多壁碳纳米管修饰玻碳电极伏安法测定香草醛

Voltammetric Determination of Vanillin on a Multi-walled Carbon Nanotubes Modified Glassy Carbon Electrode

制备了羧基化多壁碳纳米管修饰玻碳电极(c-MWCNTs/GCE),采用循环伏安法在0.5 mol/L HCl中研究了食品添加剂香草醛的电化学行为。结果显示,该修饰电极对香草醛的电化学氧化具有良好的电催化作用,与裸玻碳电极相比电流响应显著增强。香草醛在该修饰电极上的氧化为不可逆的扩散控制过程。在最佳条件下,采用二阶导数线性扫描伏安法进行测定,香草醛的氧化峰电流与其浓度在0.1～6.0μmol/L和6.0～100μmol/L范围内呈良好的线性关系,检出限(S/N=3)为0.02μmol/L。该修饰电极具有良好的重现性(RSD=4.6%)和稳定性。方法应用于食品中香草醛的测定,回收率为96.3%～104%。

A carboxylated multi-walled carbon nanotubes modified glassy carbon electrode(c-MWCNTs/GCE) was fabricated,and the electrochemical behavior of vanillin was studied in 0.5 mol/L HCl using cyclic voltammetry.Results revealed that the modified electrode showed an better electrocatalytic activity toward the oxidation of vanillin by a significant enhancement in the current response compared with that of the bare glassy carbon electrode.The oxidation of vanillin at this electrode was irreversible and diffusion-controlled.Under the optimum conditions,by second-order derivative linear scan voltammetry,the anodic peak current showed a linear relation versus vanillin concentration in the ranges of 0.1-6.0 μmol/L and 6.0-100 μmol/L with a detection limit(S/N=3)of 0.02 μmol/L.Moreover,the modified electrode demonstrated a good reproducibility(RSD=4.6%) and a long-term stability.This method was applied in the determination of vanillin in food samples with recoveries of 96.3%-104%.