Evaluation of trace element levels in muscles, liver and gonad of fish species from São Francisco River of the Paraná Brazilian state by using SR-TXRF technique - Espinoza-Quiñones, F. R.; Módenes, A. N.; Palácio, S. M.; Szymanski, N.; Welter, R. A.; Rizzutto, Márcia de Almeida; Borba, C. E.; Kroumov, Alexander D. (Applied Radiation and Isotopes, 2010)