采用阳极溶出伏安法,在厚膜印刷的碳浆电极上同步镀铋测定痕量重金属元素铅和镉。文中研究了碳浆电极的预处理、溶液中铋离子浓度、预富集时间等因素对测量的影响。实验结果表明铅、镉在铋膜修饰的碳浆电极上可得到灵敏的阳极溶出峰,峰高和溶出电位与汞膜电极法相近。使用铋膜电极可避免使用汞电极带来的环境污染,同时采用厚膜印刷的碳浆电极可以大大降低检测成本,实现电极的单次使用。
This paper reported the detection of trace heavy metal ions, lead and cadmium, with in-situ bismuth-coated thick-film carbon electrodes by anodic stripping voltammetry. The influence of carbon electrodes pretreatment, bismuth ion concentrations, preconcentration time upon the stripping responses were investigated. Experimental results indicate that anodic stripping voltametric measurements of lead and cadmium on bismuth-coated carbon electrodes yield well-defined peaks, whose peak potential and height are in a manner analogous to those of in-situ plated mercury-film electrodes. Using bismuth instead of mercury avoids the pollution. Due to the low cost of thick-film process, the thick-film carbon electrode could be used as disposable device.