2-氨基吡啶修饰电极的电化学性质及对抗坏血酸的测定

Electrochemical Behavior of 2-Pyridinamine Modified Glassy Carbon Electrode and Its Application to the Determination of Ascorbic Acid

研究了２－氨基吡啶聚合膜修饰玻碳电极的制备及其电化学性质，并用于抗坏血酸（ＡＡ）的测定。在ｐＨ５．７ＢＲ缓冲溶液中，ＡＡ在 ２－氨基吡啶修饰电极上产生一灵敏的氧化峰，峰电流与ＡＡ浓度在４ × １０－６～１０－３ｍｏｌ／Ｌ范围内呈良好的线性关系，检测下限为 １．３ × １０－６ｍｏｌ／Ｌ。该电极对 ＡＡ有增敏作用，对多巴胺（ＤＡ）有排斥作用，重现性良好，可用于ＡＡ的测定。

The fabrication and electrochemical characteristics of 2-pyridinamine modified glassy carbon electrode were investigated. The electrode was applied to the determination of ascorbic acid. In BR buffer of pH 5.7, a sensitive oxidation peak was observed at 0.228 mV with 2-pyridiamine modified glassy carbon electrode. The current is proportional to the concentration of ascorbic acid in the range of 4 x 10(-6) similar to 10(-3) mol/L, the detection limit is 1.3 x 10-6 mol/L. The modified electrode has a well-repeatability and can enhance the sensitivity for the determination of ascorbic acid, and eliminats the interference of dopamine. It has been applied to the quantitative determination of ascorbic acid in tablet and tomato juice.