铑电镀液中铑含量不同测定方法的比较

铑作为一种贵金属,准确测定其在镀液中的含量非常重要.通过对铑的标准浓度溶液进行重量法、等离子体发射光谱法(ICP)、火焰原子吸收光谱法(FAAS)和改进后的FAAS(引入一个校正因子, 对FAAS测定方法进行了优化、校正)等不同方法的测定,比较了不同测定方法的适用范围和精确度.结果表明:对于杂质少的铑电镀液,宜采用重量法测定,其测定偏差在4%以内,硼氢化钠作为还原剂的重量法的测定偏差可控制在0.2%以内;对于杂质多的铑电镀液,用ICP,改进后的FAAS均能获得满意结果,相对偏差都小于1% .

Comparison of the Methods to Determine Rhodium Content in Plating Solution

With a view to the importance to accurately determine the concentration of noble metal rhodium in plating solution, the applicability and precision of various methods including gravimetric method, inductively coupled plasma spectrometry (ICP), flame atomic absorption spectrometry (FAAS), and improved FAAS (IFAAS, where a calibration factor was used to optimize and calibrate the test method) for the measurement of rhodium were investigated and compared using a rhodium standard solution as the test object. As the results, it was suggested to measure the rhodium in the electroplating solution containing few impurities using the gravimetric method, which gave a deviation below 4%. Specifically, the deviation for the measurement of the rhodium using the gravimetric method was decreased to be less than 0.2% while sodium borohydride was used as the reducing agent. Moreover, the rhodium in the electroplating solution containing many impurities could be readily measured using ICP and IFAAS with good choice, and the relative deviation in this case was less than 1%.