This work proposes a new method for the determination of phenanthrene (FEN) in aqueous medium with a cobalt phthalocyanine modified glassy carbon electrode (ECV / CoPc), using Differential Pulse Voltammetry (VPD), whose oxidation of FEN occurs between 1,3 and 1,4 V. The electrode was modified with a 1x10-3 mol∙L-1 CoPc methanolic solution containing 10% Nafion. For voltammetric measurements in Differential Pulse mode, an amplitude of 0.7V and a scan rate of 0.04V s-1 were used. Experimental parameters were optimized for the purpose of determination of FEN in groundwater collected in a water well of a São Luis-MA fuel station. Under these optimized conditions, an analytical curve was obtained in the 0.49 to 2,4 μM concentration range, with a detection limit of 1,2 x 10-10 mol∙L-1. The method was applied to a real groundwater sample from a water well located at a fuel station, and an average concentration of 0.037 μM FEN was found (n = 5), presenting a variation coefficient of 0.88, indicating good precision. Accuracy was assessed by the recovery test, whose average value was 99.9%. These results indicate that the proposed procedure is a good alternative for the analysis of FEN in natural water.

Bacharel e licenciado em Psicologia pela UFMG, Especialização em Percepção e Planejamento Urbano. Mestre em Gestão e Auditoria Ambiental, especialização em educação ambiental. Consultor em percepção e educação ambiental. Sócio diretor da Alternativa Educação e Manejo Ambiental.

The contamination of water and soil by petroleum hydrocarbons is reported quite frequently, mainly due to accidents involving transport and storage of fuels. Among the most toxic compounds the most volatile benzene, toluene, ethylbenzene and xylene (BTEX). Residues of these compounds can cause serious environmental and public health troubles. Thus, more sensitive, selective and low-cost techniques, focused on the analysis and monitoring of these contaminants are being developed in order to establish operational control and to comply with local laws, but the intellectual property of such technologies is still unknown. The present study shows the panorama about patents, thesis and dissertations which have been already published on this theme. Together, the United States and China hold the largest number of patents, and most of thesis/dissertations describe methodologies for BTEX detection in water, although numerous environmental problems caused by oils in the soil had been reported. Also, the methods based on chromatographic techniques stand out in relation to the other techniques. It was possible to verify important advances in the field of sensors, especially the electrochemical ones, in order to solve the analytical gaps.