Evaluation of several minor alkaloid levels in tobacco with separation of R- and S-nornicotine

Abstract

The chiral separation of minor alkaloids from tobacco is of interest because R and S isomers of these compounds have differences in their physiological activity. This difference is also reflected in the physiological properties of tobaccospecific N'-nitrosamines (TSNAs), in particular that of N'- nitrosonornicotine. This compound results mainly from nornicotine nitrosation. The previously reported analytical techniques for the enantiomer separation of minor alkaloids have various shortcomings, such as the need for bidimensional chromatography or poor enantiomer separation. A new method for the analysis of nornicotine, anabasine and anatabine has been developed, based on an original derivatization and a simple gas chromatography/mass spectrometry (GC/MS) analysis. The method allows separate quantitation of S-nornicotine and Rnornicotine, and the analysis of anabasine and anatabine (without isomer separation). It was found that the proportion of S-nornicotine in the total nornicotine present in tobacco varies, depending on the tobacco type, between 52.6% for a flue-cured tobacco to 91.4% for a Burley. Green tobaccos (freeze dried) showed lower levels of minor alkaloids and S-nornicotine accounted for between 31.6% to 43.8% of the total nornicotine (in the analyzed samples).