EPR investigations of Mn2+, Fe3+ ions and carbonaceous radicals in atmospheric particulate aerosols during their transport over the eastern coast of the English Channel

Electron paramagnetic resonance (EPR) spectroscopy was used to follow the evolution of the chemical forms of manganese and study other paramagnetic species in the atmospheric particulate aerosols at Wimereux, a French station located on the eastern coast of the English Channel. In parallel, Graphite Furnace Atomic Absorption Spectrometry (GFAAS) was used to measure the metal concentrations. Fe concentration values are common in North Sea sites, but those of Mn are quite higher due to the presence of an important local source of Mn. EPR spectra have evidenced isolated Fe3+ and Mn2+ ions and carbonaceous products with variable intensities according to the wind directions. Amounts of paramagnetic species and carbonaceous products are maximum for continental winds and minimum for marine winds. Three Mn types were identified depending on the sampling distance from the source of emission and the size of the particles.