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

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。

Sol-gel prussian blue membrane modified glassy carbon electrode was prepare ＆ Electrocatalytic oxidation of ascorbic acid at the modified electrode was studied and a new method for the determination of ascorbic acid was establishe ＆ 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^-6 mol· 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.