Efficient bulk mass accommodation of N2O5 into neutral aqueous aerosol
Goran Gržinić1,2, Thorsten Bartels-Rausch1, Andreas Türler2,3, and Markus Ammann21Laboratory of Environmental Chemistry, Paul Scherrer Institut, Villigen, 5232, Switzerland 2Department of Chemistry and Biochemistry, University of Bern, Bern, 3012, Switzerland 3Laboratory of Radiochemistry, Paul Scherrer Institut, Villigen, 5232, Switzerland
Received: 12 Dec 2016 – Accepted for review: 14 Dec 2016 – Discussion started: 14 Dec 2016
Abstract. An isotope exchange experiment with the short-lived radioactive tracer 13N is used to trace N2O5 uptake into nitrate containing aqueous aerosol particles. While uptake of 13N labelled N2O5 to deliquesced Na2SO4 aerosol is consistent with previous studies, in presence of aerosol phase nitrate efficient exchange of labeled nitrate with the non-labeled nitrate pool was observed. The experiments provide direct evidence for efficient bulk mass accommodation of N2O5 into aqueous solution with an accommodation coefficient >0.4 at room temperature, as well as for the fast disproportionation into nitronium and nitrate. While for experimental reasons this study is limited to non-acidic aerosol, it is likely that mass accommodation is not limiting N2O5 uptake also under wider ranges of conditions.
Gržinić, G., Bartels-Rausch, T., Türler, A., and Ammann, M.: Efficient bulk mass accommodation of N2O5 into neutral aqueous aerosol, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1118, in review, 2016.