1. Universidade Federal do Rio Grande do Norte Instituto de Química, Laboratório de Eletroquímica Ambiental e Aplicada CEP 59078-970 Natal (RN) Brazil
2. Unesp National Institute for Alternative Technologies of Detection Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM) Institute of Chemistry P.O. Box 355 14800-900 Araraquara SP Brazil