8% which suitable for accurate analysis.