Seasonal variation of particulate lipophilic organic compounds at nonurban sites in Europe

Abstract

[1] Atmospheric aerosol samples, collected continuously during a sampling period longer than 1 year at six rural and background sites representing oceanic, rural and continental environments across Europe, were extracted, fractionated and analyzed by gas chromatography/mass spectrometry. The detailed organic speciation of the aerosol samples enabled the choice of some key compounds to assess the contribution of different sources. Lipophilic molecular markers were identified, including vehicle exhaust constituents, meat smoke tracers, phytosterols of higher photosynthetic plants and wood smoke components, especially from coniferous vegetation. The lowest concentrations and a quasi absence of seasonal cycle were observed at the oceanic background site of Azores. The highest values and a greater number of compounds were registered at the two continental lower-level sites. Aveiro (a rural site close to the small coastal Portuguese city of Aveiro) and K-puszta (Hungarian plains) both presented a seasonal variation with winter maxima attributable to a sizable contribution of wood-burning and meatcooking sources. At the mountain sites (Puy de Dôme, Schauinsland and the high alpine summit of Sonnblick), concentrations maximized during summer as a result of the decoupling of the lower layers from the midtroposphere with wintry weather and the influence of boundary layer air masses during the warm season.

Polycyclic aromatic hydrocarbons and their oxygenated derivatives in the urban atmosphere of Athens

“…Each extract was fractionated into compound classes (aliphatic hydrocarbons, PAHs, carbonyl compounds, n-alkanols, fatty acids) using flash chromatography [22]. A 30 cm × 1 cm column containing 1.5 g of activated silica gel (150 • C for 3 h) and 5 solvents of increasing polarity (n-hexane, toluene, dichloromethane, ethyl acetate, methanol, formic acid) were used to provide 5 fractions of the extract.…”

A review of atmospheric chemistry observations at mountain sites

“…Higher mass concentrations have been found during summer when convection occasionally transports polluted air masses to JFJ and SNB. At different non-urban sites located along a west-east transect in Europe including SNB, Oliveira et al (2007) showed year-round variations of lipophilic particulate organic compounds emitted from vehicle exhaust constituents, meat smoke tracers, phytosterols of higher photosynthetic plants, and wood smoke components. They determined that the concentrations at SNB maximized during summer, whereas an absence of seasonal variation was observed at the oceanic site.…”

Contribution from Selected Organic Species to PM2.5 Aerosol during a Summer Field Campaign at K-Puszta, Hungary

“…Oliveira et al [8] measured 200 compounds by GC/MS in their weekly PM 2 samples from the K-puszta site for a one-year period (July 2002 to September 2003) and only 4% of the OC was explained. In the study of Kourtchev et al [9] at a forested site in Jülich, only around 2.5% of the OC was explained by the GC/MS compounds measured for PM 2.5 samples from a warm and dry period in summer 2003.…”