Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute, Karaikudi, 630006, Tamil Nadu, India.
Analyst. 2013 Oct 7;138(19):5674-8. doi: 10.1039/c3an01070h.
In this work, the determination of cadmium has been attempted using an indium film electrode in the presence of bromide ions as an additive, for the first time. The electrode was prepared in situ on a glassy carbon substrate and employed in combination with square wave anodic stripping voltammetry. The purpose of having bromide ions is to enhance the analytical value of cadmium detection. In the absence of bromide ions, cadmium stripping peaks coalesce with indium and it is difficult to resolve for analytical purposes. The addition of bromide ions strongly influences the peak separation, thanks to the complex-forming characteristics of cadmium with bromide ions. Several key operational parameters influencing the electroanalytical response of indium modified electrodes were examined and optimized, such as deposition potential, pH, bromide ion and indium concentration. The indium modified electrode exhibited well-defined, separated stripping signals and revealed good linear behavior in the examined concentration range from 1 to 25 ng ml(-1). The present method shows a low detection limit value of 0.36 ng ml(-1). These results suggest that the proposed electrode contributes to the wider applicability of electrochemical stripping techniques in connection with "mercury-free" electrodes.
本工作首次尝试在溴离子存在的情况下使用铟膜电极来测定镉。该电极是在玻碳基底上原位制备的，并与方波阳极溶出伏安法结合使用。引入溴离子的目的是增强镉检测的分析价值。在没有溴离子的情况下，镉的溶出峰与铟峰融合，难以进行分析。由于镉与溴离子形成络合物的特性，溴离子的加入强烈影响峰的分离。考察并优化了影响铟修饰电极电分析响应的几个关键操作参数，如沉积电位、pH 值、溴离子和铟浓度。铟修饰电极呈现出良好定义的、分离的溶出信号，并在 1 至 25ngml(-1)的检测范围内表现出良好的线性行为。本方法的检测限低至 0.36ngml(-1)。这些结果表明，所提出的电极有助于电化学溶出技术在与“无汞”电极相关的更广泛应用。
