地表水中痕量铅和镉的同位镀锑膜修饰电极差分脉冲溶出伏安同时测定法

Simultaneous determination of trace lead and cadmium in surface water by differential pulse stripping voltammetry with in-situ plating antimony film-plated electrode

目的建立地表水中痕量铅、镉的同位镀锑膜修饰电极差分脉冲溶出伏安同时测定法。方法溶液中sb3＋浓度为1．0mg／L，富集时间为180S，富集电位为-1．2V，采用同位镀锑膜修饰玻碳电极差分脉冲溶出伏安法测定地表水中的铅、镉含量。结果在优化的实验条件下，铅、镉分别在-0．48V、-0．74V电位下出现良好的溶出峰；在10～100μg/L的线性范围内，铅、镉的溶出峰电流（1p）与铅、镉浓度（c）呈较好的线性关系（r值分别为0．9905，0．9990），检出限分别为0．99和1．2lμg／L，回收率为92．1％～107．6％，RSD为3．1％～8．6％。结论该方法简单快速、灵敏度高、检出限低，不需要贵重仪器，适用于地表水中痕量铅、镉的同时测定。

Objective To establish the simultaneous determination method of lead and cadmium by differential pulse stripping vohammetry with in-situ plating antimony film-plated electrode. Methods Following 180 s preconcentration, -1.2 V preconcentration potential and 1.0 mg/L Sb3＋, antimony film-plated glassy carbon electrode was used as the working electrode for the determination of trace lead and cadmium by differential pulse stripping voltammetry. Results Under optimized conditions,well defined peaks of lead and cadmium were obtained at the potential of -0.48 V and -0.74 V respectively. The stripping peak currents changed linearly with the concentration of lead and cadmium over the range from 10 to 100 μg/L （r≥ 0.990 5）. The detection limits of lead and cadmium were 0.99 μg/L and 1.21 μg/L respectively, and the recoverT rates were 92.1%-107.6%, the RSDs were 3.1%-8.6%. Conclusion The antimony film-plated electrode is applicable to the simultaneous determination of lead and cadmium in surface water with good convenience, sensitivity and reliability.