城区叶面尘特性及其多环芳烃含量

用多步连续洗脱方法采集了干线道路路侧和远离道路校园内冬青卫矛叶面积尘,研究了叶面尘的采集方法.测定了2类叶面尘的粒径分布、有机碳含量和多环芳烃含量.结果表明,所测样品上的叶面尘可以在超声条件下4min一步洗脱.路边样品叶面尘积累量几乎是校园样品的2倍.2样品粒径分布基本形态非常相似,包括200μm以上和以下2个组分.后者占绝对优势.但校园内样品叶面尘粒径明显小于路边样品,两者粒径中位数分别为17.2μm和23.1μm.路边样中相对较粗部分显然来自机动车行驶扰动.由于颗粒较细,采自校园叶面尘中多环芳烃含量略高于路边样品.但不同多环芳烃分布谱非常相似.

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.