title: Impact of the hydrocarbon to NOx ratio on secondary organic aerosol formation.
abstract: A series of m-xylene/NOx experiments were conducted in the new Bourns College of Engineering-Center for Environmental Research and Technology dual 90 m3 indoor smog chamber to elucidate the role of NOx on the secondary organic aerosol (SOA) formation potential of m-xylene. The results presented herein demonstrate a clear dependence of m-xylene SOA formation potential on NOx, particularly at atmospherically relevant organic aerosol concentration. Experiments with lower NOx levels generated considerably more organic aerosol mass than did experiments with higher NOx levels when reacted m-xylene was held constant. For example, SOA formation from approximately 150 microg m(-3) reacted m-xylene produced 0.6-9.3 microg m(-3) aerosol mass for NOx concentrations ranging from 286 to 10 ppb. The increase in SOA formation was not attributable to changes in ozone and nitrate concentration. A general discussion about possible influences of NOx on SOA formation for this system is included.
authors.affiliation: Bourns College of Engineering--Center for Environmental Research and Technology, and Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Song
authors.forename: Kwangsam
authors.initials: K
authors.lastname: Na
authors.forename: David R
authors.initials: DR
authors.lastname: Cocker
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis*; D008962:Models, Theoretical; D009589:Nitrogen Oxides / Q000032:analysis* / Q000737:chemistry*; D014992:Xylenes / Q000737:chemistry*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D009589:Nitrogen Oxides; D014992:Xylenes