Determination of particle-associated polycyclic aromatic hydrocarbons in urban air of Beijing by GC/MS.

Particle-associated polycyclic aromatic hydrocarbons (PAHs) collected in urban air of Beijing were studied using a gas chromatograph mass spectrometer (GC/MS). The average concentration of particle-associated PAHs measured in this work was in the range from 28.53 to 362.15 ng/m3, which suggested a serious pollution level of PAHs in Beijing. The results also showed that the concentration of PAHs in the winter was distinctly higher than that in summer and spring. Benzo(a)pyrene (BaP) and benzo(a)pyrene-equivalent carcinogenic power (BaPE) were adopted to evaluate the PAHs pollution state at the sampling site. Through some diagnostic ratios, it can be concluded that traffic exhaust, especially vehicles with diesel engines, and domestic coal-burning heaters might have a prominent contribution to the PAHs concentration.