CORESTA Meeting, Smoke/Technology, Innsbruck, 1999, ST01

Analytical approaches for the determination of tobacco alkaloids

Philip Morris USA, Richmond, VA, USA
Tobacco alkaloids of interest include nicotine, nornicotine, myosmine, anabasine and anatabine. In the past, several analytical approaches were tested for the analysis of these compounds, involving the use of HPLC, capillary electrophoresis, and GC or GC/MSD with the combination of a solventless sampling technique, solid-phase microextraction. The experimental parameters and analytical results of these methods will be briefly reviewed as background information for the audience. The focus will remain on an improved GC-NPD (nitrogen-phosphorous detector) method, which is currently used for the determination of alkaloids in tobacco. Tobacco samples were treated with a small quantity of aqueous ammonium hydroxide solution to 'loose' tobacco tissue and to control pH, followed by extraction using organic solvent. The selection of extraction solvent influences the recoveries of alkaloids, particularly nornicotine, as well as the other problems such as carry-over at the injection liner and 'quenching' at the NPD detector. The question of whether a packed injection liner (e.g., with Carbowax/KOH on Chromsorb) is needed to resolve the carry-over problem was studied. The quenching problem of a NPD detector was reduced by increasing the split ratio, which resulted in a loss of sensitivity. Thus, a narrow bore capillary column was applied to improve sensitivity and to speed up GC analysis. More detail information along with statistical data from method validation and sample analysis will be presented.