CPB自组装膜修饰碳糊电极对抗坏血酸的电催化氧化  

Electrocatalytic Oxidation of Ascorbic Acid at CPB-SAM in Situ Modified Carbon Paste Electrodes

作　　者：韩晓霞[1] 马娟[1] 高作宁[1] 

机构地区：[1]宁夏大学能源化工重点实验室,宁夏银川750021

出　　处：《宁夏大学学报（自然科学版）》2007年第2期147-150,共4页Journal of Ningxia University(Natural Science Edition)

基　　金：教育部科研重点基金资助项目(204149);宁夏高等学校科研基金资助项目(200623)

摘　　要：研究了抗坏血酸(AA)在溴化十六烷基吡啶(CPB)自组装膜现场修饰碳糊电极(CPB/CPE)上的电化学性质,测得了AA在CPB/CPE上的电化学动力学参数,电荷转移系数α,扩散系数D及速率常数kf,同时研究了介质pH值对AA氧化峰电流和氧化峰电位的影响.运用微分脉冲伏安法(DPV)研究了AA在CPB/CPE上的伏安行为,研究发现AA浓度在7.0×10-6～6.0×10-3mol/L的范围内氧化峰电流与其呈良好的线性关系,该修饰电极可直接应用于市售商品药及市售饮料中AA的测定,结果令人满意.The electrochemical behavior of the ascorbic acid was investigated at carbon paste electrcode （CPE） and surfactant modified carbon paste electrodes （CPB/CPE）. AA on the Unmodified and Modified electrodes showed an irreversible redox process . AA oxidation peak potential shifted more negatively and the peak current increased on the CPB/CPE, so CPB/CPE could catalyze the electrochemical oxidation of AA. The kinetic parameters such as charge transfer coefficient a, diffusion coefficient D and apparent reaction rate constant kf were determined by CV, CC and CA. Differential pulse voltammetry was employed for the determination of AA. A good linear relationship existed between the peak current and the concentration in the range of 7.0 × 10^-6 - 6.0× 10^-3 mol/L with the detection limit of 2.0 × 10^-6 mol/L. The proposed method has been applied to the determination of AA in tablets and the food.

关 键 词：抗坏血酸 溴化十六烷基吡啶 碳糊电极 自组装 电催化 

分 类 号：O657.1[理学—分析化学]