AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Controlled HOx and NOx Production via Alkyl Nitrite Photolysis for Use in Oxidation Flow Reactor Studies of Secondary Organic Aerosol Formation Pathways
ANDREW LAMBE, Penglin Ye, William Brune, Anthony Carrasquillo, Jordan Krechmer, Paola Massoli, Roy Lee III Mauldin, Zhe Peng, Jonathan Raff, Jose-Luis Jimenez, Douglas Worsnop, Aerodyne Research, Inc.
Abstract Number: 182 Working Group: Aerosol Chemistry
Abstract Oxidation flow reactors (OFRs) that use low-pressure mercury lamps to produce hydroxyl (OH) radicals are an emerging technique for studying the formation and oxidative aging of organic aerosols. In these flow reactors, ozone is photolyzed at λ = 254 nm to produce O(1D) radicals, which react with H2O and nitrous oxide (N2O) to produce OH and NO, respectively. Here, we develop a complementary method adapted from previous environmental chamber and kinetics studies that uses photolysis of alkyl nitrites at λ = 254 or λ > 350 nm to produce hydroperoxyl (HO2) radicals and nitric oxide (NO) followed by the reaction NO + HO2 → NO2 + OH. We present experimental and model characterization of OH, HO2, NO and nitrogen dioxide (NO2) concentrations that are generated via photolysis of several C1 – C4 alkyl nitrites in the Potential Aerosol Mass OFR. We demonstrate proof of principle using chemical ionization mass spectrometer measurements of highly oxidized multifunctional compounds generated from the OH oxidation of biogenic volatile organic compounds.