Variation of the gas phase composition within a burning cigarette
A technique for estimating the gas phase composition throughout a burning cigarette has been described. It was found that the gas mixture in the cone region contains relatively large amounts of reducing gases and little or no oxygen. This finding is compatible with the prediction that a reducing atmosphere exits in this region. The change in gas composition between the cone region and the exit smoke stream can be ascribed principally to dilution with air entering around the burning cone and through the paper wrapper, with a greater part of the diluting air coming through the paper. Secondary effects arising from diffusion of gases out of the cigarette and adsorption of gases on the tobacco mass and from low temperature production of carbon dioxide were also detected.