Previous studies showed that native pasture in the “coal energetic” region of Candiota, RS state/Brazil was considerably contaminated by fluorine. In this work 21 different species of native pasture plants were identificated and their fluorine concentrations evaluated. The determinations were performed by ion-selective electrode technique into the resulting solutions of pasture sample decomposition with a H2O2 + HNO3 mixture. Pasture samples collected at three different sites from the vicinity of the coal-fired power plant (UTPM) showed values between 2.17 and 15.18 ppm of F-. The fluorine concentrations of the pastures from Candiota were higher than the measured levels in reference samples. The different absorption and retention ability of this element by the studied species is evidenced by the variability of measured concentration levels.
fluorine; pasture; ion-selective electrode; pollution