阳极溶出伏安法测自来水中痕量砷离子的研究

摘要

为采用阳极溶出伏安法(ASV)测定不同形态的砷(As),优化了pH值、沉积电位、沉积时间和支持电解质等影响因素.结果表明:该体系在1~100 μg/L峰电流与As(Ⅲ)的浓度呈现良好的线性关系,相关系数为0.998,检出限为37.5 ng/L,8次重复测定10 μg/L As(Ⅲ)RSD为1.27%.该方法可通过还原As(V)为更有电活性的As(Ⅲ)来实现As(V)的测定,可用于检测自来水样品中超痕量As(Ⅲ)和As(V),测定结果与电感耦合等离子质谱结果相一致,实现了不同形态砷的测定.%To determine different forms of arsenic by anodic stripping voltammetry (ASV), factors including pH, deposition potential, deposition time, and supporting electrolyte were optimized.The results showed that the optimized system provided a linear calibration in the range of 1 to 100 μg/L, with a respective correlation coefficient of 0.998, and a detection limit of 37.5 ng/L.The RSD was 1.27% for 10 μg /L of As(Ⅲ) with eight repetitive measurements.The method could be used to determine As (V) by chemical reduction of As (V) to more electroactive As (Ⅲ) and to detect ultra-trace As (Ⅲ) and As (V) in tap water.The results agreed well with that of ICP-MS and was also capable of determining different forms of arsenic.