制备石墨烯修饰电极建立电化学方法实现对抗坏血酸的测定。采用电化学还原技术，通过一步电沉积制备石墨烯修饰玻碳电极（ERGO/GCE），并用循环伏安法研究抗坏血酸（ascorbic acid，AA）在该修饰电极上的电化学行为，结果表明，所制备的石墨烯修饰电极较裸玻碳电极对抗坏血酸有显著的电催化效果。在pH=6.5的磷酸盐缓冲溶液中，AA在-0.4 V~0.8 V扫描电位范围内有1个不可逆的氧化峰出现。在优化的实验条件下，AA的浓度在1.7×10-3 mol/L~2×10-5 mol/L范围内与其氧化峰电流值呈良好的线性关系，相关系数为0.991，最低检出限为9×10-6 mol/L（S/N=3）。探究了修饰电极的稳定性、抗干扰性，结果表明电极稳定性良好，抗干扰能力较强。用此修饰电极对橙汁中的AA含量进行检测，加标回收率在97.95%~98.68%之间。用本文建立的电化学方法可用于橙汁中AA的测定，结果比较满意。

A graphene modified electrode was prepared to establish an electrochemical method for the determination of ascorbic acid. The graphene modified electrode (ERGO/GCE) was prepared by one-step electrodeposition using electrochemical reduction technique. Electrochemical behavior of ascorbic acid (ascorbic acid, AA) on the modified electrode was investigated by cyclic voltammetry (cyclic voltammetry, CV). The results showed that the as-prepared graphene modified electrode had obvious electrocatalytic effect against ascorbic acid. In the phosphate buffer solution with ph=6.5, AA has an irreversible oxidation peak in the range of -0.4~0.8 V scanning potential. Under the optimized experimental conditions, the concentration of AA is linearly related to its oxidation peak current in the range of 1.1×10-3 mol/L~2×10-5 mol/L, the correlation coefficient was 0.991, and the lowest detection limit was 9×10-6 mol/L (S/N 3). The stability and anti-interference of the modified electrode were investigated. The results showed that the electrode had good stability and strong anti-interference ability. The content of AA in fruit orange beverage was detected by modified electrode, and the recovery rate was between 97.95%~98.68%. Electrochemical method established in this paper can be used for the determination of AA in orange juice, and the results are satisfactory.

江西省自然科学基金项目（20161BAB216097）；江西省教育厅科学技术研究项目（GJJ161035）