Enhancement of voltammetric determination of quinizarine based on the adsorption at surfactant-adsorbed-layer in disposable electrodes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Processo FAPESP: 05/00382-4

Screen-printed carbon electrode (SPCE) surface was easily altered through spontaneous hydrophobic interactions with cationic surfactant cetyltrimethylammonium bromide (CTAB) to form a surfactant-adsorbed-layer. This finding combined the practicality of the SPCE with the CTAB's anti-fouling ability and preconcentration properties as a suitable alternative to determine the quinizarine in fuel samples using the square-wave voltammetric technique. Under optimized experimental conditions the electroanalytical method presented a linear response from 5.00 x 10(-7) to 6.00 x 10(-6) mol L-1 (r = 0.998) with a detection limit of 2.70 x 10(-7) mol L-1. The methodology was successfully applied in the dye marker quantification in diesel oil and kerosene samples, without matrix interference, with recoveries values highly satisfactory and ranged between 84.0% and 98.7%. (C) 2014 Elsevier Ltd. All rights reserved.