Molecular Chemical Speciation of HOMs in Urban Aerosols with FIGAERO CI-APi-TOF and LC-ESI-Orbitrap High-Resolution Mass Spectrometers

LEE TISZENKEL, Asadullah Shoaib, Sameera White, Rachel Hurley, Yue Zhang, Shanhu Lee, University of Alabama Huntsville

     Abstract Number: 420
     Working Group: Aerosol Chemistry

Abstract
The Southeastern United States has a unique atmospheric condition for atmospheric organic aerosol formation due to strong oxidation reactions of abundant biogenic and anthropogenic VOCs under various pollutant conditions such as SO2 and NOx. At present, there are very limited methods that can determine the molecular identification of organic aerosols, especially highly oxygenated organic molecules (HOMs). We will present the molecular level chemical identification of aerosol-phase HOMs with two high-resolution mass spectrometer techniques using off-line filter samples collected in Huntsville, Alabama (an urban site with strong emissions of biogenic VOCs). The LC (Liquid chromatography) – ESI (electrospray ionization) Orbitrap high-resolution mass spectrometer provides detailed chemical identification of organic species containing C, H, O, N, and S, with MS/MS analysis. The CI-APi-TOF (Chemical Ionization Atmospheric Pressure interface Time-of-Flight) mass spectrometer with the FIGAERO (Filter Inlet for Gases and AEROsols) can measure volatility of various HOMs. Thus, these two high-resolution mass spectrometer measurements can complement each other and provide unique molecular insights on HOMs in urban organic aerosols for a better understanding of their formation processes.