Title: Real-time organic aerosol chemical speciation in the indoor environment using extractive electrospray ionization mass spectrometry.
Authors: Brown, Wyatt L; Day, Douglas A; Stark, Harald; Pagonis, Demetrios; Krechmer, Jordan E; Liu, Xiaoxi; Price, Derek J; Katz, Erin F; DeCarlo, Peter F; Masoud, Catherine G; Wang, Dongyu S; Hildebrandt Ruiz, Lea; Arata, Caleb; Lunderberg, David M; Goldstein, Allen H; Farmer, Delphine K; Vance, Marina E; Jimenez, Jose L
Published In Indoor Air, (2021 Jan)
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.
PubMed ID: 32696534
MeSH Terms: No MeSH terms associated with this publication