方波伏安法快速测定镀镍液中的镍含量

Rapid determination of nickel content in nickel plating baths by square wave vlotammetry

由于利用传统方法测定镀镍液中的镍含量时共存离子的干扰不易消除 ,在此采用方波伏安法进行测定。阐述了该方法的原理 ,探讨了试验条件、共存离子对测量结果的影响。结果发现 ,在pH =10 .0的NH3·H2 O -NH4 Cl缓冲液中以三乙醇胺为掩蔽剂 ,镍 (Ⅱ )于 -1.12V(vsSCE)出现极谱峰 ,在镍 (Ⅱ )浓度为 2～ 2 0g/L范围内峰电流与镍 (Ⅱ )浓度成线性关 ,镍 (Ⅱ )检出限为 0 5mg/L。该方法简单、快速、准确度和灵敏度高 ,适用于微量镍的测定。

On account of the disturbance of coexistent ions during the traditional determination of nickel content in nickel plating baths, square wave voltammetry was adopted. The fundamental of the method was introduced. Effects of test conditions and coexistentions on the tested results were studied. In buffer solution of ammonia water-ammonium chloride with pH value was 10 and triethanolamine acted as masking agent, the electrochemical spectrum curve of nickel(Ⅱ) reached a peak value at potential of -1.12 V(vs SCE), and the peak current was in direct proportion to nickel (Ⅱ) content provided that nickel(Ⅱ) content lies between 2 to 20 milligrams per liter, the low limit of nickel that could be measured is 0.5 milligrams per liter. This method is simple, rapid, accurate and sensitive which is suitable for microdetermination of nickel.