Compariso of polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in airborne and automobile exhaust particulates

摘要

Polycyclic aromatic hydrocarbons(PAH)and nitropolycyclic aromatic hydrocarbons(NPAH)in airborne particulates collected simultaneously at downtown and suburban sites and in exhaust particulates form diesel and gasoline engine vehicles were determined. The mean concentrations of all compounds in the atmosphere were lower at the suburban site. The differences between the two sites wee smaller in airborne particulates than in the atmosphere. However, the difference in NPAH concentrations in particulates between the towo sites was greater than the difference in PAH concentratins, suggesting that the NPAH were less stable than the PAH. The concenctrations of 1-nitropyrene and 1,3-, 1,6- and 1,8- dinitropyrenes were tgenerally much higher in automobile exhaust particulates than in airborne particulates vbecause the former were collected directly. However, 2-nitrofluoranthene and 2-nitropyrene were observed in airborne particulates but not in automobile exhaust particulates. The diurnal concentrations showed that 2-nitrofluoranthene and 2-nitropyrene might be formed by a hydroxyl radical-initiated reaction followed by nitration.