巯基乙酸自组装修饰金电极不可逆双安培法对维生素E的测定  

Studies on the Electrochemical Behaviors of Vitamin E on MA-SAMs(Au) Chemically Modified Electrode

作　　者：钟亮[1] 李利军[2] 喻来波[1] 程昊[2] 蔡卓[1] 

机构地区：[1]广西大学化学与化学工程学院,广西南宁530004 [2]广西工学院生物与化学工程系,广西柳州545006

出　　处：《分析测试学报》2008年第8期820-824,共5页Journal of Instrumental Analysis

基　　金：国家自然科学基金资助项目(20665001);广西科学基金资助项目(0640029);广西区研究生教育创新计划资助项目(2006105930502m33)

摘　　要：在裸金电极上制备了巯基乙酸（mercaptoacetic acid）自组装膜修饰电极（MA／SAMs-Au／CME），并对电极的表面结构进行了电化学表征。结果表明该修饰电极对维生素E（VE）的电化学氧化具有明显的增敏作用。该文利用VE在MA／SAMs-Au／CME上的氧化和高锰酸钾（KMnO4）在裸金电极上的还原构建了双安培检测体系，成功地建立了在外加电压为0V条件下流动注射直接测定VE的方法。VE的氧化峰峰电流与其浓度在8．0×10^-6～8．0×10^-5mol／L范围内呈线性关系（r=0．9956，n=6），回归方程为，（nA）=9．87×10^7c＋10，在1×10^-4～1×10^-3mol／L范围内呈线性关系（r=0．9970，n=6），回归方程为，（nA）=1．6×10^7c＋10^4，方法检出限为4．0×10^-7mol／L。连续20次测定1．00×10^-4mol／L的VE溶液，电流值RSD为2．28％，进样频率为每小时进40个样品。对维生素E片剂中VE含量的测定结果比较满意。Preparation of the mercaptoacetic acid （MA）chemically modified electrode（CME） by selfassembling MA on gold electrode surface was reported in this present paper. The electrochemical behaviors of vitamin E （VE） on this CME were investigated. The experimental CME possessed great ability to catalyze the oxidation of VE. Meanwhile, the results showed that this mechanism of VE oxidation was also studied. The flow injection irreversible bi-amperometry analysis method was proposed under the applied potential difference of 0 V. In the 0.05 mol/L sulfuric acid, the oxidative peak current of VE increased linearly with the concentration of VE in the range of 8.0 × 10^ -6 - 8.0 × 10 -5 mol/L（r = 0. 995 6, n = 6）, and the linear regression equation was I（nA） = 9. 87 × 10^7 c ＋ 10; In the range of 1.0 × 10^-4 - 1.0 × 10^-3 mol/L, the linear regression equation was I（nA） = 1.6 × 10^7 c ＋ 10^4（r = 0. 997 0, n = 6 ）. The sampling frequency was 40 samples per hour. The detection limit for VE was 4. 0 × 10^-7 mol/L and the RSD for 20 replicate determination of 1.00 × 10^-4 mol/L VE was 2.28%. The proposed method was applied to the analysis of VE in tablets with satisfactory results.

关 键 词：金电极 巯基乙酸 不可逆双安培法 修饰电极 维生素E 

分 类 号：O657.15[理学—分析化学] Q566[理学—化学]