氰化光亮镀铜溶液中氢氧化钠的分析方法

Method for Analyzing Sodium Hydroxide in the Bright Cyanide Copper-plating Bath

氰化光亮镀铜溶液,由于添加剂和其分解产物的影响,以酚酞作指示剂用盐酸滴定氢氧化钠,测定结果明显偏高。为此,制定了以百里酚酞作指示剂测定氢氧化钠的分析方法,试验表明,镀液中的光亮剂及其分解产物不影响氢氧化钠的测定。本法相对平均偏差为0.96%,回收率为98.5%～100%。

When sodium hydroxide in cyanide copper-plating bath containing brightening agents was determined by hydrochloric acid titration with phenothalin as indicator, the determination error was very big, because the brightening agents and their decomposition products disturbed the determination. Therefore, the hydrochloric acid titration with thymophthalein as indicator for analyzing sodium hydroxide in the bright cyanide plating-copper bath was established. The cyanide was masked by using silver nitrate and the carbonate was deposited using barium chloride. The measurement results show that the determination isnt influenced by the brightening agents and their decomposition products. The relative average deviation for the method is 0.96% , the recovery ratio is 98.5% - 100%.