Zn-Ni合金镀液中Ni^(2+)含量的直接分光光度法测定

Determination of Ni^(2+) in Zinc-Nickel Electroplating Solution by Direct Spectrophotometric Method

为了简便、快速而准确地测定Zn-Ni合金镀液中的Ni2+含量,不使用任何化学显示剂,利用分光光度法研究了Ni2+,Ni2+/Na+,Ni2+/Zn2+体系中Ni2+的吸光特性。结果表明:在Ni2+体系中,Ni盐浓度为5～100g/L,入射光波长为660 nm时,Ni2+浓度与吸光度呈线性关系;在Ni2+/Na+,Ni2+/Zn2+体系中,Na+和Zn2+对该波长入射光无吸收,由此提出了Zn-Ni合金镀液中Ni2+含量的快速测定方法;对Ni2+,Na+,Zn2+共存的标准溶液中Ni2+含量测定结果显示,本方法操作简单、速度快、准确度高。

The optic absorption behavior of Ni2+ in Ni2+/Na+,Ni2+/Zn2+ and single Ni2+ systems was investigated by spectrophotometry without any chemical indicator,with a hope to realize the facile,fast and accurate determination of Ni2+ in Zn-Ni alloy electroplating solution.It was found that,in single Ni2+ system with a nickel salt concentration of 5~100 g/L,the concentration of Ni2+ was linearly proportional to the absorbance under incident light with a wavelength of 660 nm.However,in Ni2+/Na+ and Ni2+/Zn2+ systems,Na+ and Zn2+ showed no absorbance under irradiation of the same incident light.Thus a direct spectrophotometric method was established to fast detect the concentration of Ni2+ in Zn-Ni alloy electroplating solution.Measurement of the concentration of Ni2+ in the standard solution containing Ni2+,Na+ and Zn2+ indicated that the established spectrophotometric method could be readily used to detect Ni2+ with a good accuracy.