流通电解池-连续介质交换差示脉冲阳极溶出伏安法同时测定镉、铟

Simultaneous Determination of Cadmium and Indium by Differential Pulse Anodic Stripping Voltammetry With a Flow-through Cell and Medium Exchange

本文采用自制流通电解池,在盐酸溶液中富集Cd(Ⅱ),In(Ⅲ),经连续介质交换,在选定的乙二胺-氯化钠溶液中进行差示脉冲阳极溶出。得到的镉、铟溶出峰△Ep≥100mV。波形完好。从根本上解决了盐酸溶液中Cd(Ⅱ)、In(Ⅲ)的阳极溶出峰相重叠的问题。建立了一个灵敏、快速,同时测定镉、铟的分析方法。

Differential pulse anodic stripping voltammetry with a flow-through cell and medium exchange method to increase resolution of cadmium and indium ion in HCI solution was described. A flow-through cell with a hanging mercury drop electrode was designed. The Ag/AgCl reference electrode and Pt auxiliary electrode were fixed in a downsteam compartment. The medium exchange procedure involves a deposition of cadmium and indium ion from HCI solution, followed by stripping them into a selected NH_2CH_2CH_2-NH_2-NaCl media. Both peaks of cadmium and indium were separated well with △Ep>100 mV. Therefore, the problem of overlapping peaks of cadmium and indium in anodic stripping voltammetry was resolved. The relative standard deviation and linear range for Cd(Ⅱ) and In(Ⅲ) are 0.341％, 0.304％ and 1.8×10^(-8)～8.0×10^(-6), 1.7×10^(-8)～8.7×10^(-6)mol/L, respectively. In order to explore the electrochemical behaviors of cadmium and indium in NH_2CH_2CH_2NH_2-NaCl media, cyclic voltammetry of the two ions was studied.