基于溶胶-凝胶普鲁士蓝膜修饰玻碳电极电催化氧化测定水果中抗坏血酸

Determination of Ascorbic Acid in Fruits Based on Its Electrocatalytic Oxidation at Sol-Gel Coated Prussian Blue Modified Glassy Carbon Electrode

摘要: 制备了一种溶胶-凝胶普鲁士蓝膜修饰玻碳电极,研究了抗坏血酸在该电极上的电催化氧化作用,建立了测定抗坏血酸的方法.在磷酸缓冲溶液(pH 5.0)中,在2.5×10-5~3.2×10-3mol·L-1范围内,抗坏血酸的浓度与氧化峰电流呈线性关系,相关系数为0.999 5,检出限为7×10-6mol·L-1.该修饰电极具有制备简单、灵敏度高、响应速度快、稳定性和重现性好等特点.方法已用于水果中抗坏血酸的测定,所得结果与药典法测得结果一致.

Abstract: Sol-gel prussian blue membrane modified glassy carbon electrode was prepared.Electrocatalytic oxidation of ascorbic acid at the modified electrode was studied and a new method for the determination of ascorbic acid was established.In a phosphate buffer of pH 5.0,the oxidation peak current was proportional to the concerntration of ascorbic acid in the range of 2.5×10-5-3.2×10-3mol·L-1,with a correlation coefficient of 0.999 5,and a detection limit of 7×10-6mol·L-1.This modified electrode was characterized by its simple preparation,high sensitivity,good stability and reproducibility,as well as fast response.In the determination of ascorbic acid in 4 fruit samples,the results obtained were in comformity with the results obtained by pharmacopoeia method.