Determination of Volatile N-Nitrosamines in the Vapour Phase of the Smoke from Various Tobacco Products

Volatile N-nitrosamines were determined in the vapour phase of tobacco smoke after accumulation of Iarge vapour samples on to a cooled capillary GLC column. Detection was effected by computerized mass spectrometry and by a nitrogen-specific detector. Five different tobacco products were studied with mass spectrometry for the presence of eight individuaI nitrosamines. The result was negative thirty-nine times and positive only once. Initially, the detection Iimit for the individual nitrosamines was 2 ng per 20-55 mI vapour injection; during this study the effective detection limit was Iowered for some of the compounds by a further twofold to fivefold increase of the vapour volume analysed. The one nitroso compound identified positively and unambiguously was N-nitrosopiperidine in the smoke from the American blend cigarettes. It amounted to about 5.6 ng in the vapour phase of the smoke of one cigarette. The partition of nitrosamines between vapour phase and particulate phase is not known, but amounts of more than 1 µg of dimethylnitrosamine or nitrosopiperidine in the whole smoke of one cigarette as found by some authors, seem improbably high. It is shown in this paper that exclusive use of the alkali flame ionization detector for nitrosamine determinations would have led to false-positive results, especially for dimethylnitrosamine.