用多壁碳纳米管修饰玻碳电极为工作电极循环伏安法测定辛硫磷  

Cyclic Voltammetric Determination of Phoxin Using Multi-wall Carbon Nano-tube Modified Glassy Carbon Electrode as Working Electrode

作　　者：杨书昌[1] 师真 刘拥军[1] 王光灿[1] 

机构地区：[1]云南大学化学与化学工程学院,现代分析测试中心,昆明650091 [2]昆明市疾病控制预防中心,昆明650216

出　　处：《理化检验（化学分册）》2011年第1期50-53,共4页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：将多壁碳纳米管（MWCNT′s）置于硝酸-硫酸（1＋1）溶液中回流6 h使之净化及功能化。取MWCNT′s 5 mg置于超纯水10 mL中经超声振荡20 min制得其悬浮液,取悬浮液10μL滴加在玻碳电极（GCE）表面,经自然干燥后即得用MWCNT′s修饰的玻碳电极（MWCNT′s/GCE）。基于此修饰电极对辛硫磷的催化还原反应,提出了蔬菜中辛硫磷的循环伏安测定法,在pH 4的乙酸盐支持电解质溶液中,在电位0.78 V（对SCE）处可见明显的还原峰,且其峰电流值与辛硫磷浓度在5.0×10-8-1.0×10^-6mol·L^-1之间呈线性关系。应用此法分析了两件蔬菜样品,并以此试样为基体加入标准溶液对方法进行回收及精密度试验,测得其回收率的平均值和相对标准偏差（n=5）分别依次为100.3%,96.5%及3.7%,3.2%。Multi-wall carbon nano-tubes（MWCNT′s） were purified and functionalized by refluxing in HNO3-H2SO4（1＋1） for 6 h.A dispersion of 5 mg of the MWCNT′s in 10 mL of high-purity water was prepared by ultrasonic vibration for 20 min,and 10 μL of the dispersion were added dropwise onto the surface of glassy carbon electrode（GCE）.After air-drying,the modified electrode（abbreviated as MWCNT′s/GCE） was obtained and used in cyclic-voltammetric determination of phoxim in vegetables,based on its catalytic action on the electro-reduction of phoxim at the electrode.In a supporting electrolyte of acetate buffer of pH 4,a significant reduction peak was observed at 0.78 V（vs.SCE）,and linear relationship between values of reduction peak current and concentration of phoxim was kept in the range of 5.0×10^-8 to 1.0×10^-6mol·L^-1.Two samples of vegetables were analyzed for their phoxim contents by this method.Values of average recovery and RSD′s（n=5） found by standard addition method using these samples as matrixes were 100.3%,96.5% and 3.7%,3.2% respectively.

关 键 词：多壁碳纳米管 修饰电极 循环伏安法 辛硫磷 

分 类 号：O657.1[理学—分析化学]