农药乐果的电化学性质及快速测定

Study on electrochemical characteristics and rapid determination of dimethoate

利用电化学沉积法制备了纳米金修饰的金电极,通过循环伏安法研究了乐果在该电极上的电化学性质,实现了乐果的快速测定。实验结果表明,乐果在碱性环境中可以水解生成巯基化合物,吸附到电极表面从而获得电化学信号。纳米金能有效地促进电子传递,同时其大的比表面积能够增加对水解液中巯基化合物的吸附量,提高检测的灵敏度。利用循环伏安法在最优条件下对乐果进行了检测,检测范围为1.6×10-6～2.6×10-4mol/L,检测限为8.5×10-7mol/L。

In this study,nano-gold modified gold electrode was obtained by electrochemical deposition method.The electrochemical characteristics of dimethoate on this modified electrode were investigated by cyclic voltammetry.The results indicated that dimethoate could be hydrolyzed to sulfhydryl compounds.The electrochemical response was obtained by the adsorbed sulfhydryl compounds on the electrode surface.The deposited nano-gold on the electrode could accelerate the electron transfer and could increase the amount of the adsorbed sulfhydryl compounds.Thus,the sensitivity for determination of dimethoate was improved.Under the optimal conditions,the linear range for determining dimethoate was 1.6×10^-6～2.6×10^-4 mol/L,with a detection limit of 8.5×10^-7 mol/L.