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 particles of sidestream smoke. In true ETS (i. e., not concentrated or fresh sidestream 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 systems 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 that phase distributions and dynamics determined using glass-fibre filters are due to sampling system artefacts. Glass-fibre filters collect virtually all nicotine (vapour- and particulate-phase) at relatively short sampling intervals (1-2 min). The percentage of total nicotine trapped on the filter decreases with increasing sampling time. Using such a system, only that amount of total nicotine which exceeds the adsorptive capacity of the filter will break through and be collected by the sorbent medium. Attributing ETS particulate-phase nicotine to the quantity collected on a glass-fibre filter leads to erroneous conclusions regarding vapour-particulate phase dynamics.