Levels of nicotine in Ethiopian tobacco leaves.

Tobacco is a valuable cash crop. It is the most widely grown non-food crop in the world. Tobacco use is widespread due to its addictive nature of its main constituent nicotine. Therefore, the knowledge of nicotine level in tobacco is important to tobacco industry and in the area of toxicology to control its harmful effect on health. There is no report in the literature on nicotine level of Ethiopian raw (unprocessed) tobacco leaves. Hence, the objective of this study is to determine the levels of nicotine in the Ethiopian tobacco leaves. Samples were collected based on their leaves positions, species and place of cultivation from different regions of Ethiopia. These were Virginia type tobacco from Shewa Robit and Billate, Burley and Oriental types of tobacco from Awassa and native tobacco used as pipe smoking (Gaya) from Wollayita. The level of nicotine in four different varieties of Ethiopian tobacco leaves was determined using high performance liquid chromatography. The level of nicotine in the four different varieties of Ethiopian tobacco were Virginia tobacco (3.26 %), the native tobacco 'Gaya' (1.10 %), Burley tobacco (0.650 %), and Oriental tobacco leaves (≤0.0500 %). It was found that the nicotine level of Ethiopian Virginia tobacco leaves increases from bottom to top leaf (stalk) positions of the tobacco plant. It was also found that the nicotine level of Ethiopian tobacco leaves varies in different species and the nicotine level of the same tobacco species differ in different area of cultivation. In general, the level of nicotine in Ethiopian tobacco is comparable with that in the rest of the world.