4-Aminobiphenyl (4-ABP) is a polycyclic aromatic amine in cigarette smoke. Previous reports indicate that proteinaceous compounds (e.g. amino acids, peptides and proteins) in tobacco can highly contribute to the yield of 4-ABP measured in smoke. In a presentation given at the CORESTA Congress 2012, it was proposed that aromatic ring formation between low-molecular-weight amine compounds and alkyl-substituted benzenes was a major formation reaction for 4-ABP during cigarette combustion. However, it still remains unclear to which extent different pyrolysis conditions can influence the formation of 4-ABP from tobacco. The aim of this study was to clarify the relationship between experimental conditions and 4-ABP yield under non-isothermal pyrolysis of tobacco.

Burley tobacco (BLY) and flue-cured tobacco (FC) were non-isothermally pyrolysed under different pyrolysis conditions by changing the O₂ concentration in the carrier gas N₂, the flow rate of the carrier gas and the target temperature. 4-ABP in total particulate matter was determined by gas chromatography/mass spectrometry after solid phase extraction and derivatisation.

The yield of 4-ABP from BLY decreased by increasing the O₂ concentration in the carrier gas N₂ or by increasing the flow rate of N₂, from ambient temperature to 800 °C. However, these conditions did not significantly change the yield of 4-ABP when pyrolysing FC. The results suggest that the formation of 4-ABP from nitrogenous components in BLY are affected by either O₂ in the atmosphere or the gas flow in the heated layer. Regarding the investigation of the target temperature under N₂ flow, the profile obtained for BLY and FC was similar.

In the presentation, reaction kinetics of the formation of 4-ABP from BLY will also be discussed.