NEW VOLTAMMETRIC METHOD FOR DETERMINATION OF PHENANTHRENE IN GROUNDWATER

• Published in: Tchê química Vol. 16; no. 33; pp. 169 - 177
• Main Authors: FERREIRA, A. P. M., TEIXEIRA, E. J. N., OLIVEIRA, I. M. de, PINHEIRO, H. de A., MARQUES, A. L. B.
• Format: Journal Article
• Language: English
• Published: 01.11.2019
• ISSN: 1806-0374; 1806-0374
• DOI: 10.52571/PTQ.v16.n33.2019.184_Periodico33_pgs_169_177.pdf

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.