Capturing and Identification of Reactive Species in Secondary Organic Aerosol Atmosphere Originated from the Reaction of α-Pinene and Ozone by Using Radical Scavenging Reagents

Abstract

In order to clarify the mechanism to induce biologically hazardous phenomena in the environment by the reaction of the Secondary Organic Aerosol (SOA) and to identify reactive species in SOA atmosphere (particles and gaseous constituents are coexisting), experiments of capturing reactive species in the gas chamber where SOAs were generated via the reaction of ambient air containing α-pinene with ozone have been carried out by taking advantage of radical scavenging reagents. The obtained adducts in SOA atmosphere were analyzed by ESR (Electron Spin Resonance) and LC/MS (Liquid Chromatography/Mass Spectrometry). ESR signal intensities of the radical scavenging samples exposed by SOA atmosphere were smaller than those of the control sample due to the formation of diamagnetic adducts. And new peculiar peaks (α-pinene radical adducts produced by the trapping reactions with radical scavenging reagents) were detected by LC/MS. Thus, it is plausible that reactive species in ambient air can be identified surely from analytical approach of the adducts formed with radical scavenging reagents.