摘要:
利用电沉积法制备了聚对苯二酚/铜(PHQ/Cu)复合膜修饰电极,并采用循坏伏安法探究了抗坏血酸(AA)在该电极上的电催化氧化行为。结果表明,与裸电极、PHQ修饰电极相比,PHQ/Cu复合膜修饰电极对AA具有更好的催化作用,表明两种修饰剂对AA的电催化氧化有良好的协同催化作用;在0.1 mol/L磷酸盐缓冲溶液(pH=4.35)中,AA的氧化峰电流与其浓度在5×10-4~1.0×10-1 mol/L范围内呈良好的线性关系,线性方程为lgI=0.7364lgc+1.6932,R2=0.9959,检出限为2.0×10-5 mol/L。该复合膜修饰电极在冰箱内贮存9 h,其电化学信号基本保持不变,且共存物几乎不干扰AA的测定,表明电极具有良好的稳定性和较强的抗干扰能力,可以用于饮料中AA含量的测定,回收率在95.5%~109.1%之间。
Abstract:
In this paper,the electrodeposition method was used to prepare the glass carbon electrode modified with PHQ/Cu composite film(PHQ/Cu/GCE)and the electrocatalytic oxidation behavior of ascorbic acid(AA)on the electrode was studied by using cyclic voltammetry. The experimental results showed that compared with the bare GCE and PHQ/GCE,PHQ/Cu/GCE had better catalytic activity towards AA,which indicated that the composite film had a good synergistic catalytic action towards the electrooxidation reaction of AA. At the same time,in 0.1 mol/L phosphate buffer solution(pH=4.35),the oxidation peak current of AA was in proportion to its concentration in the range of 5×10-4~1.0×10-1 mol/L. The regressive equation was lgI=0.7364lgc+1.6932,R2=0.9959,with a detection limit of 2.0×10-5 mol/L. The modified electrode was stored in refrigerator for 9 h,the electrochemical signal remained unchanged,and the coexisting substances hardly interfered with the determination of AA,which demonstrated that the modified electrode had good stability and strong anti-interference ability. Furthermore,the modified electrode was successfully used to determine the content of AA in drink with recoveries of 95.5%~109.1%.
百度学术
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