Author(s)

K. D. Stewart & J. M. Andino

Abstract

Understanding the heterogeneous (gas-particle) interactions that occur in the troposphere is of seminal importance for modellers that assess the atmospheric fates and transport of gases. One means of understanding these interactions is to calculate the mass uptake coefficient of a gaseous species onto common anthropogenic aerosols via an experimental means. The effective uptake behavior of gaseous Ethyl –3-Ethoxy Propionate (E3EP) onto ammonium sulfate and ammonium nitrate aerosols of varying total surface areas was studied using a custom manufactured flow system. E3EP is an organic species that is commonly found in paint and paint products. Ammonium sulfate and ammonium nitrate aerosols were studied because of their abundance in the troposphere. Gas phase E3EP concentrations were obtained using a solid phase microextraction technique (SPME) coupled to a gas chromatograph with a flame ionization detector (GC-FID). Analyses of the ammonium sulfate and ammonium nitrate aerosols were carried out using a Scanning Mobility Particle Sizing system (SMPS). As expected, losses of gaseous E3EP onto the aerosol surfaces decreased with decreasing initial surface area. The calculated initial effective uptake coefficients were shown to vary, depending on aerosol composition. Due to the lack of published literature data regarding the heterogeneous interactions of organic species in the troposphere, these studies provide a significant enhancement to the overall knowledge base. Keywords: aerosol, uptake, ethyl-3-ethoxypropionate, heterogeneous atmospheric chemistry.

Keywords

aerosol, uptake, ethyl-3-ethoxypropionate, heterogeneous atmospheric chemistry.