硫酸奎宁在SDBS-[bupy]PF6修饰碳糊电极上的电催化氧化及电分析方法___

目的：研究了硫酸奎宁(Quinine sulfate, QS)在十二烷基苯磺酸钠(Sodium dodecyl benzenesulfonate, SDBS)自组装膜与离子液体N-丁基吡啶六氟磷酸盐([bupy]PF6 )复合修饰碳糊电极(SDBS - [bupy]PF6 / CPE)上的电化学行为和电化学动力学性质，建立了QS电化学定量测定方法。方法：循环伏安法(CV)，计时电流法(CA)，计时库仑法(CC)，方波伏安法(SWV)以及电化学交流阻抗法(EIS)。结果：在SDBS - [bupy]PF6 / CPE上，QS发生了受扩散控制的不可逆电化学氧化过程。测得QS在SDBS - [bupy]PF6 / CPE上的电极反应过程动力学参数。用SWV法测得QS氧化峰电流与其浓度在5.0  10-6 ~ 1.0  10-4 molL-1 和1.0  10-4 ~ 1.0  10-3 molL-1呈线性关系，检测限为3.5  10-7 mol•L-1。采用本方法对市售二盐酸奎宁注射液进行了电化学定量测定，RSD在1.3% ~ 3.4 %之间，加标回收率在98.0 % ~ 103 %之间。结论：SDBS - [bupy]PF6 / CPE对QS电化学氧化具有良好的催化作用，该方法可用于市售奎宁类药物含量的电化学定量测定，方法操作简单，测定结果令人满意。

Objective : Studied the electrochemical behaviors and electrochemical kinetic of Quinine sulfate (QS) at Sodium dodecyl benzenesulfonate (SDBS) and N - Butylpyridinium hexafluorophosphate ([bupy]PF6) modified carbon paste electrode (CPE). At the same time, one electrochemical quantitative determination had been established. Methods: Cyclic Voltammetry (CV), Chronocoulometry (CC), Chronoamperometry (CA), Electrochemical Impedance Spectral (EIS) and Square Wave Voltammetry (SWV). Results: Electrochemical experimental results show that QS electrochemical behavior in 0.10 molL-1 PBS exhibits an irreversible electrochemical redox process at SDBS - [bupy]PF6 / CPE. The electron transfer coefficient α, diffusion coefficient D and the electrode reaction rate constant kf were measured, which given the values of 0.76, 2.63 × 10-3 cm2•s-1 and 7.11 × 10-2 s-1. The oxidation peak current of QS versus its concentration have a good linear relationship in the concentration range of 5.0  10-6 ~ 1.0  10-4 molL-1 and 1.0  10-4 ~ 1.0  10-3 molL-1 and the detection limit of 3.5  10-7 mol•L-1 by Square vave voltammetry (SWV) response. The quantitative determination of Quinine dihydrochloride (QD) content was investigated, the relative standard deviation is between 1.3 % ~ 3.4 % and the recoverage is in the range of 98.0 % ~ 103 %. Conclusion: The experimental result indicated that SDBS - [bupy]PF6 / CPE could catalyze the oxidation of QS well. Furthermore, this method can be applied in the test of Quinine content with simple manipulation.

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