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为了对柴油机排放PAHs在气相和颗粒相中的分配进行研究,采用了滤膜串联“PUF/XAD-2/PUF”吸附柱的方法采集柴油机排气中的气相和颗粒相PAHs,使用程序升温挥发(PTV)技术结合气相色谱-质谱联用(GC-MS)方法对PAHs进行了定性和定量分析。所用分析方法重复性的相对标准偏差(RSD)低于6.1%,检出限范围为0.016～0.375 ng/mL;滤膜的回收率为86.41%～118.35%,吸附柱回收率为71.83%～118.6%。结果表明:柴油机排放PAHs挥发性最强的二环主要存在于气相中,五环和六环PAHs主要存在于颗粒上,而三环和四环PAHs则在两相中平均分布。综合考虑吸附和吸收两种机理能更好地解释柴油机排放PAHs在两相中的分配行为。
In order to study the distribution of diesel exhaust PAHs in the gas phase and the particulate phase, the gas phase and the particulate phase PAHs in the exhaust of the diesel engine were collected by using the “PUF / XAD-2 / PUF” PAHs were qualitatively and quantitatively analyzed by temperature volatilization (PTV) combined with gas chromatography-mass spectrometry (GC-MS). The relative standard deviations (RSDs) of repeatability of the analytical methods used were less than 6.1%, and the detection limits were in the range of 0.016 ~ 0.375 ng / mL. The recovery rates of the filters were 86.41% ~ 118.35% and the recoveries of adsorption columns were 71.83% ~ 118.6 %. The results showed that the most volatile bicyclic PAHs emitted by diesel engines were mainly in the gas phase. The pentacyclic and hexahydric PAHs were mainly present on the particles, while the tricyclic and tetracyclic PAHs were evenly distributed in the two phases. Considering both adsorption and absorption mechanisms, the distribution of PAHs in diesel fuel can be better explained.