抗坏血酸在离子液体修饰玻碳电极上的电化学行为

摘要

A polished glassy carbon electrode (GCE) was modified with l-butyl-3-methyl imi-dazole tetrafluoroborate (BMIMBF4) ionic liquid to generate BMIMBF4/GCE electrode. The electrochemical behavior of ascorbic acid on the modified BMIMBF4/GCE electrode and bare GCE was investigated in a phosphate buffer solution by cyclic voltammetry. Results indicate that phosphate buffer solution of pH = 5.7 is the optimal substrate solution, and the optimal enrichment time is 120 s. BMIMBF4/GCE possesses excellent electrochemical catalytic activity for the oxidation reaction of ascorbic acid. The oxidation peak current of ascorbic acid is linearly proportional to its concentration in the range of 2.0×10-4 - 1.0×10-2mol/L (r = 0. 998 5), with relative standard deviation of 4.53% (n = 5).%利用离子液体1-丁基-3-甲基咪唑四氟硼酸盐(BMIMBF4)对玻碳电极(GCE)进行修饰,制备了BMIMBF4/GCE电极.在0.1 mol/L的磷酸盐缓冲溶液中,采用循环伏安法研究了抗坏血酸在BMIMBF4/GCE电极和裸玻碳电极(GCE)上的电化学行为.结果表明,pH=5.7的磷酸盐缓冲溶液为最佳测定底液,最佳富集时间为120 s；BMIMBF4/GCE对抗坏血酸的氧化反应有很好的电化学催化作用.抗坏血酸的氧化峰电流与其浓度在2.0×10-4～1.0×10-2 mol/L的范围内呈良好的线性关系,相对标准偏差为4.53％(n=5).