DISTRIBUTION OF TOBACCO CONSTITUENTS IN TOBACCO LEAF TISSUE .1. TOBACCO-SPECIFIC NITROSAMINES, NITRATE, NITRITE, AND ALKALOIDS

Leaves from a dark air-cured tobacco variety (Ky 171) were divided into 41 defined leaf segments. All samples were analyzed for nitrate nitrogen, nitrite nitrogen, nicotine, myosmine, nornicotine, anabasine, anatabine, N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Nitrite concentration was highest at the base of the leaf and decreased toward the tip of the leaf. Concentration of alkaloids was lowest at the base and tip of the leaf and greatest at the periphery of the leaf and decreased toward the tip of the leaf. Individual nitrosamines were lowest at the tip and the periphery of the leaf. Midvein contained lowest concentrations of NNN, NNK, and NAT at two-thirds length of the leaf and was highest at the base of the leaf. There appeared to be a better relationship between nitrite nitrogen and tobacco-specific nitrosamines than there was with alkaloid content in the leaf.