ARTIFACTS IN DETERMINING THE VAPOR-PARTICULATE PHASE DISTRIBUTION OF ENVIRONMENTAL TOBACCO-SMOKE NICOTINE

Nicotine in environmental tobacco smoke (ETS) resides predominantly in the aerosol vapour phase as a result of evaporation from the particle s of sidestream smoke. In true ETS (i. e., not concentrated or fresh s idestream smoke), the fraction of nicotine associated with the aerosol particulate phase is quite small, typically less than 5% of the total . Recently, some investigators have collected nicotine with sampling s ystems employing sorbent resin cartridges downstream from glass-fibre filters, and have attributed the nicotine retained on the glass-fibre filters to the particulate phase. The data reported here demonstrate t hat phase distributions and dynamics determined using glass-fibre filt ers are due to sampling system artefacts. Glass-fibre filters collect virtually all nicotine (vapour- and particulate-phase) at relatively s hort sampling intervals (1-2 min). The percentage of total nicotine tr apped on the filter decreases with increasing sampling time. Using suc h a system, only that amount of total nicotine which exceeds the adsor ptive capacity of the filter will break through and be collected by th e sorbent medium. Attributing ETS particulate-phase nicotine to the qu antity collected on a glass-fibre filter leads to erroneous conclusion s regarding vapour-particulate phase dynamics.