维生素E在碳糊电极上催化伏安法的研究

ADSORPTIVE CATALYTIC VOLTAMMETRIC BEHAVIOR OF VITAMIN E AT THE CARBON PASTE ELECTRODE

将维生素E的皂化产物通过Fe(Ⅲ)氧化为醌型化合物生育酚红,在0.10mol/LBrit-ton-Robinson-乙醇溶液(pH=3.8)中,应用自制碳糊电极为工作电极,通过开路富集及Fe(Ⅲ)的催化氧化,采用阴极溶出伏安法对维生素E进行了测定.测定结果表明溶液中维生素E含量在4.5×10-7～3.8×10-9mol/L范围内与还原峰电流iPa呈良好的线性关系,检出限为8.0×10-10mol/L.根据这一结果确定了维生素E的催化伏安测定方法,并且研究了生育酚红在自制碳糊电极上的催化伏安行为和电极反应机理.

A new vitamin E adsorptive catalytic voltammetry was developed for the determination of vitamin E at a CPE in the current paper and the oxidant of the reaction is Fe（Ⅲ）. By treating with Fe（Ⅲ） , vitamin E is transformed into Tocopherol. Extractive stripping voltammetric behavior is observed at the CPE. The vitamin E is adsorbed on the CPE in 0. 10 mol/L B-R-50% ethanol buffer solution （pH 3.8）, linear response is obtained in the range from 3.8×10^-9 mol/L to 4. 5× 10^-7 mol/L of vitamin E. Detection limit of this method is found to be 8.0×10^-10 mol/L. The mechanism of the electrode reaction was discussed in detail.