聚吡咯修饰铂电极快速测定植物油中维生素E的研究

Determination of V_E in vegetable oils by polypyrole film modified platinum electrode

采用恒电位聚合的方法,在0.9V(vs.Ag/AgC l)电位下,修饰铂电极使其表面形成对苯磺酸掺杂聚吡咯薄膜。通过循环伏安法扫描发现,在0.696V处维生素E在该修饰电极表面形成一个明显的氧化峰。利用微分脉冲伏安技术作为检测方法,在最佳实验条件下,维生素E的氧化峰电流与其浓度在6×10-6～3×10-3mol/L范围内呈良好的线性关系,相关系数为0.9963,最低检出限为2×10-6mol/L(S/N=3)。应用该电极可以简便、准确、快速测定植物油中维生素E含量。

The polypyrol film modified platinum electrode doped with p-Tolunesulfonic acid was prepared by constant potential at 0.9V versus Ag/AgCl. Cyclic voltammogram of VE showed a well defined oxidation peak at 0.696V. Using differential pulse voltammetry method, the peak currents were found increase linearly with Ve concentration and detection limit of VE was found to be 2 × 10^-6mol/L（ S/N = 3）with a linear range of 6 × 10^-6 3 × 10^-3mol/L. The modified electrode could be used in simple, practical, rapid detection of the quantification of VE in vegetable oils.