基于炭气凝胶修饰BDD电极对甲基对硫磷的检测

Determination of methyl parathion based on carbon aerogels modified BDD electrode

利用炭气凝胶(CAs)修饰硼掺杂金刚石(BDD)电极对甲基对硫磷进行检测。1.0×10-4mol/L甲基对硫磷在裸BDD电极和CAs-BDD电极上的差分脉冲伏安结果表明,经CAs修饰后,峰电流从4.576μA增加到10.43μA,峰电位从-0.644 V移至-0.556 V,说明CAs具有较高的电催化活性,可促进电极表面的电子转移,加快反应速率。研究了不同pH的缓冲液和修饰量对电极响应的影响,实验得出最佳缓冲液pH=6.8,最佳修饰量为5μL。在最优条件下,甲基对硫磷的浓度与其峰电流在4～200μmol/L范围内呈线性关系,线性方程为I p=-0.03222 c-2.09172(r2=0.9979),检出限为1.188μmol/L。采用本方法对实际样品中的甲基对硫磷的含量进行测定,平均回收率为98.4%～106.6%之间。

A carbon aerogels（CAs） modified boron-doped diamond（BDD） electrode has been successfully developed for the detection of methyl parathion.Differential pulse voltammetry was utilized to investigate the properties of the bare BDD electrode and the CAs-BDD electrode in a 1.0 × 10-4mol / L methyl parathion solution.The results indicated that CAs had highly electrocatalytic activity and improved the electron transfer.The effect of pH of different buffer solutions and modified quantity on the electrode response was studied,and the results showed that the optimal buffer solution pH was 6.8 and the optimal modified quantity was 5μL.Under the optimized conditions,the peak current was proportional to methyl parathion concentration ranging from 4 to 200 μmol /L,and the linear equation was I p =-0.03222 c-2.09172（r2= 0.9979）,with a detection limit of 1.188 μmol /L.The recoveries for practical samples obtained from the modified BDD electrode were calculated to be 98.4% ～ 106.6%.