聚L-精氨酸修饰玻碳电极测定抗坏血酸

Determination of Ascorbic Acid at Poly(L-Arginine) Modified Glassy Carbon Electrode

用循环伏安法制备了聚L-精氨酸修饰玻碳电极,并研究了抗坏血酸在修饰电极上的电化学行为,建立了测定抗坏血酸的新方法.在pH7.5的磷酸盐缓冲溶液中,抗坏血酸在修饰电极上产生一氧化峰,峰电位为0.050V(对AgA/gCl电极).用线性扫描伏安法测定抗坏血酸的线性范围为5.0×10-6～5.0×10-3molL/,检出限为2.0×10-6molL/.用于药物中抗坏血酸的测定,结果满意。

A poly（L-arginine） chemical modified electrode（PLA/GCE） was fabricated by electrochemical immobilization of L-arginine on a glassy carbon electrode（GCE） through cyclic voltammetry（CV） The voltammetric behavior of ascorbic acid and a cyclic vohammetric method for the determination of ascorbic acid have been studied at the poly（L-arginine） modified electrode. In pH 7.5 phosphate buffer solution, the modified electrode gave a oxide peak at 0. 050 V （vs. Ag/AgC1）. The linear response was obtained in the range of 5.0 ×10^6 - 5.0 ×10^-3 mol/L. The detection limit was 2. 0 ×10^-6 mol/L. The method has been successfully applied to the determination of ascorbic acid in drug with satisfactory results.