ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Sequential and Single Step Extraction Procedures Used for Fractionation of Selenium in Soil Samples

I. Hagarová, M. Žemberyová, and D. Bajčan

Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Sk-842 15 Bratislava

E-mail: hagarova@fns.uniba.sk

Received: 17 October 2003

Abstract: The sequential extraction and single step extraction procedures were used to assess potentially bioavailable selenium from Slovak soils. The used sequential extraction allows to differentiate live forms of selenium bound in soils (exchangeable fraction and fraction bound to carbonates, fraction bound to manganese-iron oxides, fraction bound to organic matter, fraction bound to humid compounds, fraction bound to sulfides) and residual fraction. The single step extraction of soil with 0.1 mol dm^-3 KH₂PO₄ + K₂HPO₄ (pH 7.0; P-buffer) releases different forms of selenium: soluble, adsorbed, ligand-exchangeable, and plant protein-bound. Application of the P-buffer to soils resulted in a low recovery of selenium (3-12 %) when compared to the total selenium content of the respective soils. The total selenium was determined after total decomposition using HNO₃ and HF acids. The determination of selenium in the individual fractions and total selenium was performed by now injection hydride generation atomic absorption spectrometry (FI-HGAAS).

Full paper in Portable Document Format: 592a93.pdf

Chemical Papers 59 (2) 93–98 (2005)