咖啡酸苯乙酯在玻碳电极上的电化学行为研究

采用循环伏安法和差分脉冲伏安法研究了咖啡酸苯乙酯(CAPE)在玻碳电极表面上的电化学行为。在0.05 mol.dm-3磷酸盐缓冲溶液(PBS,pH=7.6)中,CAPE在0.229 V和0.214 V处呈现一对明显的氧化还原峰。考察了溶液pH值和扫描速率等因素对CAPE电化学行为的影响,结果表明,电化学过程中CAPE的电子转移数为2,参与反应的质子数也为2,且为吸附控制过程。在0.05 mol.dm-3磷酸盐缓冲溶液(PBS,pH=7.6)中,CAPE的氧化峰电流与其浓度在0.34～3.40μmol.dm-3范围内成线性关系,其响应灵敏度为0.88μA/μmol.dm-3,检出限为60 nmol.dm-3(S/N=3)。本研究建立了一种简单、快速、可灵敏测定CAPE的方法。同时对CAPE在玻碳电极上的电化学行为进行了较为详细的研究。

Electrochemical behaviours of caffeic acid phenethyl ester on glassy carbon electrode

The electrochemical behaviours of caffeic acid phenethyl ester(CAPE)on glassy carbon electrode(GCE)were investigated by cyclic voltammetry and differential pulse voltammetry.In 0.05 mol·dm-3 PBS solution(pH=7.6),a pair of oxidation and reduction peaks were obtained at 0.229 V and 0.214 V(vs.Ag/AgCl)respectively.The effects of factors such as pH value and scanning rate on the electrochemical behaviours of CAPE were investigated.The results demonstrated that the number of electronic transfer was found to be 2 and the number of protons taken part in the reaction was also 2 in the electrochemical process of CAPE.Linear responses were obtained over a concentration range from 0.34 μmol·dm-3 to 3.4 μmol·dm-3 with sensitivity of 0.88 μA/μmol·dm-3 and a detection limit of 60 nmol·dm-3(S/N=3).A simple,rapid and reliable direct electrochemical analysis method for determination of CAPE was established.The response mechanism was discussed.