AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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Identification of Organic Hydroperoxides and Organic Peroxyacids from α-pinene Secondary Organic Aerosol
SHOUMING ZHOU, Jean Rivera-Rios, Frank Keutsch, Jonathan Abbatt, University of Toronto, Toronto, Canada
Abstract Number: 277 Working Group: Aerosol Chemistry
Abstract Previous studies have shown that organic peroxides (including organic hydroperoxides and peroxyacids, ROOH) could account for a significant fraction of the secondary organic aerosol (SOA) generated from atmospheric oxidation of biogenic volatile organic compounds (VOCs). Moreover, it has been proposed that ROOH compounds are involved in oligomer formation and aerosol aging processes. However, due to the unstable nature of ROOH species, studies on their identification and quantification are very limited.
In this work, we report an experimental study of an off-line method for the identification of ROOH products from ozonolysis of α-pinene. SOA was generated in a 1 m3 Teflon chamber, collected on a filter, and then extracted with methanol. The solution was directly infused into the ionization source utilizing positive-ion atmospheric pressure chemical ionization (APCI) of a tandem mass spectrometer (MS/MS, Thermo Endura). A characteristic neutral loss of 51 Da (arising from loss of NH3+H2O2) in the MS/MS analysis of commercially available ROOH was also observed in a series of products in α-pinene SOA, indicating the formation of ROOH. The possible identities and formation mechanisms of these ROOH products in the ozonolysis of α-pinene will be discussed.