测定氯化钾镀锌溶液中硼酸的新方法  

Novel method for determination of boric acid in potassium chloride zinc electroplating bath

作　　者：陈建锐[1] 郭崇武[1] CHEN Jian-rui GUO Chong-wu

机构地区：[1]广州超邦化工有限公司,广东广州510460

出　　处：《电镀与涂饰》2016年第19期1029-1030,共2页Electroplating & Finishing

摘　　要：制定了测定氯化钾镀锌溶液中硼酸的新方法。用草酸钾掩蔽锌离子及铁杂质，用氟化钠掩蔽铝杂质，用D-甘露醇与硼酸反应生成酸性较强的配合酸，以酚酞作指示剂，用氢氧化钠标准滴定溶液滴定配合酸。本法的相对标准偏差为0．25％，回收率为99．33％-100．00％，精密度和回收率都较高，解决了铝杂质对测定硼酸的干扰问题。A novel method of determining boric acid in potassium chloride zinc plating bath was established. Zinc ions and iron impurities are masked by potassium oxalate, and aluminum impurities are masked by NaF. Boric acid reacts with D-mannitol to produce a complex acid whose acidity is stronger than boric acid, and then the complex acid is titrated by standard NaOH solution with phenolphthalein as indicator. The method has high precision （relative standard deviation 0.25%） and high recovery （99.33%-100.00%）, and eliminates the interference of aluminum impurities on the determination of boric acid.

关 键 词：氯化钾镀锌溶液 硼酸 滴定分析 铝离子 掩蔽剂 

分 类 号：TQ153.15[化学工程—电化学工业] O655.25[理学—分析化学]