Dicarbonyl products of the OH radical-initiated reaction of a series of aromatic hydrocarbons.
Aromatic hydrocarbons are important constituents of vehicle exhaust and of nonmethane organic compounds in ambient urban air. We used a derivatization technique with methane positive chemical ionization gas chromatography/mass spectrometry to investigate the carbonyl products formed from the OH radical-initiated reactions of toluene, the xylenes, and the trimethylbenzenes. Characteristic diderivatized molecular ions of dicarbonyl products were obtained. Consistent with previous studies, the 1,2-dicarbonyls glyoxal, methylglyoxal, and biacetyl were observed, as were all but one of the possible unsaturated 1,4-dicarbonyl coproducts. Unsaturated 1,4-diketones had formation yields similar to their potential coproduct 1,2-dicarbonyls. However, apart from HC(O)CH=CHCHO, unsaturated 1,4-dialdehydes and keto-aldehydes were generally observed in lower yield than their potential 1,2-dicarbonyl coproducts.
Arey
Janet
J
Air Pollution Research Center University of California Riverside, California 92521, USA. janet.arey@ucr.edu
Obermeyer
Genevieve
G
Aschmann
Sara M
SM
Chattopadhyay
Sulekha
S
Cusick
Roland D
RD
Atkinson
Roger
R
D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*
D006841:Hydrocarbons, Aromatic; D007659:Ketones; D017665:Hydroxyl Radical