Determination of chromium and zinc speciation in airborne particulate matter by x-ray absorption near-edge structure G. Gerelmaa(1), J. Osan(2), A. Migliori(3), D. Shagjjamba(4), and C. Streli(1) (1) Vienna University of Technology, Vienna, Austria Environmental Physics Department, Hungarian Academy of Sciences,Budapest, Hungary (2) Nuclear Science and Instrumentation Laboratory, Physics section, IAEA, Seibersdorf, Austria (3) Underline presenter’s name, and add email address (4) Nuclear Research Center, National University of Mongolia, Ulaanbaatar, Mongolia streli@ati.ac.at This study presents the first time the result of elemental speciation in atmospheric particulate matter (APM or PM) samples from Ulaanbaatar, Mongolia. Samples of PM2.5 (fine) and PM10-2.5 (coarse) were examined by X-ray Fluorescence analysis using PAnalytical Espilon 5 spectrometer to investigate concentrations of chromium (Cr) and zinc (Zn) in the atmosphere. X-ray Absorption Near-edge Structure (XANES) spectrometry was used to obtain speciation information of elements. Analyses of recorded data using linear combination fitting method were applied to identify potential compounds in samples The preliminary XANES results show that major chemical forms of Cr in the both fine and coarse fractions are chromium(III) sulfate (Cr2(SO4)3) and chromium(III) oxide (Cr2O3). For chemical forms of Zn, the contribution of Zn sulfate (ZnSO4) was dominating to the fine fractions, whereas Zn franklinite (ZnFe2O4) found to be dominating compounds to the coarse fractions.