电化学传感分析平台测定污水中的Cr(Ⅵ)

Determination of Cr(Ⅵ)in Wastewater by Electrochemical Sensor Analysis Platform

结合微型电化学仪器,研究了一种快速、便携、灵敏的Cr(Ⅵ)电化学传感分析平台,用于污水中Cr(Ⅵ)的检测。采用三电极体系,差分脉冲阴极溶出伏安法(DPCSV),记录伏安曲线中Cr(Ⅵ)的还原峰。Cr(Ⅵ)的溶出峰电流与其浓度在2~500μmol/L范围内有良好的线性关系,测得Cr(Ⅵ)的检出限为0.55μmol/L(28.60μg/L),达到了世界卫生组织(WHO)规定的饮用水中Cr(Ⅵ)的最高含量50μg/L。测得镀铬厂废水中Cr(Ⅵ)含量为2.03μmol/L,与国家标准方法中光谱学分析法的测定结果基本一致。方法重现性好、灵敏度高,使其应用在现场实时监测环境中的Cr(Ⅵ)含量具有很大的潜力。

A rapid,portable and sensitive electrochemical sensing platform has been successfully constructed for chromium(Ⅵ)determination in wastewater,combining with micro electrochemical system(μECS).The reduction peak of Cr(Ⅵ)was recorded by differential pulse cathodic stripping voltammetry(DPCSV)with three electrodes.We obtained a good linear responses of the peak current against the concentrations of Cr(Ⅵ)over the range of 2—500μmol/L and the detection limit was 0.55μmol/L(28.60μg/L).The detection limit of Cr(Ⅵ)reached the guideline value set by world health organization(WHO)for Cr(Ⅵ)in groundwater(50μg/L).The concentration of Cr(Ⅵ)in the chrome-plating industry sewage water was 2.03μmol/L,which was consistent with the data using the spectroscopic analysis in national standard method.This method has good reproducibility and high sensitivity,so it has great potential in the field real-time monitoring of Cr(Ⅵ)in the environment.