硫脲在10-甲基吩噻嗪修饰碳糊电极上的电催化氧化及电分析方法研究  

Electrocatalytic oxidation of thiourea at a 10-methylphenothiazine modified carbon paste electrode and its practical analytical application

作　　者：王春梅[1] 高作宁[1] 

机构地区：[1]宁夏大学能源化工重点实验室,化学化工学院,银川750021

出　　处：《分析试验室》2009年第7期1-4,共4页Chinese Journal of Analysis Laboratory

基　　金：宁夏高等学校科学研究(200623)项目资助

摘　　要：研究了硫脲（Thiourea，Tu）在10-甲基吩噻嗪修饰碳糊电极（MPT／CPE）上的电催化氧化行为。结果表明，Tu在裸碳糊电极（CPE）上的直接电化学氧化过程十分迟缓，MPT／CPE对Tu的电化学氧化具有良好的催化作用。用计时电流法（CA）测定了Tu在MPY／CPE上的电极过程动力学参数，测得电荷传递系数口=0．61，电催化氧化反应的速率常数k=（1．96±0．10）×104（mol／L）-·s^-1。用方波伏安法（swv）测得催化氧化峰电流与Tu浓度在1．0×10^-6～8．0×10^-3mol／L范围内呈良好的线性关系，线性回归方程为Ipa（μA）=10．836c（10^-3mol／L）＋5．326，R=0．9984，检出限为2．2×10^-7mol／L（S／N=3）。方法可用于Tu的电化学法测定。A 10-methylphenothiazine modified carbon paste electrode （MPT/CPE） was used to study electrochemical oxidation of thiourea （Tu）. It was found that thiourea itself showed a very poor electrochemical response at a carbon paste electrode （CPE）, and the electrochemical behaviors of Tu could be greatly improved by using the MPT/CPE,which enabled a sensitive electrochemical determination of the substrate thiourea. The kinetic parameters of the electrode reaction were evaluated by using cyclic voltammetry （CV） and chronoamperometry （CA）. Electron transfer coefficient is 0.61. The reaction rate constant for catalytic oxidation was evaluated as （ 1.96 ＋ 0.10） × 10^4 （mol/L） ^-1·s^- 1 by using chronoamperometry （CA）. The catalytic oxidation peak current of thiourea vs. its concentration had a good linear relationship in the concentration range of 1.0 × 10^-6 - 8.0 × 10^-3 mol/L with the correlation coefficient of 0.9984, and the detection limit of 2.2 × 10^-7 mol/L was obtained by square wave voltammetry （SWV）. The results can be applied to the electrochemical determination of thiourea.

关 键 词：硫脲 10-甲基吩噻嗪 碳糊修饰电极 电催化氧化 电化学动力学 

分 类 号：O557.1[理学—热学与物质分子运动论] O647[理学—物理]