Chemical studies on tobacco smoke LXVIII. Analysis of volatile and tobacco-specific nitrosamines in tobacco products.

The yields of volatile N-nitrosamines in cigarette smoke are primarily dependent upon the nitrate content of the tobacco and, to some extent, on the protein content. Cellulose acetate tips, such as those found on most commercial filter cigarettes, selectively remove at least 70% of the volatile N-nitrosamines, independently of the pH of the weakly acidic or weakly alkaline smoke. So far, three tobacco-specific N-nitrosamines have been detected in tobacco and tobacco smoke. During tobacco processing and smoking, N'-nitrosonornicotine is formed by nitrosation of nicotine and, to a minor degree, by nitrosation of nornicotine, whereas 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone originates from oxidative nitrosation of nicotine. N'-Nitrosoanatabine is formed by nitrosation of the second most abundant tobacco alkaloid, anatabine. The tobacco-specific N-nitrosamines in the smoke arise partly from the tobacco by transfer and partly by nitrosation of the alkaloids during smoking (pyrosynthesis). Preliminary results indicate that cellulose acetate filter tips may selectively remove considerable amounts of the nonvolatile nitrosamines from the smoke.