Electrochemical ultra-micro sensors for the determination of synthetic and natural antioxidants in edible vegetable oils

Abstract

We describe the application of square wave voltammetry at ultramicroelectrodes for the determination of natural antioxidants (α, δ, and γ tocopherols), and tert-butyl hydroxytoluene in edible vegetable oils. Tocopherol determinations were performed in benzene/ethanol (1:2) + 0.1 mol L-1 H2SO4 + oil samples at a carbon fiber disk ultramicroelectrode, and tert-butyl hydroxytoluene was determined in acetonitrile (ACN) + 0.1 mol L-1 (C4H9)4NF6P at a Pt band ultramicroelectrode after performing its extraction from the oil sample with ACN. Recovery percentages determined by the standard additions method were in the range from 92% to 102 %, with variation coefficients between 0.5% and 4%. Antioxidant concentrations calculated by this methodology were in good agreement with those values declared by the manufacturers.