. Nitrate Radical Reactions with Select Biomass Burning Compounds Using a Dark Oxidation Flow Reactor

Abstract
Biomass Burning (BB), including wildfire and agricultural burning, emits a complex mixture of volatile organic compounds (VOCs) that are oxidized by OH, O3, and the nitrate radical (NO3). Oxidation of BBVOCs by NO3 is not well studied when compared to OH and O3. Because fires emit both the NOx precursor that forms NO3 and reactive BBVOCs, nighttime BB plume aging by NO3 is expected to be rapid. Additionally, some NO3-BBVOC reactions are known to be substantial sources of secondary organic aerosol. We have developed a dark oxidation flow reactor (OFR) to investigate reactions of NO3 with important BBVOCs. The OFR exploits the thermal lifetime of N2O5 to provide a relatively constant source of NO3 during the residence time in the flow tube. Variation of this residence time together with the distribution of observed reaction products provides a probe of the reaction mechanism. Here we present the OFR design as well as preliminary insights into the gas phase products and mechanisms of NO3 with catechol, phenol, and 2,5-dimethylfuran.