Large and small particle size screening of organic compounds in urban air

A gas chromatographic (GC)-mass spectrometric (MS) study of the large (> 7.2 μm) and small (< 0.5 μm) particle fractions of aerosols collected in Barcelona (Catalonia, Spain) has allowed the identification of the major sources of airborne organic matter in urban environments. The extracts have been column chromatography separated in three fractions encompassing aliphatic hydrocarbons, aromatic hydrocarbons+semi-polar compounds, and polar products. The whole analytical procedure has allowed the identification of 186 molecular species that have been grouped according to their precursors. The study has also afforded the characterization of organic source-particle size associations as well as the effects of seasonality on the occurrence of the compounds identified.