卡马西平在nano-TiO_2/[BnMIM]PF_6修饰碳糊电极上的电催化氧化及电分析方法

Electrocatalytic Oxidation of Carbamazepine at nano-TiO_2/PF_6 Modified Carbon Paste Electrode and Its Electrochemical Determination

运用循环伏安法(CV)、计时电流法(CA)、计时库仑法(CC)、方波伏安法(SWV)研究了卡马西平(CBZ)在纳米二氧化钛(nano-TiO2)与离子液体1-苄基-3-甲基咪唑六氟磷酸盐([BnMIM]PF6)复合修饰碳糊电极(nano-TiO2-[BnMIM]PF6/CPE)上的电化学行为、电化学动力学性质及电分析方法。研究结果表明,与CPE相比,CBZ在nano-TiO2-[BnMIM]PF6/CPE上的氧化峰电位略有负移,氧化峰电流急剧增大,表明nano-TiO2-[BnMIM]PF6/CPE对CBZ的电化学氧化具有良好的催化作用。在10～1 000 mV.s-1扫速范围内,CBZ的氧化峰电流(Ipa)与扫速的平方根(v1/2)呈良好线性,表明CBZ在nano-TiO2-[BnMIM]PF6/CPE上的电极反应受扩散控制。用SWV法测得CBZ的氧化峰电流与其浓度在2.0×10-5～5.0×10-4 mol.L-1以及5.0×10-4～1.0×10-3 mol.L-1范围内呈良好线性,检出限(S/N=3)为4.3×10-7 mol.L-1。采用该方法对市售卡马西平片进行测定,其相对标准偏差(RSD)为0.36%～0.77%,加标回收率为98%～104%。

Electrochemical behaviors, electrochemical kinetics and electrochemical determination of carbamazepine （CBZ） at nano-titanium dioxide （ nano-TiO2 ） and 1-benzyl-3-methylimidazole hexaflu- orophosphate （ [ BnMIM ] PF6 ） modified carbon paste electrode （ nano-TiO2 - [ BnMIM ] PF6/CPE ） were investigated by cyclic vo]tammetry （ CV）, chronocoulometry （ CC ）, ehronoamperometry （CA） and square wave vohammetry（SWV）. The experimental results showed that the oxidation peak poten- tial of CBZ was shifted negatively at nano-TiO2 - [ BnMIM ] PF6/CPE and the oxidation peak current was greatly increased than that on CPE, which indicated that nano-TiO2 - [ BnMIM ] PF6/CPE could catalyze the oxidation of CBZ well. The plot of oxidation peak current versus the square root of scanning rate in the potential range of 10 - 1 000 mV s-1 showed a good linear relationship, as expected for a diffusion-controlled feature of the electrochemical process for CBZ at nano-TiO2 - [ BnMIM ] PF6/ CPE. The results of square wave ,voltammetry （SWV） indicated that the oxidation peak current was linearly proportional to the concentration of CBZ in the range of 2.0 ×10^- 5 - 5.0 ×10^-4 mol · L^-1 and 5.0 ×10^-4 _ 1.0 ×10^-3 mol· L^-1 , with a detection limit of 4. 3 ×10^-7 mol · L^-1. The method was applied in the determination of carbamazepine （CBZ） content in commercial pills, with relative standard deviations of 0.36% - 0.77% and spiked recoveries of 98% - 104% .