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| Titel |
Secondary organic aerosol formation and composition from the photo-oxidation of methyl chavicol (estragole) |
| VerfasserIn |
K. L. Pereira, J. F. Hamilton, A. R. Rickard, W. J. Bloss, M. S. Alam, M. Camredon, A. Muñoz, M. Vázquez, E. Borrás, M. Ródenas |
| 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 ; 14, no. 11 ; Nr. 14, no. 11 (2014-06-03), S.5349-5368 |
| Datensatznummer |
250118763
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| Publikation (Nr.) |
 copernicus.org/acp-14-5349-2014.pdf |
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| Zusammenfassung |
| The increasing demand for palm oil for uses in biofuel
and food products is leading to rapid expansion of oil palm agriculture.
Methyl chavicol (also known as estragole and 1-allyl-4-methoxybenzene) is an
oxygenated biogenic volatile organic compound (VOC) that was recently identified
as the main floral emission from an oil palm plantation in Malaysian Borneo.
The emissions of methyl chavicol observed may impact regional atmospheric
chemistry, but little is known of its ability to form secondary organic
aerosol (SOA). The photo-oxidation of methyl chavicol was investigated at
the European Photoreactor chamber as a part of the atmospheric chemistry of
methyl chavicol (ATMECH) project. Aerosol samples were collected using a
particle into liquid sampler (PILS) and analysed offline using an extensive
range of instruments including; high-performance liquid chromatography mass
spectrometry (HPLC-ITMS), high-performance liquid chromatography quadrupole
time-of-flight mass spectrometry (HPLC-QTOFMS) and Fourier transform ion
cyclotron resonance mass spectrometry (FTICR-MS). The SOA yield was
determined as 18 and 29% for an initial VOC mixing ratio of 212 and
460 ppbv (parts per billion by volume)
respectively; using a VOC:NOx ratio of ~5:1. In
total, 59 SOA compounds were observed and the structures of 10 compounds
have been identified using high-resolution tandem mass spectrometry. The
addition of hydroxyl and/or nitro-functional groups to the aromatic
ring appears to be an important mechanistic pathway for aerosol formation.
This results in the formation of compounds with both low volatility and high
O:C ratios, where functionalisation rather than fragmentation is mainly
observed as a result of the stability of the ring. The SOA species observed
can be characterised as semi-volatile to low-volatility oxygenated organic
aerosol (SVOOA and LVOOA) components and therefore may be important in
aerosol formation and growth. |
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