Determination of geochemical background for environmental studies of soils via the use of HNO3 extraction and Q-Q plots

The procedure proposed in this study is based on the extraction of elements in soils by analytical grade HNO3, the distribution of the elemental data displayed on probability graphs (Q-Q plots) and the visualization of the results spatially by GIS software. The applicability of the procedure is demonstrated in an urban area and its surroundings (Kavala, northern Greece). A major (Ca) and a trace (Ag) element are used as examples in order to demonstrate the applicability of the proposed procedure. Normal probability and lognormal probability plots of Ca and Ag show that their concentrations are lognormally distributed and that their geochemical baseline and anomaly threshold values can be calculated with the aid of their geometric mean and geometric deviation. The advantages of the proposed procedure are simplicity, comprehensiveness, and low cost. It can be applied to environmental geochemical studies of soils in a variety of areas. © 2010 Springer-Verlag.This work was partially carried out in the framework of PEGEFA 2005SGR-00795 Research Consolidated Group, funded by AGAUR-DURSI,Generalitat de Catalunya.Peer Reviewe