Analysis of organic aerosol in Houston, TX, through aerosol mass spectrometry and proton nuclear magnetic resonance spectroscopy

Organic aerosol from Houston, TX, was measured during August and September of 2006 as part of the Texas Air Quality Study II Radical and Aerosol Measurement Project. Aerosol size and composition were determined using an Aerodyne quadrupole aerosol mass spectrometer, and twenty-nine aerosol filter samples were analyzed using proton nuclear magnetic resonance (H-NMR) spectroscopy to determine the relative concentrations of functional groups. Results indicate that changes in Houston aerosol are due to anthropogenic activities resulting in hydrocarbon-like organic aerosol (HOA). Aerosols are less oxygenated than those observed in previous studies, with smaller concentrations of unsaturated groups, and do not fit H-NMR source apportionment fingerprints used for identification of secondary organic aerosol, marine organic aerosol, and biomass burning organic aerosol. It is recommended that a new fingerprint for highly urbanized locations be established utilizing these data and those from other large, polluted cities