差分脉冲伏安法在线测定水中痕量砷

Differential Pulse Voltammetry for Trace Arsenic Detection On-line in Surface Water

本文主要介绍了一种准确、快捷、方便测定砷的新分析方法:在加入硫酸盐的酸性电解质溶液中,采用差分脉冲伏安法原理,在金膜电极上完成砷的富集和测定;研究沉积电位、沉积时间、增量电压、脉冲宽度及脉冲振幅等差分脉冲伏安法参数对测量的影响,通过引入四氯金酸,分析溶出过程中金离子与金膜电极的共振效应对测定信号的作用。结果表明,通过对差分脉冲参数及测量体系的优化,可实现ng/L级别的水质痕量砷元素的定量分析,可广泛用于地表水、地下水和海洋等水质砷的准确检测。

Differential pulse voltammetry(DPV),a novel,convenient and efficient analytical method for determination of trace arsenic levels is introduced in this study.Arsenic enriches on Au film electrode in acid electrolytic solutions with sulfate and then is detected using differential pulse voltammetry.Particularly,impacts of deposition time,depostion potentials,potential increments,pulse width,pulse period and amplitudes on accuracy of DPV are investigated.Besides,effects of resonance between Au3+and Au film electrode during stripping on detection signals are also studied with the addition of chloroauric acid.Results show that quantitative analysis of trace arsenic down to ng/L levels can be conducted by the optimisation of DPV parameters and measurement systems,making it feasible for arsenic determination in surface water and ground water.