Characterization of PM2.5-bound nitrated and oxygenated PAHs in two industrial sites of South China

Daytime and nighttime PM2.5 samples were collected between August 5 and 16, 2009 and between January 24 and February 4, 2010 in an industrial complex site (site A) and an e-waste recycling site (site B) to determine the seasonal and diurnal variations of nitrated (nitro-) and oxygenated (oxy-) polycyclic aromatic hydrocarbons (PAHs) with gas chromatography/mass spectrometry (GC/MS). The two sites show similar composition for nitro- and oxy-PAHs although the composition of parent PAHs was quite different. 3 + 2-Nitrofluoranthene (3 + 2NFL) was the most abundant nitro-PAH, while 9,10-anthraquinone (Anquin), benzanthrone (Bzone) and 6H-benzo[cd]pyrene-6-one (Bpone) were the three major oxy-PAHs species. The concentrations of Σnitro-PAHs and Σoxy-PAHs were about 2–3 orders of magnitude lower than those of Σparent PAHs. Most of the nitro- and oxy-PAHs show notable seasonal variation. 7-Nitrobenz[a]anthracene (7NBaA), Bzone and benzo[a]anthrancene-7,12-dione (Bzdion) demonstrated a pronounced diurnal variation. The occurrence of nitro- and oxy-PAHs in the two sites can be accounted by direct emission and atmospheric secondary formation.