AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Accelerated Reaction of Carbonyls in Aerosol Droplets Studied with Droplet Assisted Ionization
YAO ZHANG, Michael J. Apsokardu, Devan E. Kerecman, Murray Johnston, University of Delaware
Abstract Number: 141 Working Group: Aerosol Chemistry
Abstract Droplet assisted ionization (DAI) is a method developed in our laboratory for online analysis of aqueous droplets. This method is ideally suited for studying the kinetics of aerosol reactions. In the current work, we present a kinetic study of the reaction of Girard’s T reagent (GT) with carbonyls in α-Pinene Secondary Organic Aerosol (SOA). This reaction proceeds very slowly in bulk solution, but quickly in aerosol droplets. The time dependence of the reaction was varied by changing the tube length, and therefore the droplet transit time, between the atomizer where droplets are initially formed and the mass spectrometer where the molecular products and reactants in the droplets are detected. The reaction rate constant was determined from the time dependence of product and reactant signal intensities assuming pseudo-first order kinetics. The activation energy associated with reaction acceleration was determined from the dependence of product and reactant signal intensities on the temperature of the DAI inlet. The results give insight into the mechanism of enhanced reactivity in aerosol droplets.