L-抗坏血酸在锂-对苯二甲酸修饰电极上的电化学行为及其测定

利用电沉积法制备了1种[Li-BDC]/GC修饰电极,并用循环伏安法和交流阻抗法研究了L-抗坏血酸（AA）在修饰电极上的电化学行为.结果表明,与裸玻碳电极相比,该修饰电极对AA具有更高的电催化活性,其氧化峰电流增大了约1.6倍.探讨了不同实验条件对电极性能的影响,在最佳实验条件下,检测AA药物浓度的线性范围为3.0×10-7～2.5×10-3 mol·L-1,线性相关系数为0.9990,检出限为6.0×10-8 mol·L-1（信噪比为3∶1）,回收率为97.2%～100.4%.该修饰电极具有较好的稳定性和重复性,并用于维生素C片剂中AA的含量测定,结果与药典方法一致.

Electrochemicalbehavior and determination of L-ascorbic acid on lithium-terephthalic acid modified electrode

A Lithium-terephthalic acid（Li-BDC） modified glassy carbon electrode was fabricated by electrodeposition method. The electrochemical performance of L-ascorbic acid（AA） on the modified e- lectrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The ex- perimental results showed that the [Li-BDC]/GC electrode has a more excellent electrocatalytic ac- tivity for the oxidation of AA than that of GC electrode. Compared with GC electrode, the anodic peak current of AA on FLi-BDC-]/GC electrode increased about 1.6 times. The effects of the different ex- perimental conditions on the electrochemical behaviors of AA were explored. Under the optimum con- ditions of preparation and experiment,the linear calibration curve of AA was obtained in a wide range of 3.0×10-7～2.5×10-3 mol·L-1 with a correlation coefficient of 0. 9990 and the detection limit of 6.×10-8 mol·L-1 （S/N∶1）. The recovery was from 97.2% to 100.4%. The modified electrode showed a good stability and repeatability. This method can be used to determine AA in vitamin C tab- lets with satisfactory results.