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| Titel |
Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products |
| VerfasserIn |
R. E. Schwartz, L. M. Russell, S. J. Sjostedt, A. Vlasenko, J. G. Slowik, J. P. D. Abbatt, A. M. Macdonald, S. M. Li, J. Liggio, D. Toom-Sauntry, W. R. Leaitch |
| 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 ; 10, no. 11 ; Nr. 10, no. 11 (2010-06-08), S.5075-5088 |
| Datensatznummer |
250008515
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| Publikation (Nr.) |
 copernicus.org/acp-10-5075-2010.pdf |
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| Zusammenfassung |
| Submicron particles collected at Whistler, British Columbia, at
1020 m a.s.l. during May and June 2008 on Teflon filters were analyzed by Fourier
transform infrared (FTIR) and X-ray fluorescence (XRF) techniques for
organic functional groups (OFG) and elemental composition. Organic mass (OM)
concentrations
ranged from less than 0.5 to 3.1 μg m−3, with a project mean and
standard deviation of 1.3±1.0 μg m−3 and
0.21±0.16 μg m−3 for OM and sulfate, respectively. On average, organic
hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and
23% of OM, respectively. Ketone, amine and organosulfate groups
constituted 6%, 5%, and <1% of the average organic aerosol
composition, respectively. Measurements of volatile organic compounds (VOC),
including isoprene and monoterpenes from biogenic VOC (BVOC) emissions and
their oxidation products (methyl-vinylketone / methacrolein, MVK/MACR), were
made using co-located proton transfer reaction mass spectrometry (PTR-MS).
We present chemically-specific evidence of OFG associated with BVOC
emissions. Positive matrix factorization (PMF) analysis attributed 65% of
the campaign OM to biogenic sources, based on the correlations of one factor
to monoterpenes and MVK/MACR. The remaining fraction was attributed to
anthropogenic sources based on a correlation to sulfate. The functional
group composition of the biogenic factor (consisting of 32% alkane,
25% carboxylic acid, 21% organic hydroxyl, 16% ketone, and 6%
amine groups) was similar to that of secondary organic aerosol (SOA)
reported from the oxidation of BVOCs in laboratory chamber studies,
providing evidence that the magnitude and chemical composition of biogenic
SOA simulated in the laboratory is similar to that found in actual
atmospheric conditions. The biogenic factor OM is also correlated to dust
elements, indicating that dust may act as a non-acidic SOA sink. This role
is supported by the organic functional group composition and morphology of
single particles, which were analyzed by scanning transmission X-ray
microscopy near edge X-ray absorption fine structure (STXM-NEXAFS). |
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