Chemical Studies on Tobacco Smoke. III. Primary and Secondary Nitroalkanes in Cigarette Smoke

An analytical method for the isolation and identification of nitroalkanes in cigarette smoke was developed. The analytical procedure includes water steam-distillation of cigarette smoke condensate and several extraction steps. The final concentrate of the nitroparaffins is separated into individual components by gas chromatography on 5 % Apiezon N and 5 % Armeen SD on fire brick. Utilizing a flame ionization detector system for the final analysis, 200 cigarettes had to be smoked. When an electron detector system was utilized the smoking of 20 cigarettes sufficed for the analysis of six nitroalkanes. These were identified by relative retention times and volumes, and the fragmentation patterns of the individual nitroalkanes. The presence of a seventh nitroalkane was ascertained and it was tentatively identified as a nitropentane. The smoke of one 85 mm blended United States cigarette without filter tip contained 0.53 µg nitromethane, 1.1 µg nitroethane, 1.1 µg 2-nitropropane, 0.73 µg 1-nitropropane, 0.71 µg 1-nitro-n-butane and 0.22 µg 1-nitro-n-pentane. The analysis of the smoke of 10 different cigarettes demonstrated a correlated increased yield of six nitroparaffins with increased nitrate content of the cigarette tobacco. This result supports our working hypothesis that nitrogen oxides formed during the pyrolysis of alkali nitrate in tobaccos react as scavengers with organic radicals in the hot zones of burning cigarettes and tend to inhibit the synthesis of aromatic hydrocarbons, including those with known carcinogenic effects to experimental animals.