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目的建立了水样中甲基对硫磷的线性扫描伏安测定法。方法采用三电极系统,以电化学活化玻碳电极为工作电极,Ag-AgCl电极为参比电极,铂电极为对电极,在HAc-NaAc缓冲溶液(pH=5.0)中,采用循环伏安法在-0.8～0.5 V扫描电位、0.1 V/s扫描速度下,研究14.4μmol/L的甲基对硫磷的电化学行为。结果活化玻碳电极对甲基对硫磷具有明显的电催化作用,电极反应过程是吸附控制过程。催化氧化峰电流与甲基对硫磷浓度在0.72～14.4μmol/L范围内呈良好的线性关系,线性方程为ipa=0.105 3+0.246 0c,r=0.999 2,该方法的检出限为0.425μmol/L,平均回收率为98.0%～101.9%,RSD为2.7%。结论该方法简便、快捷、灵敏度高,适用于实际水样中甲基对硫磷的测定。
Objective To establish a linear sweep voltammetric assay for methyl parathion in water samples. Methods Electrochemical activated glassy carbon electrode was used as working electrode, Ag-AgCl electrode was used as reference electrode and platinum electrode was used as counter electrode in HAc-NaAc buffer solution (pH = 5.0) by cyclic voltammetry Electrochemical behavior of 14.4 μmol / L methyl parathion was investigated at -0.8 ~ 0.5 V scan potential and 0.1 V / s scan rate. Results Activated glassy carbon electrode has obvious electrocatalysis on methyl parathion, and the electrode reaction process is controlled by adsorption. The linear relationship between the peak current of catalytic oxidation and the concentration of methyl parathion in the range of 0.72 ~ 14.4μmol / L showed a good linear relationship. The linear equation was ipa = 0.105 3 + 0.246 0c, r = 0.999 2. The detection limit was 0.425 μmol / L, the average recovery was 98.0% ~ 101.9%, RSD was 2.7%. Conclusion The method is simple, rapid, sensitive and suitable for the determination of methyl parathion in water samples.