Quantification of tobacco specific nitrosamines in tobacco
An analytical procedure was developed for the extraction and quantification of tobacco specific nitrosamines (TSNA) : N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N'-nitrosoanabasine (NAB), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). Tobacco was extracted with a citrate-phosphate buffer and the buffer was back-extracted into methylene chloride (MeCl2). The MeCl2 extract was partially evaporated, diluted to a constant volume, and analyzed by gas chromatography with detection by a thermal energy analyzer (TEA). Quantification was performed using an internal standard technique. The chromatographic precision for NNN, NAT, and NAB was about 5% while that for NNK was about 9% due to its poor peak shape. The overall precision using internal standard quantification was found to be better than that based on an external standard and was < 8% for NNN, NAT and NNK. The overall precision for NAB was about 25% due to its low concentration in tobacco. The response was linear for TSNA, and recoveries were > 80%. Several tobacco types were analyzed for their amounts of TSNA.