The Mössbauer study of atmospheric iron-containing aerosol in the coarse and PM2.5 fractions measured in rural site

•Mössbauer spectroscopy used to study of aerosol in PM2.5 and coarse fraction.•Monomer and polymeric aquated iron species observed in the Mössbauer spectra.•Superparamagnetic behavior of iron-containing atmospheric aerosol.•Ultra fine hematite particles were observed mostly in PM2.5 fraction. The size-resolved iron-containing atmospheric aerosol was measured by Mössbauer spectroscopy. The particulate matter (PM) was size-segregated into aerosol 2.5μm (coarse fraction). The Mössbauer spectra at room temperature show components assigned to mono- and polymeric species which are products related to hydrolysis of ferric solutions in the atmosphere. In order to extract reliable information regarding the quadrupole splittings necessary for identification of iron-containing compounds, the histogram method was used for evaluation of the Mössbauer spectra. The value and distribution of quadrupole splitting (QS) parameters obtained by this method suggests that the ultra fine particles (