Pyrolysis

X X + A + B + C ⎫ Xa Xa + Aa + Ba + Ca | X1 X1 + A1 + B1 + C1 | Entities interact X2 X2 + A2 + B2 + C2 | with one another X3 X3 + A3 + B3 + C3 ⎬ Cigarette smoke … ….. | Plus transfer of … ….. | intact X and Xa | as well as … ….. | intact Xn Xn + An + Bn + Cn ⎭ X1, X2, X3, … ,Xn

Products obtained from the thermal degradation of [14C] nicotine in a combustion tube (under pyrolytic conditions) and in a cigarette (undergoing machine smoking) were examined by gas-liquid chromatography (GLC), by GLCmass spectrometry, and by radiochromatography. Under pyrolytic conditions in a combustion tube, nicotine underwent extensive degradation to pyridines, quinoline, arylnitriles, and aromatic hydrocarbons. In contrast, in a burning cigarette, a substantial portion of nicotine remained intact (≈41%), 12.5% underwent oxidation to CO2, up to 11% was degraded to volatile pyridine bases, and negligible amounts were converted to neutral or acidic particulate components. A major portion of nicotine and its degradation products was also diverted to sidestream smoke. These results suggest to us that pyrolysis experiments may be limited for establishing the fate of nicotine and possibly other tobacco components in a burning cigarette.