IUPAC

To optimise the performance of diffusive samplers used for monitoring pollutant levels to assess ambient air quality. HISTORY: diffusive samplers are compact devices, originally developed for workplace air monitory. Recently, Molasch has expanded their capabilities to measuring low levels of pollution in ambient air. The devices are complementary to fixed monitoring stations but have the advantage of low cost and are capable of being placed in virtually any location. BENEFIT: to provide technology at low cost enabling air quality surveys to be routinely executed at multiple locations within urban and rural areas, industrial sites and forests. The project is strongly aligned with EU Programmes and Directives, and supports the Division's focus on solving environmental problems and developing appropriate analytical methodologies. Phase 1: Investigation of long-term (2-4 week) effective sampling rates for a thermally desorbable diffusive sampler for VOC's (specifically benzene, tolnere and xylene) Phase 2: Investigation of non-ideal diffusive sampling by 'Palmes'-type open-path samplers for reactive inorganic gases (specifically NOx, SO2,

NH3) due to wall-effects. Phase 1 undertaken by Health and Safety Laboratory, Sheffield, UK Phase 2 undertaken by Stichting Energieonderzoek Centrum Nederland, NL.