Analysis the formation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in tobacco smoke generated from pyrolysis under inert and oxidative conditions respectively

- The contents of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone in smoke (Air) were much higher than that in tobacco leaves and in smoke (N2).
- Nicotine and active nitrogen oxides are principal precursors and reducing sugars could prohibit the formation of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone in smoke.
- The main reason for the difference of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone formation in tobacco leaves and smoke is the source of active nitrogen oxides.

4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone is an important and abundant strongly carcinogenic agent in tobacco leaves and its smoke, hence 15 kinds of tobacco samples were collected to study the formation of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone in the tobacco smoke generated by pyrolysis under inert and oxidative conditions respectively. Contents of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone in tobacco leaves and in the smoke were compared. The effects of nicotine, reducing sugar, O2, nitrate and nitrite salts on the release of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone were also investigated. The results show that: 1) the contents of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone in smoke under oxidative condition were much higher than that in tobacco leaves and in smoke under inert condition; 2) nicotine and active nitrogen oxides are principal precursors and reducing sugars could prohibit the formation of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone in smoke; 3) nitrate and nitrite salts can give rise to the release of 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone in smoke (Air) dramatically, but nitrite showed less effective than nitrate; 4) O2 not only can react with nitrate and nitrite salts to decompose active nitrogen oxides, but also can react with the nitrogen-containing compounds in tobacco leaves at high temperatures, which provided more active nitrogen oxides combined with nicotine to produce 4-(methylnitrosamino)-l-(3-pyridyl)-1-butanone.