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| Titel |
Monoterpene oxidation products and organosulfates in aerosols during BEARPEX 2007 and 2009 |
| VerfasserIn |
Marianne Glasius, Kasper Kristensen, David R. Worton, Allen H. Goldstein |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250037658
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| Zusammenfassung |
| Organosulfate esters of oxidation products of monoterpenes and isoprene have been identified
in aerosols from both laboratory and field studies. While the exact route of formation of
organosulfates is still ambiguous, these compounds pose an interesting coupling between
anthropogenic emissions and biogenic oxidation products in secondary organic aerosols
(SOA). We present measurements of monoterpene oxidation products, organosulfates and
nitroxy organosulfates in aerosols collected during the Biosphere Effects on Aerosols and
Photochemistry Experiment (BEARPEX) in California during late summer 2007 and summer
2009. The study site was located in a Ponderosa pine plantation affected by regional transport
of air pollutants. Particles (PM2.5) were collected as one night-time and two daytime samples
per day using a high volume sampler. After extraction of filters, polar organic compounds
were analysed by HPLC coupled through an electrospray inlet to a quadrupole
time-of-flight mass spectrometer (qTOF-MS). Standards of adipic, cis-pinic and pinonic
acids were used for quantification, while camphor sulphonic acid was used as a
surrogate standard for organosulfate compounds. Organosulfate esters can be identified
from their MS-fragments (HSO4- and SO3-) and the isotopic pattern of sulphur.
Concentrations of adipic acid and the terpene oxidation products cis-pinic acid and pinonic
acid (from α- and β-pinene) were quantified. The relative concentrations between
samples of terpenylic acid, diterpenylic acid and 2-hydroxyterpenylic acid were also
investigated. Organosulfate esters and nitroxy organosulfate esters of α-pinene, β-pinene,
limonene and isoprene, as well as their oxidation products, were identified based on
their molecular mass and fragmentation patterns. Concentrations of some nitroxy
organosulfate esters generally increased during night compared to day-time. Their
formation thus seems to be related to reactions involving nitrate radicals at night-time. |
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