Investigating the composition of organic aerosol resulting from cyclohexene ozonolysis:low molecular weight and heterogeneous reaction products

[摘要] The composition of organic aerosol formed from the gas phase ozonolysis ofcyclohexene has been investigated in a smog chamber experiment.Comprehensive gas chromatography with time of flight mass spectrometricdetection was used to determine that dicarboxylic acids and correspondingcyclic anhydrides dominated the small gas phase reaction products found inaerosol sampled during the first hour after initial aerosol formation.Structural analysis of larger more polar molecules was performed usingliquid chromatography with ion trap tandem mass spectrometry. This indicatedthat the majority of identified organic mass was in dimer form, built upfrom combinations of the most abundant small acid molecules, with frequentindication of the inclusion of adipic acid. Trimers and tetramerspotentially formed via similar acid combinations were also observed in lowerabundances. Tandem mass spectral data indicated dimers with either acidanhydride or ester functionalities as the linkage between monomers.High-resolution mass spectrometry identified the molecular formulae of themost abundant dimer species to be C₁₀H₁₆O₆,C₁₁H₁₈O₆, C₁₀H₁₄O₈ and C₁₁H₁₆O₈and could be used in some cases to reduce uncertainty in exact chemicalstructure determination by tandem MS.

[学科分类] 大气科学