以水杨酸为模板分子,采用循环伏安法电聚合形成聚吡咯膜,以固定电位过氧化法去除印迹分子,制备了水杨酸分子印迹膜电极。本印迹电极能促进水杨酸电氧化过程,有效地避免结构类似物(如苯甲酸)对其测定的干扰。循环伏安法用于电化学检测,当富集时间为10min,磷酸盐缓冲溶液的pH=6.86时,在1.0×10^-6~2.0×10^-3mol/L浓度范围内,水杨酸氧化峰电流与其浓度呈良好的线性关系,检出限为0.8μmol/L,用分子印迹膜电极对加标样品进行分析,回收率为94.6%~103.4%。
Molecular imprinted film modified glassy carbon electrode was prepared by electrochemical polymerization of pyrrole with the cyclic voltammetry in the presence of template molecular, salicylic acid. The template molecules were removed from the modified electrode surface by over-oxidized at 1.3V in the solution of 0.2 mol/L Na2HPO4 for 10 min. The modified electrodes can effectively promote electrochemical oxidation process of salicylic acid in the surface of electrode and avoid interference of structural similar substance such as benzoic acid. Cyclic vohammetry was employed in the electrochemical measurements. The experimental results show that the optimum acidity of background solution is pH 6. 86 and the optimum incubation is 10 rain. The linear response curve was obtained from 1.0×10^-6 mol/L to 2.0×10^-3 mol/L, with the detection limit of 8.0×10^-7 mol/L. The imprinted electrode has been applied to the analysis of salicylic acid in the simulated samples with recovery rates ranging from 94.6% to 103.4%.