10-羟基喜树碱在碳纳米管-离子液体修饰电极上的电催化氧化及电分析方法  

Electrocatalytic oxidation of 10-hydroxycamptothecin at multi-wall carbon nanotube-ionic liquid modified glassy carbon electrode and its electroanalytical application

作　　者：闫莉莉[1] 高云涛[2] 李晓芬[2] 刘萍[2] 

机构地区：[1]铜仁学院材料与化学工程学院,铜仁554300 [2]云南民族大学化学与生物技术学院,昆明650500

出　　处：《分析试验室》2015年第7期777-782,共6页Chinese Journal of Analysis Laboratory

基　　金：梵净山特色动植物资源重点实验室基金项目(黔教KY[2011]232号);梵净山主要经济植物种质基地建设及其开发利用研究基金项目(黔教合重大专项字[2012]018号)资助

摘　　要：用多壁碳纳米管（MWCNTs）和亲水性离子液体N-乙基吡啶四氟硼酸盐（[EtPy]BF4）作修饰剂，构置了修饰玻碳电极（MWCNTs-[EtPy]BF4／GCE），并应用电镜扫描法（SEM）和电化学阻抗法（EIS）对MWCNTs-[EtPy]BF4／GCE进行了表征。MWCNTs在[EtPy]BF。离子液体中能有效分散，增加了电极表面的活性位点，与裸GCE和MWCNTs-DMF／GCE相比，MWCNTs-[EtPy]BF4／GCE电导率最高。在pH6．8的PBS缓冲溶液中，用循环伏安法（CV）和差分脉冲伏安法（DPV）研究了10-羟基喜树碱在该修饰电极上的电化学行为，建立了一种测定10-羟基喜树碱注射液中10-羟基喜树碱含量的新方法。10-羟基喜树碱在MWCNTs-[EtPy]BF4／GCE上出现一对灵敏、可逆的氧化还原峰，峰电位差（△Ep）为40mV，与MWCNTs-DMF／GCE相比减小了80mV；10-羟基喜树碱在MWCNTs-[EtPy]BF4／GCE上的氧化、还原峰电流响应分别是在MWCNTs-DMF／GCE上的3．3倍和2．0倍，表明MWCNTs-[EtPy]BF4／GCE对10-羟基喜树碱的氧化还原反应有良好的电催化作用。在20—500mV／s扫速范围内，氧化还原峰电流均与扫速平方根（v^1/2）呈线性关系，表明该电极反应过程受扩散控制。在DPV曲线上，10-羟基喜树碱的氧化峰电流与其浓度在5．0×10^-6-1．8×10^-4g／L范围内呈良好的线性关系，检出限为1．0×10^-6g／L。方法用于10-羟基喜树碱药物的含量测定，RSD为2．9％～3．5％，加标回收率曲9R6％-105％。A new modified glassy carbon electrode（ MWCNTs-[Et Py]BF4/ GCE） was fabricated by using multiwall carbon nanotube and hydrophilic ionic liquid N-ethylpyridinium tetrafluoroborate as modifiers. The characteristic of MWCNTs-[Et Py]BF4/ GCE was characterized by scanning electron microscopy（ SEM） technique and electrochemical impedance spectroscopy（ EIS）. The results showed that MWCNTs had an effective dispersibility in [Et Py]BF4ionic liquid,and increased the active site of the electrode surface; The conductivity was highest comparing to the bare GCE and MWCNTs-DMF/ GCE. The electrochemical behavior of 10-hydroxycamptothecin at the modified electrode was investigated in a PBS buffer solution（ pH = 6. 8） by cyclic voltammetry（ CV） and differential pulse voltammetry（ DPV）,and a novel method for the determination of 10-hydroxycamptothecin in 10-hydroxycamptothecin injection was thus established. A couple of sensitive and quasireversible redox peaks of 10-hydroxycamptothecin were observed on the MWCNTs-[Et Py]BF4/ GCE. At MWCNTs-[Et Py]BF4/ GCE,the peak-to-peak potential separation（ ΔEp） of 10-hydroxycamptothecin was 40 m V; compared with MWCNTs-DMF/ GCE,the ΔEpdecreased by 40 m V. Furthermore,the oxidation and reduction peak current responses of 10-hydroxy-camptothecin at MWCNTs-[Et Py]BF4/ GCE were 3. 3 times and2. 0 times of these at MWCNTs-DMF/ GCE,respectively. These indicated the MWCNTs-[Et Py]BF4/ GCE possessed an excellent electrocatalytic activity for the redox of 10-hydroxycamptothecin. The redox peak currents were linear to scan rates in the range of 20 - 500 m V/ s,suggesting that the electrode process of 10-HCPT was controlled by diffusion. In the DPV curves,the oxidation peak current was linearly related to the concentration of10-hydroxycamptothecin in the range of 5. 0 × 10- 6- 1. 8 × 10- 4g/ L,with a detection limit of 1. 0 × 10- 6g/ L.The method was applied in the determination of 10-hydroxycamptothecin in samples. The relative standard deviation was between 2. 9% and 3.

关 键 词：10-羟基喜树碱 碳纳米管 离子液体 电催化氧化 电分析方法 

分 类 号：TG115.26[金属学及工艺—物理冶金]