Abstract View
Aerosol Composition Measurements Using the Vocus Inlet for Aerosol (VIA): Applications in an Oil and Gas Production Region and an Indoor Cooking Event
DANIEL C. BLOMDAHL, Leif Jahn, Nirvan Bhattacharyya, Catherine Masoud, Kristi McPherson, Pearl Abue, Kanan Patel, Jordan Krechmer, Lea Hildebrandt Ruiz, Pawel K. Misztal, University of Texas at Austin
Abstract Number: 666
Working Group: Aerosol Chemistry
Abstract
The Vocus Inlet for Aerosol (VIA; Aerodyne, Inc.) is a novel attachment to the Vocus PTR-ToF mass spectrometer to characterize the chemical composition of aerosols at high time resolution (1 Hz). The VIA thermally denudes particles into gas-phase compounds that the Vocus PTR-ToF then detects downstream. A honeycomb activated-carbon denuder removes gas-phase compounds upstream of the thermal denuder to ensure mass spectrum signals are solely from aerosol decomposition. The capabilities of the VIA will be discussed using laboratory results and results from two measurement occasions: (a) ambient aerosols from an active oil and gas extraction region and (b) an indoor oil cooking event. The VIA and Vocus PTR-ToF was used in a field campaign near Karnes City, a small town in south-central Texas surrounded by active oil and gas infrastructure. Temperature ramps of the VIA thermal denuder were completed in the field from 160 °C to 260 °C over 4 hours of measurements to elucidate the dependence of temperature on the desorption efficiency of compounds with semi- or low volatility. Real-time (1 Hz time resolution) measurements of aerosol composition with the VIA thermal denuder set at constant temperature over 5 days will also be reported. The chemical concentration data from an indoor cooking event involving olive, avocado, and canola oils—among other foods—will also be reported. Results from the ambient aerosol data from Karnes City and the rapid production of aerosols from cooking oils will showcase the wide range of applications of the VIA-Vocus system.