No abstract

Various factors which might contribute to the presence of or reflect on the formation of N'-nitrosonornicotine (NNN) or related nitrosamines in tobacco were studied. Using high-performance liquid chromatography (HPLC), the E- and Z-isomers of NNN were clearly separated and the rates of interconversion were determined. The E/Z ratio in tobacco approximated that observed in solution at similar pH and temperature. The influence of curing and stalk position on NNN levels in tobacco was determined. NNN was not detected in green tobacco but was detected in air-cured leaves from the same crop. No significant correlation was observed among stalk position and NNN levels in one variety of bright tobacco. Since NNN may derive from nicotine, two new nitrosamines, a nitrosamino ketone and a nitrosamino aldehyde, which could theoretically arise from nicotine, were synthesized. Analysis of tobacco for these components is currently in progress

To evaluate risk factors and to approach methods of reduction of the carcinogenic potential of cigarette smoke, the transfer rate of N-nitrosonornicotine in a popular U.S. blended cigarette into mainstream smoke was quantitatively determined. The mean transfer rate was 11.3%; thus approximately 46% of the tobacco-specific carcinogen in the smoke came from the tobacco, and the remainder was synthesized during smoking.

No abstract

No abstract