金属有机骨架材料修饰玻碳电极循环伏安法测定维生素C片中抗坏血酸

Determination of Ascorbic Acid in Vitamin C Tablet by Cyclic Voltammetry at Glassy Carbon Electrode Modified with Metal Organic Framework

摘要: 合成了金属有机骨架材料（Zn-MOFs），通过电沉积方法将Zn-MOFs修饰到玻碳电极表面，制得Zn-MOFs修饰玻碳电极。采用循环伏安法在pH 5的磷酸盐缓冲溶液中以扫描速率100 mV·s^-1对Zn-MOFs修饰玻碳电极进行表征。结果表明：相比于裸玻碳电极，Zn-MOFs修饰玻碳电极提高了抗坏血酸氧化活性。抗坏血酸的线性范围为4×10^-5~1×10^-2mol·L^-1，方法的检出限（3s/k）为6.7×10^-6mol·L^-1。方法用于维生素C片样品的分析，加标回收率为91.0%~109%，测定值的相对标准偏差（n=5）为0.80%~1.9%。

Abstract: The metal organic framework (Zn-MOFs)was synthesized. Zn-MOFs was successfully modified to the glassy carbon electrode surface by electrodeposition method,and then the glassy carbon electrode modified with Zn-MOFs was prepared. The modified electrode was characterized by cyclic voltammetry in phosphate buffer solution of pH 5 at scanning rate of 100 mV·s^-1. It was found that the modified electrode could improve the oxidation activity of ascorbic acid compared with bare glassy carbon electrode. Linearity range of ascorbic acid was found between 4×10^-5mol·L^-1 and 1×10^-2mol·L^-1 with detection limit (3s/k) of 6.7×10^-6mol·L^-1. The proposed method was applied to the analysis of samples of vitamin C tablet, giving values of recovery and RSD's (n=5) in the ranges of 91.0%-109% and 0.80%-1.9% respectively.