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| Titel |
Physico-chemical characterization of SOA derived from catechol and guaiacol – a model substance for the aromatic fraction of atmospheric HULIS |
| VerfasserIn |
J. Ofner, H.-U. Krüger, H. Grothe, P. Schmitt-Kopplin, K. Whitmore, C. Zetzsch |
| 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 ; 11, no. 1 ; Nr. 11, no. 1 (2011-01-03), S.1-15 |
| Datensatznummer |
250009052
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| Publikation (Nr.) |
 copernicus.org/acp-11-1-2011.pdf |
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| Zusammenfassung |
| Secondary organic aerosol (SOA) was produced from the aromatic precursors
catechol and guaiacol by reaction with ozone in the presence and absence of
simulated sunlight and humidity and investigated for its properties as a
proxy for HUmic-LIke Substances (HULIS). Beside a small particle size, a
relatively low molecular weight and typical optical features in the UV/VIS
spectral range, HULIS contain a typical aromatic and/or olefinic chemical
structure and highly oxidized functional groups within a high chemical
diversity. Various methods were used to characterize the secondary organic
aerosols obtained: Fourier transform infrared spectroscopy (FTIR)
demonstrated the formation of several carbonyl containing functional groups
as well as structural and functional differences between aerosols formed at
different environmental conditions. UV/VIS spectroscopy of filter samples
showed that the particulate matter absorbs far into the visible range up to
more than 500 nm. Ultrahigh resolved mass spectroscopy (ICR-FT/MS)
determined O/C-ratios between 0.3 and 1 and observed m/z ratios between 200
and 450 to be most abundant. Temperature-programmed-pyrolysis mass
spectroscopy (TPP-MS) identified carboxylic acids and lactones/esters as
major functional groups. Particle sizing using a
condensation-nucleus-counter and differential-mobility-particle-sizer
(CNC/DMPS) monitored the formation of small particles during the SOA
formation process. Particle imaging, using field-emission-gun scanning
electron microscopy (FEG-SEM), showed spherical particles, forming clusters
and chains. We conclude that catechol and guaiacol are appropriate
precursors for studies of the processing of aromatic SOA with atmospheric
HULIS properties on the laboratory scale. |
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