Hannover 2010 – wissenschaftliches Programm

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SYMS: Symposium New methods of mass spectroscopy and their application in the environmental science

SYMS 1: Session I

SYMS 1.4: Hauptvortrag

Donnerstag, 11. März 2010, 12:00–12:30, A 001

Organic compounds in the atmosphere: insights from Isotope Mass Spectrometry — •Astrid Kiendler-Scharr, Iulia Gensch, Thorsten Hohaus, Beatrix Kammer, and Werner Laumer — ICG-2: Troposphäre, Forschungszentrum Jülich GmbH, Jülich, Germany

Organic compounds are emitted into the atmosphere from both anthropogenic and biogenic sources. Volatile organic compounds (VOC) undergo photochemical conversion in the atmosphere and serve as precursors for ozone and aerosols. Analyzing the ratio of stable isotopes in atmospheric samples of both gas and particulate phase organics can provide insight into the extent of chemical and physical processing that an air mass has experienced. Oxidation processes in general result in fractionation between the heavy and light isotopes favoring the light isotopes to accumulate in the product whereas the reactant enriches with the heavy isotopes due to the kinetic isotope effect (KIE). As a result, compounds formed from oxidation processes in the atmosphere are isotopically lighter whereas their precursors are enriched with heavy isotopes. After having determined the KIE in laboratory studies it is possible to evaluate the origin of VOCs or their processing in the atmosphere. The talk will summarize the state of the art of isotope mass spectrometry in atmospheric VOC and aerosol studies.