Avaliação da presença e lixiviação de metais tóxicos em amostras de três marcas comerciais de alginatos

A material widely used in dental offices for making dental impressions is alginate. The objective of this work was to study three different brands of alginate by fluorescence and X-ray diffraction and extractions using the method of Tessier, followed by the determination of the concentrations of metals in the extracts by atomic absorption spectrometry. Through X-ray fluorescence, was observed that the most representative in the samples are Si, Ca, K, S, Al, Mg, Fe and P, and the sum of these elements reaches values above 97%. By X-ray diffraction, it was observed that the peak was indicative of a higher concentration of SiO2 (cristobalite) and the compounds found in all specimens were CaSO4.2H2O, SiO2 (cristobalite) and SiO 2. The assessment of mobilization (leaching) of metals performed by the method of Tessier and its comparison with the CONAMA 430/11 has shown potential risks of improper disposal of such material in the environment due to concentrations (above PMV) of lead in the fractions of the metal on the carbonates and organic matter.