对硫磷在聚乙烯吡咯烷酮修饰碳糊电极上的电化学行为及其分析研究

Studies on electrochemical behaviors and analysis of parathion at a polyvinylpyrrolidone modified carbon paste electrode

研究了对硫磷在聚乙烯吡咯烷酮(PVP)修饰碳糊电极(CPE)上的电化学行为,发现PVP能显著提高对硫磷的氧化还原峰电流。据此建立了一种直接测定对硫磷的电分析方法。对硫磷氧化峰电流与其浓度在2.5×10^(-8)～1.0×10^(-6) mol/L及1.0×10^(-6)～1.0×10^(-5) mol/L范围内呈良好的线性关系,开路富集5 min后,检出限为7.5×10^(-9) mol/L。在1.0×10^(-5)mol/L的对硫磷试液中连续测定10次,其RSD为2.8%。用此方法测定了蔬菜中的对硫磷。

The electrochemical behaviors of parathion （PT） at the polyvinylpyrrolidone （PVP） modified carbon paste electrode（CPE） were investigated. It is found that PVP significantly enhances the redox peak currents of FF. All the experimental parameters were optimized and a simple and sensitive electroanalytical method was developed for the determination of PT. The oxidation peak current is linear with the concentration of PT over the range from 2.5 × 10^-8 mol/L to 1.0× 10^-6 mol/L and 1.0× 10^-6 mol/L to 1.0× 10^-5 mol/L. A low detection limit of 1.0× 10^-8 mol/L was obtained for 5 min accmnulation at open circuit （S/N = 3）. The relative standard deviation （ n = 10） was 2.8% for 1 × 10^-5 mol/L PT. The proposed method was used for quantitative analysis of PT in some vegetables and the results were satisfying.