Voltammetric determination of butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate and tert-butylhydroquinone by use of chemometric approaches

The voltammetric behavior of synthetic food antioxidants, such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate (PG) and tert-butylhydroquinone (TBHQ), at a glassy carbon electrode in solution of 0.1 mol l(-1) perchloric acid containing 1% methanol has been investiga ted. The obtained linear sweep voltammograms (LSV) showed that all these fo ur compounds have well-defined oxidation waves with peak potentials of 629, 818, 599 and 501 mV for BHA, BHT, PG and TBHQ, respectively. Linear calibr ation graphs were also obtained in the concentration ranges of 0.5-15.0, 0. 5-8.0, 1.0-15.0 and 1.0-15.0 mg l(-1) for BHA, BHT, PG and TBHQ, respective ly However, the voltammetric peaks of these antioxidants seriously overlap and it is difficult to determine them individually from a mixture without p rior separation. In this work, a method for simultaneous determination of t hese antioxidants, based on their oxidation at the grassy carbon electrode, with the aid of chemometric approaches, such as classical least squares (C LS), principal component regression (PCR) and partial least squares (PLS), has been developed. The method was applied to determine the four antioxidan ts in a set of synthetic mixtures and several commercial food samples; in g eneral, satisfactory results were obtained. (C) 2000 Elsevier Science B.V. All rights reserved.