Sampling and Analysis of Vapour-phase and Particulate-bound PAH from Vehicle Exhaust

Certain polycyclic aromatic hydrocarbons (PAH) are carcinogenic and discussion will commence shortly in Europe on the development of an appropriate ambient air quality standard. With this proposed standard in mind, it is important to understand the contribution made by different emission sources to ambient PAH; this paper addresses only the contribution from automotive exhaust emissions. Methods for the sampling and analysis of particulate bound PAH from exhaust emissions, although not standardised, are well established. Vapour phase PAH however, are often neglected and need to be accurately quantified to assess the total contribution made by automotive sources to anthropogenic PAH emissions to the atmosphere.

This paper describes the development of a technique applicable to the simultaneous collection and measurement of both vapour phase and particulate bound PAH in exhaust emissions. The final method selection focused on a filter/adsorbent trap sampler. This sampler was evaluated for collection efficiency, adsorbent contamination and repeatability.