硫酸奎宁在SDBS-[bupy]PF_6修饰碳糊电极上的电催化氧化及电分析方法

Electrocatalytic oxidation and its electrochemical determination of quinine sulfate at SDBS-[bupy]PF_6 modified carbon paste electrode

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5.0×10-6～1.0×10-4mol·L-1和1.0×10-4～1.0×10-3mol·L-1呈线性关系,检测限为3.5×10-7mol·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）with sodium dodecyl benzenesulfonate（SDBS）and N-butylpyridinium hexafluorophosphate（[bupy]PF6）modified carbon paste electrode（CPE）.At the same time,an electrochemical quantitative determination had been established.Methods：Cyclic voltammetry（CV）,chronocoulometry（CC）,chronoamperometry（CA）,electrochemical Impedance spectral（EIS）and square wave voltammetry（SWV）were investigated.Results：Electrochemical experimental results showed 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 present 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 wave 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：SDBS-[bupy]PF6 / CPE can catalyze the oxidation of QS well.Furthermore,this method can be applied in the test of quinine content with simple manipulation.