AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Molecular Composition and Gas-Particle Partitioning of Indoor Cooking Aerosol: Insights from a FIGAERO-CIMS
CATHERINE MASOUD, Dongyu S. Wang, Lea Hildebrandt Ruiz, University of Texas at Austin
Abstract Number: 276 Working Group: The Air We Breathe: Indoor Aerosol Sources and Chemistry
Abstract The average American spends most of their life indoors, highlighting the importance of studying indoor air pollutants. The House Observations of Microbial and Environmental Chemistry (HOMEChem) field campaign focused on the effects of cooking, cleaning, and occupancy-related activities in a home. Here, we present our analyses of the data collected during cooking events, which resulted in the highest observed organic aerosol concentrations. Using a Filter Inlet for Gases and Aerosols mounted onto a High-Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (FIGAERO-CIMS), we identify over 400 compounds using high-resolution peak fitting and propose their chemical identities and sources. We then categorize them under (1) cooking-related emissions (2) industrial emissions (phthalates, phosphanes, organosulfates, etc.), (3) personal care products, and (4) others. We also identify “chemical markers” for some of the cooking events – for example we observed elevated paradol levels (from ginger), and levoglucosan and isomaltol levels (from caramelization of sugar) when a sweet potato casserole was prepared.
We use the ratio of gas and particle-phase signals obtained from the FIGAERO-CIMS to calculate a partitioning fraction, and convert species-specific partitioning fractions to saturation concentration values. We compare these values to saturation concentration values obtained from parameterizations based on elemental composition (Li et al., 2016). We find that while there is substantial correlation between the calculated (via volatility parametrizations) and measured (using the FIGAERO-CIMS instrument) saturation concentrations, the volatility parameterization method consistently gives higher values than those obtained from the FIGAERO. We suggest potential reasons for this difference and compare different methods for obtaining volatility information from a FIGAERO-CIMS.
Li, Y., Pöschl, U., & Shiraiwa, M. (2016). Molecular corridors and parameterizations of volatility in the chemical evolution of organic aerosols, 3327–3344. https://doi.org/10.5194/acp-16-3327-2016