Selected elements characterization of fine particulate matter PM2.5 using synchrotron radiation XRF

Abstract

Synchrotron radiation-based X-ray fluorescence is a powerful spectroscopy technique that uses synchrotron radiation to induce X-ray fluorescence in samples and provides valuable information on the micron and submicron scale. The characteristics of synchrotron radiation permit implementing multi elemental nondestructive spectrochemical analysis with spatial resolution on the micrometer scale, high efficiency for trace element determination, minimal sample preparation, and reasonable time of analysis. At the IAEA beamline end-station at the Elettra Sincrotrone Trieste, the measurement of airborne particulate PM2.5 samples collected in industrial sites in Indonesia were carried out. The typical reflection 45/45 irradiation geometry was employed for both the micro-XRF and Xray Absorption Near Edge Structure (XANES) measurements. The micro-XRF scanning analyses were performed at different incident beam energies and a total area of about 4 mm×4 mm was analyzed by performing 9×9 measurements with a step size of 0.5 mm with 10 s acquisition time per step. Selected elemental analysis of airborne particulate PM2.5 samples using SR micro XRF were carried out at selected beam energies of 13.5, 12.5 and 7 keV for highly sensitive elemental compositional analysis. Several selected elements such as Na, Mg, Al, Si, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br and Pb were determined. For the determination of the chemical state of certain trace elements, XANES measurements was also performed using the fluorescence mode of analysis at the respective spots identified with the more abundant trace element concentration. XANES spectroscopy was used to determine the oxidation state of arsenic and chromium in APM samples.