Keggin型磷钨酸/2-氨基吡啶聚合膜修饰电极的电化学性质及对维生素B_2的电催化  

Investigation of Electrochemical Properties of Keggin-type Phosphotungstic Acid/2-Amino Pyridine Electropolymerized Modified Electrode and Its Electrocatalysis Towards Vitamin B_2

作　　者：刘传银[1] 高川[1] 

机构地区：[1]襄樊学院化学工程与食品科学学院,湖北襄阳441053

出　　处：《分析测试学报》2012年第2期174-179,共6页Journal of Instrumental Analysis

基　　金：湖北省自然科学基金(2011CDB321);十堰市科技与开发计划(2010nt05);襄樊学院教学研究项目(JY201145;hyjy201102)

摘　　要：制备了Keggin型磷钨酸/2-氨基吡啶电聚合复合膜修饰电极,研究了该复合膜修饰电极的电化学性质。结果表明,在BR缓冲溶液中,该复合膜修饰电极显示出3对氧化还原峰,对应于表面电沉积的磷钨酸的电化学作用,其电化学行为受表面吸附控制。该电极对维生素B2(VB2)具有良好的电催化作用,根据VB2的电化学行为,推断出了可能的电极反应机理,计算出VB2在该电极上的电荷转移系数为0.357,电荷转移速率常数为0.042 s-1,推断其在该电极上的行为为准可逆过程。在2.4×10-6～1.0×10-4 mol/L和1.0×10-4～5.5×10-4 mol/L范围内峰电流与VB2浓度呈良好的线性关系,其检出限为1.4×10-6 mol/L。该电极显示出良好的稳定性和重现性,用于复合维生素药片中VB2含量的测定,结果满意。A novel Keggin-type phosphotungstic acid H7[P（W2O7）6]/2-amino pyridine electropolymerization（PW/PAP） modified glassy carbon electrode was fabricated by electrodepositing H7[P（W2O7）6] onto 2-amino pyridine electro-polymerized glassy carbon electrode.The electrochemical behaviors of PW/PAP modified electrode were investigated by cyclic voltammetry.It is found that there are three redox peaks appeared in the potential range from-0.8 V to 0.2 V in BR buffer solution.The modified electrode showed a good electrocatalysis towards the electro-oxidation of vitamin B2（VB2）.The electrochemical behavior of VB2 was surface-controlled.The electron transfer coefficient and rate constant were calculated to be 0.357 and 0.042 s-1,respectively,indicating that the electrochemical reaction of VB2 was a quasi-reversible process.Under the optimal conditions,there was a good linear relationship between the peak currents and VB2 concentrations in the concentration range of 2.4×10-6-1.0×10-4mol/L and 1.0×10-4-5.5×10-4 mol/L,with a detection limit of 1.4×10-6 mol/L.The composite electrode had good stability and reproducibility,and was used in the determination of VB2 in composite vitamin tablets with satisfactory results.

关 键 词：磷钨酸/2-氨基吡啶电聚合膜 维生素B2 电化学催化 

分 类 号：O657.1[理学—分析化学] Q563.2[理学—化学]