M. Goreti F. Sales,* Cláudia Martins, M. Fátima Barroso, M. Carmo V.F. Vaz, M. Beatriz P. Oliveira, C. Delerue-Matos
Requimte/Instituto Superior de Engenharia do Porto, Rua Dr. António Bernardino de Almeida nº 431, 4200-072 Porto, Portugal
Abstract
The voltammetric behaviour of glutamate at a gold electrode was studied by means of cyclic voltammetry. From 2.6 to 11.5 pH values, glutamate originated a single cathodic peak. Potential of the peak, Ep, was -0.8 V, and it was independent from pH. The reduction of glutamate was found irreversible and mainly controlled by diffusion.
An analytical approach for analysis of glutamate by means of square wave voltammetry was developed. Plots of current versus concentration presented a linear behaviour from 2.5×10-4 to 2.7×10-3 M. The detection limit was 6.3×10-5 M. Interference from compounds co-existing with glutamate in food was negligible, and in favour of an application of the proposed method to the analysis of real samples. Determination of glutamate in pure solutions resulted in acceptable deviation from the stated concentration. Relative errors ranged -2.5 to +1.6 %.
Keywords: glutamate, gold electrode, voltammetry, flavour enhancer, food
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*Corresponding author. E-mail address: mgf@isep.ipp.pt
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