Fe and Mn speciation in road dust particles by XAS

The speciation of Fe and Mn in road dust particles, collected on the walls and floor of the ventilation shaft of Traforo del San Bernardo highway tunnel, was studied by means of XAS spectroscopy. Absorption spectra were recorded on BM8 at the ESRF (Grenoble, France) at the Fe and Mn K-edges. Several reference compounds were measured along with the samples, and a standard reference material of road dust (BCR723) was also analyzed. Principal Component Analysis (PCA), Least Square Fitting (LSF), analysis of the edge features, and structural refinements (EXAFS), were applied to give complementary information on the speciation, average oxidation state and local structure of Fe and Mn in the collected samples.