The fate of ingredients in and impact on cigarette smoke.

A series of experiments are described, undertaken on both volatile and non-volatile ingredients either during cigarette smoking or under pyrolysis conditions that try to simulate cigarette smoking. In particular, the fate of a series of deuterium and (13)C labelled volatiles was studied which demonstrated that, in a similar way to unlabelled volatiles, a large proportion of each was transferred intact into mainstream smoke. The unaccounted material, which was not transferred intact, in the studies of both volatile and non-volatile ingredients was primarily transformed into products of complete combustion such as carbon monoxide or carbon dioxide with only very minor amounts transformed into products of incomplete combustion. In addition, the studies on both unlabelled and deuterium labelled compounds demonstrated that the utility of pyrolysis studies lies mainly in distinguishing between those compounds that transfer intact into mainstream smoke from those that might be liable to degrade. Pyrolysis does not provide a robust prediction of the compounds that are formed from ingredients during cigarette smoking studies.