Detection of radical species formed by the ozonolysis of α-pinene

• Published in: Journal of atmospheric chemistry Vol. 66; no. 3; pp. 137 - 155
• Main Authors: Pavlovic, Jelica, Hopke, Philip K.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2010; Springer
• Subjects: Atmospheric chemistry; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Chemical composition and interactions. Ionic interactions and processes; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Exact sciences and technology; External geophysics; Meteorology; Phosphonates; Troposphere; DMPO; Reactive oxygen species; Free radicals; Spin trapping; DEPMPO; Ozonolysis; volatile organic compounds; hydrocarbons; Reaction product; troposphere; Electrospray; Free radical; Biogenic factor; Atmospheric chemistry; Mass spectrometry MS/MS; Pinene; organic compounds
• ISSN: 0167-7764; 1573-0662
• DOI: 10.1007/s10874-011-9197-y

Highly reactive free radical species have been subject of many toxicological in vivo and in vitro studies because of the oxidative cell damage they cause. Similar species have been postulated to be the key intermediates formed during many environmental chamber reactions and atmospheric oxidation of organic species present in the troposphere. Thus, detection and characterization of these transient radical species are important steps in understanding the atmospheric chemistry and confirming the reaction pathways involved in secondary organic aerosol formation. Study of these species is particularly difficult because of their short life-times. To facilitate such studies, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and diethyl-(2-methyl-1-oxido-3,4-dihydro-2H-pyrrol-2-yl) phosphonate (DEPMPO) nitrone spin traps were used to capture radicals formed from the α-pinene/ozone reaction. Electrospray ionization/tandem mass spectrometry (ESI/MS n ) was applied to elucidate their structures. Characteristic fragments with m/z 114, m/z 130 and m/z 148 with the DMPO trap, and m/z 236, m/z 252, and m/z 270 with the DEPMPO trap indicated the existence of alkyl, alkoxyl and peroxyl radicals, respectively.