[Examinations of the possibilities to nitrosate nicotine and nornicotine and of the formation of N-nitrosonornicotine in the stomach of smokers (author's transl)]

Abstract

It was examined how easily the tobacco-smoke constituents, nornicotine, and nicotine, are nitrosated in an acidic aqueous medium, and if a formation of nitrosamines in the stomach of smokers is possible after swallowing amine-containing saliva. More than 10% of the nornicotine present in tobacco-smoke is dissolved in saliva during smoking. While from the tertiary amine, nicotine, only a small yield of N-nitrosonornicotine was obtained, from nornicotine an about 50 times higher yield of nitrosocompound was formed than from N-methylbenzylamine, a secondary amine of moderate basicity and hence of moderate reactivity toward the nitrosating agents. The amounts of nitrite in the neutral stomach contents varied between 15 and 250 ppm; in the acidic stomach contents no nitrite was detected. No increase was observed during cigarette smoking. In 61 gastric juice of volunteers who smoked a total number of 280 cigarettes no nitrosonornicotine and no nitrosopyrrolidine (pyrrolidine is present in tobacco-smoke in similar amounts as nornicotine) was detected (detection limit: 5 ppb).