Abstract
For the estimation of the different methods used for obtaining and fractioning tobacco tars, it is necessary to consider the reactivity of the For the estimation of the different methods used for obtaining and fractioning tobacco tars, it is necessary to consider the reactivity of the individual components and the characteristic action of the entire product. For analytical and biological tests a product is required which has not undergone any important chemical or biochemical changes. It is shown that this important condition has mostly been neglected. The changes likely to occur in the tar during the different smoking and preparation procedures are discussed. It is pointed out that a great number of compounds have been described, in particular in the more recent literature, which are eager to react with other substances and which, being constituents of tobacco smoke, might be responsible for such chemical changes.Several tars were submitted to a limited ageing under different physical conditions. Such simple tests demonstrate the important changes taking place in the original tar when submitted to temperature, light and air and if concentrations in the solvent are too high. On the basis of such general reflections it is concluded that the biological tests described until now require reexamination and that it is necessary to develop and apply such procedures, both for the production and the preparation of tobacco tars, which prevent the formation of artefacts