Chiral liquid chromatography-tandem mass spectrometry for enantiomeric profiling of ten alkaloids in tobacco: Assessing interconversion in precursor materials and aerosol

Multiple chiral enantiomer separation poses challenges in analyzing complex matrices like natural plant materials. Currently, there is no straightforward method for simultaneous separation and analysis of ten alkaloids and enantiomers, mainly due to most of their low levels. Here, we present an improved chiral liquid chromatography-tandem mass spectrometry method for accurate quantification of ten alkaloids and enantiomers. This method exhibits recoveries of 92.3 to 118.1 %, intra-day precisions of 0.6 to 4.7 %, and inter-day precisions of 1.2 to 4.5 %, with detection limits ranging from 0.03 to 3.0 ng/mL. Successfully applied to the ten alkaloids and enantiomers quantification in precursor tobacco materials and aerosols from traditional cigarettes and heated tobacco products, our results show higher concentrations of ten alkaloids in traditional cigarette aerosol compared to heated tobacco products aerosol. During aerosol formation, (R)-cotinine, N-methylanabasine, and β-nornicotyrine were produced. Notably, high temperatures during aerosol formation favored the (R)-enantiomer of several chiral alkaloids, and lead to the formation of new secondary alkaloids. This proposed mechanism represents the first attempt to elucidate the interconversion of alkaloids during aerosol formation.