论文部分内容阅读
用循环伏安法制备了银掺杂聚L-精氨酸修饰玻碳电极(Ag-PLA/GCE),研究了修饰电极的电化学交流阻抗及维生素B2和维生素B12(Vb2)在Ag-PLA/GCE电极上电化学行为,分析了维生素B2(Vb12)的吸附特性,建立了同时测定Vb2和Vb12的新方法。阻抗图谱说明,由于Ag-PLA修饰,提高了电子传输速率。当Vb2和Vb12同时存在时,在pH 5.0的磷酸盐缓冲溶液中,采用差分脉冲伏安法(DPV法)进行扫描测定,Vb2和Vb12的氧化峰电位分别为-0.470 V和-0.880 V,两种维生素的峰电位差值为:ΔE=0.410 V,不需分离,可同时进行测定。同时测定Vb2和Vb12的线性范围分别为0.10~15.0μmol/L和0.75~12.5μmol/L,检出限分别为0.03μmol/L和0.5μmol/L。方法已用于复合维生素药片中维生素B2和维生素B12的测定。
Silver-doped poly (L-arginine) modified glassy carbon electrode (Ag-PLA / GCE) was prepared by cyclic voltammetry. The electrochemical impedance and electrochemical impedance of vitamin B2 and vitamin B12 (Vb2) / GCE electrode electrochemical behavior, analysis of vitamin B2 (Vb12) adsorption characteristics, the establishment of a simultaneous determination of Vb2 and Vb12 new method. Impedance spectroscopy shows that due to Ag-PLA modification, the electron transport rate is increased. When Vb2 and Vb12 coexist, the differential pulse voltammetry (DPV method) was used to scan the phosphate buffer solution at pH 5.0. The oxidation peak potentials of Vb2 and Vb12 were -0.470 V and -0.880 V, respectively. The peak potential difference between the vitamins is: ΔE = 0.410 V, without separation, can be measured at the same time. The linear range of Vb2 and Vb12 were 0.10 ~ 15.0μmol / L and 0.75 ~ 12.5μmol / L, the detection limits were 0.03μmol / L and 0.5μmol / L, respectively. The method has been applied to the determination of vitamin B2 and vitamin B12 in multivitamin tablets.