基于石墨烯修饰电极测定蔬菜中残余对硫磷的研究

Determination of Residual Parathion Based on the Graphene Modified Glassy Carbon Electrode

制备了石墨烯薄膜修饰玻碳电极,并通过循环伏安法研究了对硫磷（PT）在该修饰电极上的电化学行为。对支持电解质、溶液pH值等实验条件进行了优化。结果表明,在0.1mol/L的乙酸-乙酸钠缓冲溶液（pH=5.0）中,PT在石墨烯薄膜修饰电极上具有良好的电化学响应,对比裸玻碳电极,PT的氧化峰峰电流显著提高,表明修饰膜对PT的电化学氧化具有一定的催化作用。PT的氧化峰电流及其浓度分别在1.0×10^-7-1.0×10^-6 mol/L范围内和3.0×10^-6-1.0×10^-5 mol/L范围内呈良好的线性关系,线性相关系数分别是0.9956和0.9874,检出限为1.0×10^-8 mol/L。将该修饰电极应用于小白菜中残留PT的测量,结果比较满意。

The electrochemical behavior of parathion（PT） on a graphene film modified glassy carbon electrode was studied by cyclic voltammetry. The results indicated that PT had a good electrochemical response in 0.1 mol/L of acetic acid-sodium acetate buffer（pH 5.0） on graphene film modified electrode. Compared with the bare electrode, the redox peak current of parathion significantly improved, which showed that the graphene film had catalytic ability for the electrochemical redox of parathion. The oxidation peak current of parathion was linear with its concentration in the range of 1.0×10^-7-1.0×10^-6 mol/L and in the range of 3.0×10^-6-1.0×10^-5 mol/L with their linear correlation coefficients of 0. 9847 and 0. 9996, respectively. The detection limit was 1.0×10^-8 mol/L （S/N = 3）. The modified electrode was used to detect the content of residual parathion in vegetables.