A124-04
Emissions of complex gas- and particle-phase organic mixtures emitted from oil sands operations and their detailed chemical speciation via offline analysis of airborne samples

Friday, 11 December 2020: 05:42
Virtual
Drew R Gentner1, Tori Hass-Mitchell2, Megan He3, Jenna Ditto4, Christina Chen3, Peeyush Khare1, Patrick Lee5, Amy Leithead6, Jeremy J B Wentzell7, Samar G Moussa6, Katherine Lynne Hayden6, Michael Wheeler6, Shao-Meng Li6 and John Liggio6, (1)Yale University, Department of Chemical and Environmental Engineering, New Haven, CT, United States, (2)Yale University, Department of Chemical & Environmental Engineering, New Haven, CT, United States, (3)Yale University, Chemical & Environmental Engineering, New Haven, CT, United States, (4)Yale University, Chemical and Environmental Engineering, New Haven, CT, United States, (5)Environment Canada Toronto, Toronto, Canada, (6)Environment and Climate Change Canada, Air Quality Research Division, Toronto, ON, Canada, (7)Environment Canada Toronto, Air Quality Processes Research Section, Toronto, ON, Canada
Recorded Presentation
Abstract:
Oil sands operations are reported to be a major regional source of secondary organic aerosol (SOA), similar in magnitude to that of major North American cities. To investigate real-world emissions of SOA precursors from oil sands operations, we chemically-speciated complex mixtures of gas- and aerosol-phase organic compounds collected during a 2018 Environment Canada flight campaign above the Athabasca oil sands region in Alberta, Canada. Gas-phase samples were collected on custom-made adsorbent tubes and analyzed via thermal desorption (Gertstel) with gas chromatography, atmospheric pressure chemical ionization, and high-resolution time-of-flight mass spectrometry (Agilent GC-Q-TOF). Aerosol-phase samples were collected on PTFE filters and analyzed via liquid chromatography with electrospray ionization and high-resolution tandem mass spectrometry (Agilent LC-Q-TOF). Both methods employ soft ionization to preserve the molecular ion and enable detailed characterization across a range of compound classes and volatilities, including aerosol functional group analysis via tandem MS (MS/MS). This represents the first airborne molecular-level characterization of complex mixtures of gas- and particle-phase organic compounds using offline sampling and high-resolution tandem MS with GC and LC. We observed substantial emissions of complex mixtures of volatile to extremely low-volatility organic compounds (VOCs-ELVOCs) from a diverse range of different facility types, including sulfur-, nitrogen-, and/or oxygen-containing functionalized compounds. Observed gas-phase emissions from oil sands operations are rich in SOA precursors in the intermediate-volatility and semivolatile (IVOC-SVOC) range, including substantial contributions of single-ring aromatics and polycyclic aromatic hydrocarbons (PAHs), explaining previously-observed SOA enhancements with downwind oxidation in past work.
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