Real-time organic aerosol chemical speciation in the indoor environment using extractive electrospray ionization mass spectrometry |
| |
| Authors: | Wyatt L Brown Douglas A Day Harald Stark Demetrios Pagonis Jordan E Krechmer Xiaoxi Liu Derek J Price Erin F Katz Peter F DeCarlo Catherine G Masoud Dongyu S Wang Lea Hildebrandt Ruiz Caleb Arata David M Lunderberg Allen H Goldstein Delphine K Farmer Marina E Vance Jose L Jimenez |
| |
| Affiliation: | 1. Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, CO, USA;2. Aerodyne Research, Inc., Billerica, MA, USA;3. Department of Civil, Architectural, and Environmental Engineering, Drexel University, Philadelphia, PA, USA;4. McKetta Department of Chemical Engineering, University of Texas, Austin, TX, USA;5. Department of Chemistry, University of California, Berkeley, CA, USA;6. Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, USA;7. Department of Chemistry, Colorado State University, Fort Collins, CO, USA;8. Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA |
| |
| Abstract: | Understanding the sources and composition of organic aerosol (OA) in indoor environments requires rapid measurements, since many emissions and processes have short timescales. However, real-time molecular-level OA measurements have not been reported indoors. Here, we present quantitative measurements, at a time resolution of five seconds, of molecular ions corresponding to diverse aerosol-phase species, by applying extractive electrospray ionization mass spectrometry (EESI-MS) to indoor air analysis for the first time, as part of the highly instrumented HOMEChem field study. We demonstrate how the complex spectra of EESI-MS are screened in order to extract chemical information and investigate the possibility of interference from gas-phase semivolatile species. During experiments that simulated the Thanksgiving US holiday meal preparation, EESI-MS quantified multiple species, including fatty acids, carbohydrates, siloxanes, and phthalates. Intercomparisons with Aerosol Mass Spectrometer (AMS) and Scanning Mobility Particle Sizer suggest that EESI-MS quantified a large fraction of OA. Comparisons with FIGAERO-CIMS shows similar signal levels and good correlation, with a range of 100 for the relative sensitivities. Comparisons with SV-TAG for phthalates and with SV-TAG and AMS for total siloxanes also show strong correlation. EESI-MS observations can be used with gas-phase measurements to identify co-emitted gas- and aerosol-phase species, and this is demonstrated using complementary gas-phase PTR-MS observations. |
| |
| Keywords: | chemical composition cooking extractive electrospray ionization mass spectrometry (EESI-MS) field measurements organic aerosol residential environments |
|
|
