Using a Vaporization Inlet for Aerosols Coupled with a Vocus Mass Spectrometer to Better Characterize Gas- and Particle-Phase Atmospheric Chemistry

Mitchell Alton, Philip Croteau, Andrew Lambe, Chase Glenn, Anita Avery, Leah Williams, MANJULA CANAGARATNA, Aerodyne Research, Inc.

     Abstract Number: 456
     Working Group: Exhibitor and Instrument Application Showcase

Abstract
Understanding the chemical composition of both atmospheric particles and the surrounding gas-phase is crucial for constraining how different compounds contribute to total atmospheric aerosol growth and chemistry. However, single-instrument measurements, mainly with the Filter Inlet for Gases and Aerosols (FIGAERO), are generally limited by time resolution of approximately an hour to heat and cool the collected sample. In this demonstration, we will show how to switch between particle- and gas-phase measurements using a Vaporization Inlet for Aerosols (VIA) at a user defined interval, not limited to filter collection times. The VIA will be coupled to a Vocus chemical ionization mass spectrometer and sample a stable aerosol source, switching between the gas- and particle-phases in real time. We will demonstrate how to take representative zeros, handle valve switching with minimal disruption to the measurements, and how changes in the operating conditions of the VIA change the observed signals. We will also discuss the optimal flow rates and residence times in the VIA for minimal thermal decomposition but maximum signals in the mass spectrometer.