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| Titel |
A method for detecting the presence of organic fraction in nucleation mode sized particles |
| VerfasserIn |
P. Vaattovaara, M. Räsänen, T. Kuhn, J. Joutsensaari, A. Laaksonen |
| 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 ; 5, no. 12 ; Nr. 5, no. 12 (2005-12-14), S.3277-3287 |
| Datensatznummer |
250003193
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| Publikation (Nr.) |
 copernicus.org/acp-5-3277-2005.pdf |
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| Zusammenfassung |
| New particle formation and growth has a very important role in many climate
processes. However, the overall knowlegde of the chemical composition of
atmospheric nucleation mode (particle diameter, d<20 nm) and the lower end
of Aitken mode particles (d≤50 nm) is still insufficient. In this work,
we have applied the UFO-TDMA (ultrafine organic tandem differential mobility
analyzer) method to shed light on the presence of an organic fraction in the
nucleation mode size class in different atmospheric environments. The basic
principle of the organic fraction detection is based on our laboratory
UFO-TDMA measurements with organic and inorganic compounds. Our laboratory
measurements indicate that the usefulness of the UFO-TDMA in the field
experiments would arise especially from the fact that atmospherically the
most relevant inorganic compounds do not grow in subsaturated ethanol vapor,
when particle size is 10 nm in diameter and saturation ratio is about 86%
or below it. Furthermore, internally mixed particles composed of ammonium
bisulfate and sulfuric acid with sulfuric acid mass fraction ≤33%
show no growth at 85% saturation ratio. In contrast, 10 nm particles
composed of various oxidized organic compounds of atmospheric relevance
are able to grow in those conditions. These discoveries indicate that it is possible to
detect the presence of organics in atmospheric nucleation mode sized
particles using the UFO-TDMA method. In the future, the UFO-TDMA is expected
to be an important aid to describe the composition of atmospheric
newly-formed particles. |
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