[PAHs in foliar dust from Beijing urban area]

A five-step sequential elution procedure with or without supersonic effect was tested for extraction of foliar dust from leaves of Euonymus japonicus collected at two locations of Beijing urban area. The samples were collected from either roadside or campus far away from any motor traffic. The foliar dust was characterized for size distribution, organic carbon content, and PAHs content. It was found that majority of the foliar dust can be eluted in 4 min by distill water under supersonic effect at room temperature without shaking. The amount of foliar dust on the sample from roadside was almost twice as much as those from campus, while the particle size of the former was relatively large. Large amount of coarse particles came from disturbance of motor vehicles. Slightly high concentrations of PAH species were detected in the sample from campus compared to those in the samples collected from roadside.