A204-02
Indoor source characterization and quantification of cooking organic aerosol contributes to more accurate ambient source apportionment with aerosol mass spectrometers

Tuesday, 15 December 2020: 19:08
Virtual
Erin Katz1,2, Hongyu Guo3, Pedro Campuzano-Jost3, Doug A Day3, Wyatt Brown3, Erin Boedicker4, Matson A Pothier5, David M. Lunderberg6, Kanan Patel7, Sameer Patel8, Lea Hildebrandt Ruiz7, Marina Vance8, Delphine Farmer5, Allen H Goldstein2, Jose L Jimenez3 and Peter DeCarlo9, (1)Drexel University, Philadelphia, PA, United States, (2)University of California Berkeley, Berkeley, CA, United States, (3)University of Colorado at Boulder, Cooperative Institute for Research in Environmental Sciences (CIRES) and Department of Chemistry, Boulder, CO, United States, (4)Colorado State University, Chemistry, Fort Collins, CO, United States, (5)Department of Chemistry, Colorado State University, Fort Collins, CO, United States, (6)UC Berkeley, Berkeley, United States, (7)University of Texas at Austin, McKetta Department of Chemical Engineering, Austin, TX, United States, (8)University of Colorado, Boulder, CO, United States, (9)Johns Hopkins University, Department of Environmental Health and Engineering, Balitmore, MD, United States
Recorded Presentation
Abstract:
Cooking is a prominent source of organic aerosols (OA) in indoor and outdoor urban environments, and the Aerodyne aerosol mass spectrometer (AMS) is widely used for quantitative OA characterization. Positive matrix factorization (PMF) of AMS data provides consistent discrete factors that can be connected to OA sources. PMF-derived cooking OA (COA) has been identified in outdoor studies, however, COA has been difficult to separate and fully attribute to cooking due to its spectral similarity to other primary OA (POA).

AMS data was analyzed for two indoor campaigns, HOMEChem and ATHLETIC. During ATHLETIC, outdoor generated COA was introduced indoors via the building ventilation system. During HOMEChem, deliberate cooking experiments were performed. Four factors associated with cooking were identified with PMF of HOMEChem AMS data. The factors were attributable to burning/browning and caramelization processes, cooking oils, and potentially lubricants inside small appliances. The mass spectra of the factors correlate with typical outdoor derived factors: biomass burning OA, COA identified in prior ambient campaigns, and hydrocarbon-like OA associated with vehicle emissions. These PMF factors contribute to a better understanding of outdoor POA attribution.

Additionally, comparison between AMSs and co-located instruments during COA-dominated sampling periods suggested a discrepancy in mass concentration during both campaigns when ambient quantification parameters were applied to AMS data. Evaluation of factors contributing to the discrepancy combined with laboratory studies indicated the relative ionization efficiency (RIE) applied to AMS OA during cooking-dominated times required adjustment. RIECOA during HOMEChem and ATHLETIC ranged from 4.02 to 5.66, a substantial increase from the value of 1.4 applied to ambient OA, consistent with prior laboratory work. The applicability of a higher RIEPOA is evaluated for prior ambient studies, as well.

<< Previous Abstract | Next Abstract >>