Simultaneous Adsorptive Strippin Square-Wave Voltammetric Determination of Vitamin E and Vitamin K in Food Supplements

Abstract

The new voltammetric method has been developed for the simultaneous determination of α-tocopherol and phylloquinone. Adsorptive stripping square wave voltammetry is based on the accumulation of these biologically active compounds onto the freshly polished surface of solid glassy carbon electrode from an aqueous-organic mixture (50 % acetonitrile) and a subsequent voltammetric detection of both vitamins in 0.01 mol L-1 HNO3 containing 0.1 mol L-1 KCl of pH 2.08. Obtained results have shown high sensitivity and short linear range due to self-interaction of vitamins during of adsorption onto surface of the electrode. This electroanalytical method shows that is simple and low-cost in quality control of food supplements.