离子液体修饰碳糊电极测定食品中香草醛

Analysis for Vanillin in Food at Imidazole Type Carbon Ionic Liquids Modified Electrode

摘要:

本文合成1-丁基-3-甲基咪唑四氟硼酸[BMIM]BF4，用该离子液体构置了具更高导电效率的修饰电极。在pH=7.4的磷酸二氢钠-磷酸氢二钠缓冲溶液中，用循环伏安法和差分脉冲伏安法研究了香草醛在离子液体修饰电极和碳糊电极上的电化学行为，建立了测定香草醛的电化学方法，离子修饰电极显示了更好的电化学特性，在+0.440 V (vs.SCE)左右有一个不可逆的氧化峰。DPV法线性范围2.0 μg/mL~30.0 μg/mL，检测限1.0 μg/mL。并对香草醛的电极反应机理做了初步研究。

Abstract:

A new kind of carbon paste electrode modified with ionic liquid BMIM BF4 was fabricated. In phosphate buffer solution (pH 7.4), cyclic voltammetry and differential pulsc voltammetry were used to investigate the electrochemical behavior of vanillin at the modified dectrode and a new method for selective detection of vanillin was established. The results showed that the electrochemical response was greatly improved with the high conductivity of ILs compared with that of traditional CPE. The vanillin showed a sensitive oxidative peak at 0.440V (VS.SCE), and the peak current was linear to the concentration of vanillin ranging from 2.0 μg/mL-30.0 μg/mL with a detection limit of 1.0 μg/mL. The determination of vanillin hydrochloride was performed and the mechanism for the electrode process was also proposed.