镍铁合金镀液中镍含量的快速光度法分析

摘要

制定了快速分析镍铁合金镀液中镍含量的方法.在碱性条件下,三异丙醇胺与镍离子生成稳定的黄绿色配合物,用于光度法测定镍的含量.镀液中的亚铁离子与抗坏血酸生成接近无色的配合物,且抗坏血酸不参与三异丙醇胺与镍离子的显色反应,因此不干扰镍的测定.镀液中的葡萄糖酸钠对镍的测定略有影响,但就镀液日常维护而言可以忽略不计.在测定条件下,锌和铝杂质与三异丙醇胺生成无色配合物,对测定镍无影响.以水作参比液,在波长420 nm处测定试液的吸光度,测定结果的相对平均偏差为0.63％,回收率为98.2％ ～ 100.2％.%A method for rapid analysis of nickel content in a Ni-Fe alloy electroplating bath was established.Triisopropanolamine reacts with nickel ion in alkaline condition,forming a stable yellowish green complex which is used to determine the nickel content by spectrophotometry.Ferrous ions in the electroplating bath react with ascorbic acid,forming almost colorless complexes,and ascorbic acid does not take part in the chromogenic reaction of triisopropanolamine with nickel ions,having no interference to the spectrophotometric determination of nickel.The effect of sodium gluconate in the electroplating bath on the nickel determination does exist,but is negligible for routine bath maintenance.Zn and A1 impurities are coordinated by triisopropanolamine,forming colorless complexes under the conditions of determination,having no effect on the nickel determination.The absorbance of test solution is determined at a wavelength of 420 nm with water as a reference.The method has a relative average deviation of 0.63％ and a recovery ranging from 98.2％ to 100.2％.