Particles in the atmosphere can influence visibility, negatively impact human health, and affect climate. One potential particle source, based on previous studies in this laboratory, is the reaction of methanesulfonic acid (MSA) with amines in the presence of water vapor.  However, organics are ubiquitous in the atmosphere, and could be involved in the initial stages of particle formation by enhancing or inhibiting nucleation  in addition to contributing to their growth.  Experiments to measure the effect of a series of organics of varying structure on particle formation and growth from MSA, amines, and water were performed in a custom-built small volume aerosol flow tube reactor. Analytical instruments and techniques include a particle size magnifier and scanning mobility particle sizer to measure particles, sampling onto a weak cation exchange resin with analysis by ion chromatography to measure amine concentrations, and filter collection and analysis by electrospray ionization mass spectrometry to measure MSA concentrations. Organics were measured by atmospheric pressure chemical ionization tandem mass spectrometry.  The impact of these organics on the initial particle formation as well as growth will be reported.  Theoretical calculations are used to shed light on the interactions of the precursors and small clusters with the organic.  Preliminary results suggest that organics are involved in the formation of small clusters and may enhance new particle formationNPF under certain conditions. The outcome of this work is an improved understanding of the fundamental chemistry of nucleation and growth to ultimately be incorporated into climate models to better predict how particles affect the global climate budget.

Exploring the effect of organics on new particle formation and growth from methanesulfonic acid, amines, and water

251st National Meeting (2016)

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