Particle Formation and Gas/Particle Partition Measurements of the Products of the Naphthalene-OH Radical Reaction in a Smog Chamber

• Published in: Polycyclic aromatic compounds 2002-01, Vol.22 (3-4), p.729-736
• Main Authors: Mihele, Cristian M., Wiebe, H. Allan, Lane, Douglas A.
• Format: Article
• Language: English
• Subjects: Gas/particle Partition Ratio; Naphthalene; Radical Reactions; Smog Chamber
• ISSN: 1040-6638; 1563-5333
• DOI: 10.1080/10406630290103889

The formation of particles during the reaction of naphthalene with OH radicals in a smog chamber was followed by means of a scanning particle-sizing system and aerosol spectrometer probe. The initial formation of nucleation-sized particles (0.03-0.09 w m) quickly grew into an accumulation mode (0.1-3.0 w m) during the photolysis. A small nucleation mode component, however, persisted throughout the experiment, although the major portion of the mass is found in the accumulation mode at later stages in the reaction. Multichannel, annular, diffusion denuders have been used to determine the gas/particle partition factors for many of the observed products. While 1,4-naphthoquinone appears predominantly in the gas phase, the 1- and 2-naphthols and the nitronaphthalenes were found predominantly in the particle phase. Although 2-formylcinnamaldehyde, the most abundant product in the naphthalene-OH photolysis, was split approximately evenly between the gaseous and the particulate phases, the 2-formylcinnamic acid was found almost exclusively in the particle phase.