MS gas-phase cigarette solutions were prepared in the same manner as whole MS solutions except that a Cambridge filter (University of Kentucky, Lexington, KY) was interposed between the puffer box and the collection flask. This filter was replaced with a fresh filter after 30 puffs had been generated. To prepare the MS particulate-phase cigarette solutions, each filter used during collection of the MS gas phase was cut into 1 X 2-cm pieces. These pieces were put into a 10-ml glass tube containing 5 ml of collection medium and vortexed for 30 sec to facilitate the extraction of water-soluble components. The filter pieces and extract were then placed on a glass-packed funnel and a vacuum was applied until the filter appeared dry. The two filter extracts were combined and used as the MS particulate-phase solution. ventolin inhaler
Wiole SS cigarette smoke solutions were prepared using the same procedure except that the smoke from the burning tip of a cigarette was collected within a 2.5-cm-diameter glass cylinder. The smoke was delivered continuously via peristaltic pump to the collection medium until 30 puffs of MS smoke had been produced. SS gas-phase cigarette solutions were generated by placing a Cambridge filter between the burning cigarette tip and the collection medium. This filter was replaced with a fresh filter after 15 puffs had been generated. To make the SS particulate solutions, these filters were extracted as described for the MS partic-ulate-phase solutions. After preparation, all cigarette smoke solutions were placed on ice and assayed within 1 h of collection.