The application of solid phase extraction to the analysis of tobacco-specific nitrosamines

A new isolation and separation method has been developed for the alkaloid-related nitrosamines in tobacco, called tobacco-specific nitrosamines (TSNA). The improved isolation procedure involves the extraction by sonication of TSNA from cured tobacco with toluene and an aqueous citrate buffer solution, while purification is achieved by solid phase extraction on small silica cartridges. Interfering extract materials are eluted from the silica cartridges with the toluene and a chloroform-methylene chloride solvent, while subsequent elution with chloroform yields the TSNA in a purified fraction. Gas chromatographic analyses on an SE-54-coated glass capillary column and detection by a nitrogen-phosphorous detector produce very good data on the four TSNAs, which include N-nitrosanatabine (NATB), N-nitrosoanabasine (NAB), 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (called NNK), and N-nitrosonornicotine (NNN). The method is shown to be quantitative, reproducible, and applicable to the determination of TSNA in various tobacco samples, such as stems and lamina of cured tobacco leaves, as well as to smokeless tobacco.