Fig. 5
Surface pressure vs. surface area isotherms of Infasurf® before and after exposure to the most abundant components in smoke from 1R6F cigarettes, (a) nicotine, (b) acetaldehyde, (c) isoprene, and (d) tar. The amount of each component is equal to the amount in one complete cigarette according to the certificate of analysis of 1R6F cigarettes: 721 μg for nicotine, 522 μg for acetaldehyde, and 320 μg for isoprene, while the experiment with tar was performed with the particulate matter gathered on glass fiber filters from one complete cigarette. Significant increase in surface pressure compared to control (using a p-value of 0.05) is shown by *