Resumo

BOLANOS, Karen Liceth et al. Optimizing adsorption voltammetric technique (Adsv) in determining of amaranth on carbon printed electrodes: Effect of surfactants on sensitivity. Rev. Soc. Quím. Perú [online]. 2014, vol.80, n.2, pp.115-123. ISSN 1810-634X.

A simple and sensitive electroanalytical method is optimized by determining amaranth(E123) by AdSV on a screen printed carbon electrode (Dropsens DRP-154). E123 is deposited by adsorption on the electrode surface and the current peak measured by square wave (SWV). The electrode is characterized by cyclic voltammetry (CV) in the presence of cationic surfactant cetylpyridinium bromide (CPB) where E123 is oxidized to 0.62 V by diffusion, increasing near 100% the peak current in the presence of CPB. The experimental variables such as pH, concentration of surfactant (C_CPB) adsorption time (T_ads) and adsorption potential (E_ads), as well as potential interference, were studied. Under optimal conditions (pH 2.0; C_CPB 1.x 10-5 molL-1; t_ads 90s; E_ads 0.10 V) the peak current is proportional to the concentration of E123 between 0.10 to 2.0 x 10^-6 molL-1, with a detection limit of 0.18 x 10^-7 molL^-1. The relative standard deviation for a solution containing 1.0 x 10^-5 molL^-1 of E123 was 1.0% for seven equal measures. The method was validated with a water sample doped with E123. Finally the method was applied in the determination of amaranth in samples of sodas.

Palavras-chave : Amaranth; adsorption voltammetric; cetylpiridinium bromide.

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