Real time sampler, RAMS, for the determination of PM(2.5), including semi-volatile species

摘要

Fine particles in urban environments contain substantial quantities of material which can be lost from the particles during sample collection on a filter. These include ammonium nitrate and semi-volatile organic compounds. Methods for the accurate collection of these species in integrated samples have been developed using diffusion denuder samplers. It is often desirable to determine fine particulate material on a real-time basis. Instruments such as the TEOM monitor are available for this purpose. However, these real-time instruments suffer from inaccuracies in the determination of semi-volatile particulate species. Methods for the accurate determination of these semi-volatile fine particulate species and the determination of fine particulate matter on a real-time basis is essential for a complete understanding of the possible causes of health effects associated with exposure of fine particles. RAMS (real-time ambient mass sampler, has been developed for accurate continuous monitoring of fine particulate mass, including semi-volatile species. RAMS combines diffusion denuder and TEOM technologies. Comparisons of real-time measurements with the modified system, measurements with a conventional TEOM monitor and integrated measurements using diffusion denuders are reported. The results show that semi-volatile fine particulate species can be continuously and accurately monitored with the RAMS.