The migration during storage, transfer to smoke, and filtration efficiency of nicotine, glycerin, and propylene glycol in cigarettes.
This study evaluated the migration during storage, transfer to smoke and filtration of nicotine, glycerin and propylene glycol (PG) for cigarettes with cellulose acetate/triacetin filters. Filtration efficiency (FE) and smoke yields were studied for two different types of experiments: 1) cigarettes with their original filters and 2) cigarettes with fresh filters inserted just prior to machine smoking. The behavior of PG was found to be much different than that of nicotine or glycerin presumably due a higher vapor pressure (which is about 2 times that of menthol). The migration of PG from the tobacco section to the filter increased linearly with time going from 15% (of total PG) at 76 days to 21% at 134 days for the whole filter and from 3.7% to 6.3% for the 10 mm mouth end of the filter. For nicotine and glycerin there was also some migration to the filter but it was less than 0.4% of that on the tobacco after 134 days. Nicotine showed a slightly greater FE than glycerin, but these two compounds behaved very similarly. PG filtration efficiency on fresh filters was about twice that of nicotine and glycerin. This indicates that another, equally important, mechanism must be taking place other than particulate filtration. Possibilities include direct vapor absorption or a vapor transport mechanism from the particulate to the filter fibers. This could also be taking place with the nicotine and glycerin but to a much smaller extent.