Surface materials as reference standards

Studies about standardization of geological samples have been the main goal of analytical research works and have thus contributed to supply data concerning the contents of major, minor and trace elements in samples. As reference standards, silicates and surface materials have been used, the latter being less abundant and the most employed are: bauxite standards NBS-69-a, NBS-69-b and NBS-697 (USA) and BxN(France); soil standards SO-1, SO-2, SO-3, SO-4 (Canada) and Soil-5 (international). Additional contributions to analytical geochemistry will be obtained from works aiming the standardization of samples of weathering materials. Contents of major components (SiO2, Al2O3, Fe2O3 and volatile materials), minor (TiO2, P2O5)and trace elements (Cu, Pb, Zn, Ni, Co, Mn, Y, Zr, Nb, V and Mo) are being determined in two samples of altered basalt, three samples of bauxite and two samples of soils. Among the analytical methods employed in this preliminary phase of the work are the classical methods (gravimetric and titrimetric), colorimetry and X-ray fluorescence analysis. (Author)