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1D - Soil and Sediment Contamination (TUP/18) Step forward on mercury speciation in soil and sediment samples. XANES as a technique for the study of real samples. Gaona, Xavier1, 2, Bernaus, A.1, Calmano , W.2, Valiente , M.1, 1 Grup de Tècniques de Separació en Química, Barcelona, Spain2 Environmental Science and Technology, Hamburg, Germany ABSTRACT- XAFS techniques have been applied to the determination of different mercury species in soil and sediment samples. The feasibility of these techniques based in X-Ray absorption has been demonstrated in previous studies, while the acquired knowledge has been utilized to the analysis of real samples. From XAFS techniques, XANES (X-Ray Absorption Near Edge Spectroscopy) has been chosen because of its high power considering fingerprint adjustments, and in consequence speciation capacity. The data treatment has been performed with the computer program SpecMANGER. This program allows the complete data treatment in both transmittance and fluorescence modes. Equally, the user has the possibility of averaging several spectra, operation that is very necessary when working with diluted samples. Because of the low content on organomercury compounds (HgCH3Cl, HgC6H5Cl, etc), only inorganic mercury compounds (ionic salts, oxides and sulfides) have been considered when building the necessary database. The results obtained will show interesting information regarding both mobility and bioavailability in polluted soil samples. At the same time, the advantages and drawbacks of the technique, and its future possibilities will be presented. Key words: mercury, XANES, speciation, soils |
