Chemical Studies on Tobacco Smoke: LI: Studies on Non-Volatile Nitrosamines in Tobacco

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