Composition Studies on Tobacco XXXVl: Changes in Smoke Composition and Filtration by Artificial Alteration of Smoke pH: Vapour Phase Constituents

The pH of smoke from U.S. commercial cigarettes was varied from 4.2 to 8.2 by the use of acidic and basic cigarette additives. Small reductions or insignificant differences were obtained in the levels of hydrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethane, ethylene and oxides of nitrogen in smoke of varying pH. Reductions of 79-91 % of hydrogen sulfide and more than 90 % of hydrogen cyanide in the vapour phase were obtained by changing the pH from 5.6 to 8.2 in nonfilter cigarettes. Using an activated carbon-cellulose acetate filter with the alkaline smoke, further reductions were obtained for these components. Samples of smoke from cigarettes containing alkaline or acidic additive show some slight reduction in formaldehyde, acetaldehyde, acrolein, acetone, acetonitrile and methanol but the reductions for some of these components may be insignificant.