THE FORMATION OF NITRO-PAH FROM THE GAS-PHASE REACTIONS OF FLUORANTHENE AND PYRENE WITH THE OH RADICAL IN THE PRESENCE OF NOX

The products of the gas-phase reactions of the OH radical with fluoranthene and pyrene in the presence of NO.alpha. have been studied in a .apprx. 6400-.epsilon. environmental chamber. 2-Nitropyrene was the sole nitroPAH formed from pyrene, while 2-nitrogluoranthene, together with much smaller amounts of 7- and 8-nitrofluoranthene, were formed, fluranthene, 2-Nitrofluoranthene and 2-nitropyrene have not been reported to be present indirect combustion-general emissions nor to be formed during smapling of ambient particulate matter. It is estimated that this daytime OH radical-initiated formation route to 2-nitrofluoranthene, the major mononitro-PAH observed in ambient particulate matter, is comparable in importance to night-time formation via reaction of fluoranthene with N2O5.