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| Titel |
Particle size-resolved source apportionment of primary and secondary organic tracer compounds at urban and rural locations in Spain |
| VerfasserIn |
B. L. Drooge, J. O. Grimalt |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 13 ; Nr. 15, no. 13 (2015-07-15), S.7735-7752 |
| Datensatznummer |
250119898
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| Publikation (Nr.) |
 copernicus.org/acp-15-7735-2015.pdf |
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| Zusammenfassung |
Atmospheric particulate matter (PM) was fractionated in six aerodynamic
sizes, > 7.2, 7.2–3, 3–1.5, 1.5–1, 1–0.5 and < 0.5 μm, using
a cascade impactor. These fractions were collected at urban and rural sites
during warm and cold seasons. Organic tracer compounds, such as levoglucosan,
isoprene, pinene oxidation products, polycyclic aromatic hydrocarbons and quinones, were
analyzed by gas chromatography coupled with mass spectrometry. These analyses
showed that the composition in the smallest size fractions
(< 0.5 μm) was more uniform than in the larger sizes
(7.2> PM > 0.5 μm). Thus, markers of photochemically
synthesized organic compounds or combustion sources, either biomass burning
or traffic emissions, were predominantly observed in the fraction
< 0.5 μm, whereas the larger particles were composed of mixed
sources from combustion processes, vegetation emissions, soil resuspension,
road dust, urban lifestyle activities and photochemically synthesized
organic compounds.
Important seasonal differences were observed at the rural site. In the
< 0.5 μm fraction these were related to a strong predominance of
biomass burning in the cold period and photochemically transformed biogenic
organic compounds in the warm period. In the
7.2 > PM > 0.5 μm fractions the differences involved
predominantly soil-sourced compounds in the warm period and mixed combustion
sources, photochemical products and vegetation emissions in the cold.
Multivariate curve resolution/alternating least squares showed that these
organic aerosols essentially originated from six source components. Four of
them reflected primary emissions related to either natural products, e.g.,
vegetation emissions and upwhirled soil dust, or anthropogenic
contributions, e.g., combustion products and compounds related to urban
lifestyle activities like vehicular exhaust and tobacco smoking. Two
secondary organic aerosol components were identified. They accumulated in the
smallest (< 0.5 μm) or in the larger fractions
(> 0.5 μm) and involved strong or mild photochemical
transformations of vegetation precursor molecules, respectively.
Toxicologically relevant information was also disclosed with the present
approach. Thus, the strong predominance of biomass burning residues at the
rural site during the cold period involved atmospheric concentrations of
polycyclic aromatic hydrocarbons that were 3 times higher than at the
urban sites and benzo[a]pyrene concentrations above legal recommendations. |
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