中文摘要：

采用循环伏安（CV）法制备了聚对苯二酚薄膜修饰玻碳电极，利用其电催化氧化作用建立了抗坏血酸的定量分析方法，探讨了其催化氧化机理。研究发现：在0．2mol／L Na2HPO4-NaH2PO4（PBS，pH7．0）缓冲溶液中，以0．1mol／L KCl作支持电解质，聚对苯二酚修饰电极（PHQ／CME）对抗坏血酸（AA）存在灵敏的催化氧化作用，氧化峰电位负移177mV。应用微分脉冲伏安法（DPV）对AA进行定量分析，其氧化峰电流与AA浓度在3．3×10^-1～1．7×10^-2mol／L和1．7×10^-2～1．2×10^-1mol／L范围内呈良好的线性关系，检出限为3．3×10^-6mol／L。机理研究结果表明：PHQ／CME上带有的酚羟基与脱氢抗坏血酸自由基之间形成的氢键是电催化氧化的主要原因。

英文摘要：

The preparation of polyhydroquinone film modified glassy carbon electrode （PHQ/CME） and its electrocatalytic oxidation to ascorbic acid （AA） are presented. Several parameters,such as reaction time and pH, possible interference were examined. The peak currents were proportional to the concentration of AA in the range of 3.3 ×10^-5 - 1.7 ×10^-2 moL/L and 1.7 ×10^-2 - 1.2 ×10^-1 mol/L with a detection limit of 3.3 ×10^-6 moL/L The stability and repeatability of the electrode for the determination of ascorbic acid were also investigated. The method has been applied to the determination of AA in tablet. And the research of reaction mechanism showed that the hydrogen bond between AA and poly（hydroquinone） on the glassy carbon elecrode （GCE） was considered to be the main reason of the electrocatalytic oxidation.