Per puff analysis of selective removal in ultra-slim filters
Understanding selective filtration is important for cigarette filter manufacturers to optimize cigarette filter performance to meet potential regulatory requirements. The analysis of selective filtration on a per puff basis provides insight into the changes in smoke chemistry and other factors which impact selective filtration mechanisms. Phenolic compounds are frequently used for selective filtration studies because these compounds are known to be selectively removed by cellulose acetate filters.
For this study, selective filtration of hydroquinone, phenol and other phenolic compounds were examined on a per puff basis for ultra slim and conventional filters. These compounds were determined by HPLC with fluorescence detection after extraction of Cambridge pads or filters in an alcohol solution. Direct analysis of extracts enables the phenolic compounds to be determined from the same smoking session as used to determine nicotine free dry particulate matter (NFDPM), nicotine, and CO.
The results showed increases in NFDPM delivery on the last whole puffs when the vents were closed relative to vents open for both conventional and ultra slim cigarettes. Ultra slim cigarettes had a much larger increase in NFDPM than conventional cigarettes when smoked to the nearest whole puff relative to the butt mark. Also, the delivery of phenol significantly decreased on the last puffs for both ultra slim and conventional cigarettes. The phenol delivery for the ultra slim cigarettes decreased on earlier puffs relative to conventional cigarettes. These results are important to cigarette filter manufacturers in understanding the smoke chemistry on a per puff basis for both ultra slim and conventional cigarettes and how the selective removal in the filter can change during smoking. It is also important to understand the impact of testing protocol on selective removal by a filter on a per puff basis.