Identification of the metal contamination degree in soil by speciation

In this study, selective and sequential extraction procedures were carried out for different soil samples taken from Elazığ, to determine toxic and carcinogen elements such as cadmium, chromium, copper, nickel and lead with atomic absorption spectrometry. In selective extraction procedure, CH3COONH4, KNO3, CH3COOH, CH3COONa, Na2 H2EDTA .2H2O, Na4P2O7, Acetate buffer (pH 5), NH2OH HCl, NH2OH HCl as extraction reagents were used. In sequential extraction procedure (three step), firstly, exchangeable and bound to carbonates with CH3COOH (pH 2.85), secondly, reducible and bound to Fe-Mn oxides with NH2OH HCl (pH 2), and thirdly, oxidizable, bound to organic matter and sulfides with H2O2 and CH3COONH4 (pH 2) were used to determine the elements fractions. The sequential extraction procedure?s modified by changing the stirring time. While Cd and Cu concentrations in mobile phases of the studied soil samples were found considerably, Ni and Cr concentrations in the most samples were observed as immmobile forms. Plant samples as well as soils were analysed for the studied metals, and the observed results were compared with the metal concentrations in different fractions of soils. Consequently, only Cu and Ni concentrations exceed the limit levels according speciation results although Cr, Ni and Cu concentrations exceed the limit levels according to total metal concentrations.Key words: Soil, Cadmium, Chromium, Copper, Nickel, Lead, Selective Extraction, Sequential Extraction, Atomic Absorption Spectrometry.