Investigation of Extraction Methods for the Assessment of the Pseudo-Total Concentration of Potentially Toxic Elements in Moderately Contaminated Soils of Central Greece

The aim of this research was the investigation of the effectiveness of several extractants as possible assessment of pseudo-total As, Pb and Cu concentrations in moderately contaminated soils of Central Greece. In soils of 3 different land uses (forest, agricultural and industrial), various extraction procedures were performed using simple and low-cost extraction solutions, i.e. inorganic acids (HCl and H3PO4), salts (NH4NO3 and CH3COONH4), organic chelating agents (as ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA)) and an alkaline agent (NaOH). The findings were reported as percentages to their pseudo-total concentrations obtained using Aqua Regia. The species of As (III), As (V) and total As(T) were extracted. Higher percentages of As concentrations were extracted using H3PO4 concluding that this may be the most effective of the extractants used. On the other hand, the percentages of the EDTA-extracted Pb and Cu, in forest soils with high organic matter content, were the highest. In forest soils, also, satisfactory correlations between EDTA-extracted Pb and Cu versus their pseudo-total content were observed. Finally, significant correlations among As, Pb and Cu concentrations in some soil extracts and soil physicochemical parameters were obtained, suggesting that the extractability of As, Pb and Cu may depend upon soil characteristics in the study area.