Determination of lead and cadmium by differential pulse voltammetry based on hexakis(cyanoC)iron potassium/Perfluorosulfonic acidPTFE copolymer composite film modified glassy carbon electrode
LIU Xue, WANG Lan, WU Zhiwei, LUO Dingfa, HUANG Kejing
Department of Chemistry, Xinyang Normal University, Xinyang 464000,China
Abstract：A modified electrode was prepared with glassy carbon electrode through modification first with Prussian blue by electropolymerization method and then with Perfluorosulfonic acidPTFE copolymer(Nafion) film. The electrochemical behavior of Pb2+ and Cd2+ on the prepared electrode was studied by differential pulse voltammetry (DPV). A new determination method of Pb2+ and Cd2+ with high sensitivity was established. The experimental conditions such as accumulation potential, accumulation time and Nafion dosage were optimized. After stirring and accumulation at -1.1 V for 450 s in 0.1 mol/L NaAcHAc buffer solution at pH 4.5, the oxidation peak currents at -0.48 V and -0.73 V were measured with DPV, respectively. The stripping peak current showed good linearity to the concentration of Pb2+ and Cd2+ in the range of 5×10-85×10-5 mol/L and 2×10-82×10-5 mol/L, respectively. The correlation coefficients were 0.995 and 0.992, respectively. The detection limits were 5×10-9 mol/L for Pb2+ and 2×10-9 mol/L for Cd2+ (S/N=3). The proposed method was applied to the determination of Cd2+ and Pb2+ in water sample. The results were consistent with those obtained by atomic absorption spectrometry, and the relative standard deviation (RSD) was 2.1 %38 %.
刘雪，王兰，吴志伟，骆定法, 黄克靖. 六氰合铁酸铁/全氟磺酸聚四氟乙烯共聚物复合膜修饰玻碳电极差分脉冲伏安法测定铅和镉[J]. 冶金分析, 2012, 32(1): 38-42.
LIU Xue, WANG Lan, WU Zhiwei, LUO Dingfa, HUANG Kejing. Determination of lead and cadmium by differential pulse voltammetry based on hexakis(cyanoC)iron potassium/Perfluorosulfonic acidPTFE copolymer composite film modified glassy carbon electrode. , 2012, 32(1): 38-42.
