Determination of nicotine-related alkaloids in tobacco and cigarette smoke by GC-FID

A simple and accurate method, gas chromatography (GC) with flame-ionization detection (FID) has been used for determination of the four main nicotine-related alkaloids in tobacco. Tobacco samples were treated with a small quantity of aqueous ammonia solution, to loosen the tobacco tissue and to convert all alkaloids to free bases, then extracted with 1:3 CH3OH-CH2Cl2. A method for further simultaneous and comprehensive determination of six nicotine-related alkaloids in cigarette smoke was also developed. Because of the complexity of the cigarette smoke matrix and the small amounts of alkaloids, except nicotine, in cigarette smoke, the smoke extract was concentrated after removal of the acidic and neutral fractions. To reduce the adsorption and thermal degradation of alkaloids in the liner, especially for nornicotine, a suitable injector temperature was selected and pulsed injection mode was studied. Different cigarette smokes and tobaccos were analyzed for levels of nicotine-related alkaloids.