TXRF Characterization of EDTA Extractable Metals from Soils of Bituminous Sands Occurrence Area, Agbabu, South Western Nigeria

Ethylenediamine Tetra-acetic Acid (EDTA) extractable metals were determined in soils of bituminous sands occurrence area of Agbabu in southwestern Nigeria using Total reflection x-ray Fluorescence (TXRF) technique. Soil samples were collected at two different depths (0-50 and 50-100 cm) along a transverse line cutting across the main road in the study area. Fourteen metals; K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Ce, Eu, Au, Pb and Co were detected in all. However, Co, Pb and Ni were not detected in samples from 0-50 cm depths and Pb and Rb in some samples from 50-100 cm depths. The concentration, mean, range, standard deviation and correlation coefficients were calculated for the detected metals. Moderate correlations were found to exist between K, Ti, Ni, Zn, Rb and Sr; very high correlations between Ca, Cu Pb and Au in 0-50 cm depth samples. In the 50-100 cm depth samples, moderate correlations were observed between Ca, Cu and Zn; between Fe, Ti, Co and Ni. Pb was found to be highly correlated to Ca, Ti, Ni and Sr. This study provides a pre-exploration baseline data in the region and the need for the extension of such a baseline analysis to other environmental sensitive media-water resources, crops and local air quality in the region is emphasized.