玻碳电极吸附循环伏安法测定维生素B_2

Studies on adsorptive cyclic voltammetry of VB_2 on glassy carbon electrode

目的 :研究维生素B2 在玻碳电极表面吸附的电化学行为及定量分析方法 .方法 :玻碳电极在 8.0mol/LHNO3 介质中 ,于 + 0 .6～ + 2 .0V (vs.SCE)的电位范围内进行循环扫描电活化后 ,维生素B2 在电极表面具有很强的吸附性 ,在底液为 0 .0 5mol/L柠檬酸 + 0 .1mol/LNa2 HPO4 (pH =4 .9)的介质中 ,吸附电位 - 0 .3V ,在 0～ - 0 .7V的范围内 ,以 90mV/s的速度进行循环伏安扫描 .结果 :实验表明VB2 在电极表面具有可逆吸附波的特征 ,VB2 浓度与峰电流在 6.0× 10 - 8～ 7.0× 10 - 6 mol/L之间成线性关系 ,检测限为 1.0× 10 - 8mol/L .结论 :建立了维生素B2 在玻碳电极表面的电化学分析方法 ,将该法运用于实际样品药片中VB2 含量的测定 ,获得满意的结果 .

Aim: The electrochemical behaviors of vitamin B 2 on glassy carbon electrode were studied. Methods: The electrode was activated in 8.0 mol/L HNO 3 solution at electrode potentials ranging +0.6～+2.0 V (vs.SCE). The experiment was carried out in a solution containning 0.05 mol/L lemon acid and 0.1 mol/L Na 2HPO 4 (pH=4.9) at-0.3 V. After ten minutes adsorption, scanning at 90 mV/s was carried out in the range of 0.0～0.7 V, changing the concentrations of VB 2 solution from 6.0×10 -8 mol/L to 7.0×10 -6 mol/L. Results: It was found that VB 2 showed characteristic reversible adsorption on the surface of glassy carbon electrode. There was a linear relation between VB 2 concentration and peak current between 6.0×10 -8～7.0×10 -6 mol/L. The detection limit was 1.0×10 -8 mol/L. Conclusion: The proposed method was applied to determination actual samples. The result was satisfactory.