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2.4×10-6～1.0×10-4mol/L和1.0×10-4～5.5×10-4mol/L范围内峰电流与VB2浓度呈良好的线性关系,其检出限为1.4×10-6mol/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( W207)6]/2-amino pyridine electropoly-merization ( 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 x 10-6 -1.0 x 10-4 mol/L and 1.0 X10-4 -5. 5 x 10-4 mol/L, with a detection limit of 1.4 x 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.
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