Particle size-dependent concentrations of polycyclic aromatic hydrocarbons
Particle size-dependent concentrations of polycyclic aromatic hydrocarbons
复制标题
多环芳烃的粒径依赖性浓度
作者：
J. Schnelle;K. Wolf;G. Frank;B. Hietel;I. Gebefügi;A. Kettrup
测量了室外空气采样中多环芳烃的粒径依赖浓度。1994年10月，在慕尼黑郊区收集了大小分离的样品。使用了一个五级高容量级联冲击采样器（HVS，粒径DP < 10 µm，810 l min-1）和两个Berner型低压级联冲击采样器（LPI，79 l min-1，六级，DP= 0.04-21 µm和29 l min-1，九级，DP= 0.06-16 µm）。采用高效液相色谱荧光检测器定量测定了11种多环芳烃。采用质子激发X射线荧光分析法测定了铅、溴、锌、硫和铁的含量。用微分迁移率分析仪（DMA）测量DP= 0.01-1 µm范围内的颗粒数-浓度。颗粒物中的多环芳烃的浓度范围为0.8-3.8纳克m-3。在LPI样本中发现的浓度始终高于使用HVS采集的样本中的浓度。差异范围为30- 63%。两种LPI的结果非常一致。所有三个采样器的尺寸依赖性PAH浓度相似。使用HVS，在备用过滤器上发现了约60%的多环芳烃（DP < 0.66 µm）。在LPI样品中，总PAHs的40%存在于DP= 0.13-0.50 µm的颗粒上。铅、溴、锌和硫的分布与多环芳烃相同，而铁在DP= 2-4 µm时浓度最高。DMA测量得到单峰分布，DP= 0.22-0.28 µm处颗粒质量最大。
Particle size-dependent concentrations of PAHs from outdoor air sampling were measured. Size-segregated samples were collected at the outskirts of Munich in October 1994. A five-stage high-volume cascade impactor (HVS, particle diameter DP < 10 µm, 810 l min–1) and two Berner-type low-pressure cascade impactors (LPI, 79 l min–1, six-stage, DP= 0.04–21 µm and 29 l min–1, nine-stage, DP= 0.06–16 µm) were used. Eleven PAHs were quantified by HPLC with fluorescence detection. The concentrations of lead, bromine, zinc, sulfur and iron were measured by PIXE analysis. Particle number-concentrations in the range DP= 0.01–1 µm were measured with a differential mobility analyser (DMA). The concentrations of the PAHs in particulate matter were in the range 0.8–3.8 ng m–3. The concentrations found in the LPI samples always were higher than those in the samples taken with the HVS. The differences were in the range 30–63%. The results for the two LPI were in good agreement. The size-dependent PAH concentrations were similar with all three samplers. With the HVS, about 60% of the PAHs were found on the back-up filter (DP < 0.66 µm). In the LPI samples 40% of the total PAHs were found on particles with DP= 0.13–0.50 µm. Lead, bromine, zinc and sulfur showed the same distribution as the PAHs whereas iron had its maximum concentration at DP= 2–4 µm. The measurements with the DMA gave unimodal distributions with the maximum in particle mass at DP= 0.22–0.28 µm.