On the question of the occurrence of N-nitroso compounds in tobacco smoke

Abstract

Important facts in connection with the occurrence of N-Nitroso compounds in tobacco smoke have been summarized. This paper reports on analytical methods for the identification of N-Nitroso compounds. The figures known about nitrate content and volatile bases of tobacco, as well as the nitrogen oxides and volatile bases of tobacco smoke as precursors of N-Nitroso compounds, are summarized. The third order reaction of secondary amines with an equimolar mixture of nitric oxide and nitrogen dioxide is a precondition for the formation of N-Nitroso compounds in tobacco smoke. While examining tobacco smoke for N-Nitroso compounds, temperature and time conditions have to be adapted to the natural smoking process. The use of solvent as well as cold traps has to be avoided to exclude the formation of artifacts. Analyses completed under these conditions furnished results of 0.004µg of a mixture consisting of N-Nitroso-dimethylamine and N-Nitroso-pyrrolidine, calculated as N-NO per cigarette. A number of animalexperimental preconditions are still lacking, to judge the biological effects of these extraordinarily small amounts of N-Nitroso compounds.