Investigating the composition of organic aerosol resulting from cyclohexene ozonolysis: low molecular weight and heterogeneous reaction products J. F. Hamilton1, A. C. Lewis1, J. C. Reynolds1, L. J. Carpenter1, and A. Lubben2 1Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK 2Bruker Daltonics, Banner Lane, Coventry , CV4 9GH, UK
Abstract. The composition of organic aerosol formed from the gas phase ozonolysis of
cyclohexene has been investigated in a smog chamber experiment.
Comprehensive gas chromatography with time of flight mass spectrometric
detection was used to determine that dicarboxylic acids and corresponding
cyclic anhydrides dominated the small gas phase reaction products found in
aerosol sampled during the first hour after initial aerosol formation.
Structural analysis of larger more polar molecules was performed using
liquid chromatography with ion trap tandem mass spectrometry. This indicated
that the majority of identified organic mass was in dimer form, built up
from combinations of the most abundant small acid molecules, with frequent
indication of the inclusion of adipic acid. Trimers and tetramers
potentially formed via similar acid combinations were also observed in lower
abundances. Tandem mass spectral data indicated dimers with either acid
anhydride or ester functionalities as the linkage between monomers.
High-resolution mass spectrometry identified the molecular formulae of the
most abundant dimer species to be C10H16O6,
C11H18O6, C10H14O8 and C11H16O8
and could be used in some cases to reduce uncertainty in exact chemical
structure determination by tandem MS.
Citation: Hamilton, J. F., Lewis, A. C., Reynolds, J. C., Carpenter, L. J., and Lubben, A.: Investigating the composition of organic aerosol resulting from cyclohexene ozonolysis: low molecular weight and heterogeneous reaction products, Atmos. Chem. Phys., 6, 4973-4984, doi:10.5194/acp-6-4973-2006, 2006.