Determinação de elementos de maiores e -traço, em mármores de Tete por espectrofometria de absorção atómica - AAS

Abstract

The study done in the present work is part of the project of mineralization of some regions of Tete province, coordinated by the Department of Geology of Eduardo Mondlane University in which we intended to know the contents of various metals in marbles of some regions of geochemical interest in that province. The major elements Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Ti and trace elements Cu, Pb, Rb, Sr and Zn were determined in 16 samples of marble from the regions of Chidue and M'panda Uncua by atomic absorption spectrophotometry ("AAS"), flame photometry (CF) and X-ray fluorescence ("XRF"). The optimization of the instrumental and analytical conditions for the determinations made, in order to validate the methods used, was carried out through the analysis of the reference material Limstone KH (Calcario), supplied by the National Directorate of Geology (DNG). 03% and 0.07-10.3% respectively. A comparison was also made between the results obtained by "AAS" and FC and those obtained by "XRF", using linear regression, concluding that, for the most part, there was no significant difference between the methods used. Based on and comparing the metal contents found and statically evaluated in this work with those obtained in marbles from other regions, both national and international, it can be stated that their values are close except for Mg, whose content in most samples was very high and sometimes close to that of Ca in some samples, which is not common in relation to the content of that metal in most of the marbles already studied. The majority of the studied marbles have Mg contents of about 1% and CaO 35-50%, against 5-20% CaO found in this work.

(TRADUÇAO NOSSA)