| Title: | Emerging investigator series: chemical and physical properties of organic mixtures on indoor surfaces during HOMEChem |
| Author(s): | O'Brien RE; Li Y; Kiland KJ; Katz EF; Or VW; Legaard E; Walhout EQ; Thrasher C; Grassian VH; DeCarlo PF; Bertram AK; Shiraiwa M; |
| Address: | "Department of Chemistry, William & Mary, Williamsburg, VA 23185, USA. reobrien@wm.edu. Department of Chemistry, University of California Irvine, Irvine, CA 92697, USA. Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada. Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA. Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, USA. Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, USA and Scripps Institution of Oceanography and Department of Nanoengineering, University of California San Diego, La Jolla, California 92093, USA. Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA" |
| Journal Title: | Environ Sci Process Impacts |
| ISSN/ISBN: | 2050-7895 (Electronic) 2050-7887 (Linking) |
| Abstract: | "Organic films on indoor surfaces serve as a medium for reactions and for partitioning of semi-volatile organic compounds and thus play an important role in indoor chemistry. However, the chemical and physical properties of these films are poorly characterized. Here, we investigate the chemical composition of an organic film collected during the HOMEChem campaign, over three cumulative weeks in the kitchen, using both Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) and offline Aerosol Mass Spectrometry (AMS). We also characterize the viscosity of this film using a model based on molecular formulas as well as poke-flow measurements. We find that the film contains organic material similar to cooking organic aerosol (COA) measured during the campaign using on-line AMS. However, the average molecular formula observed using FT-ICR MS is approximately C50H90O11, which is larger and more oxidized than fresh COA. Solvent extracted film material is a low viscous semisolid, with a measured viscosity <104 Pa s. This is much lower than the viscosity model predicts, which is parametrized with atmospherically relevant organic molecules, but sensitivity tests demonstrate that including unsaturation can explain the differences. The presence of unsaturation is supported by reactions of film material with ozone. In contrast to the solvent extract, manually removed material appears to be highly viscous, highlighting the need for continued work understanding both viscosity measurements as well as parameterizations for modeled viscosity of indoor organic films" |
| Keywords: | Aerosols Cooking *Ozone Viscosity *Volatile Organic Compounds/analysis; |
| Notes: | "MedlineO'Brien, Rachel E Li, Ying Kiland, Kristian J Katz, Erin F Or, Victor W Legaard, Emily Walhout, Emma Q Thrasher, Corey Grassian, Vicki H DeCarlo, Peter F Bertram, Allan K Shiraiwa, Manabu eng England 2021/04/20 Environ Sci Process Impacts. 2021 Apr 28; 23(4):559-568. doi: 10.1039/d1em00060h" |
