A comparative study on the physicochemical properties of tobacco ash from lit bright cigarettes with different cut tobacco fillers

摘要

The physicochemical properties of tobacco ash under different combustion pyrolysis simulation conditions and in different areas of lit cigarettes rolling from various cut tobacco fillers were investigated using optical image, cigarette ash integrity (CAI), chromatic aberration (CA), scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS), fourier transform infrared spectrometer (FTIR) and microscale combustion calorim-eter (MCC), respectively. The study of ash appearance showed that lit cigarettes rolling from expanded cut stem (ECS) and reconstituted tobacco (RT) had lighter grey for the outer cigarette paper ash and darker color for the inner cut tobacco ash than those rolling from flue-cured tobacco (FCT) and expanded cut tobacco (ECT), respectively. Further study of CA and combustion rate indicated cigarette with ECS showed a highest burning rate and Delta L, followed in order by RT, ECT and FCT. SEM results displayed that various tobacco's microstructures were still preserved at 450 degrees C, but fully broken at 750 degrees C and in the ash area of lit cigarettes, and then replaced by thin surface set with many particles for FCT, many connected lines coated with tiny particles for ECT, surface embedded with many rods for ECS and particle-containing surface for RT at 900 degrees C. EDX results illustrated that the above newly formed microstructures at 900 degrees C are mainly composed of O, C, Ca, Mg, K Cl, S and P, with a small amount of Fe, Al, Si, Mn and Co, of which some elements like K, S, P and Cl showed a migration into the gas phase. It can also obtained from EDX results that ECS left maximum C/O, K and Cl in the burning cone and tobacco ash area, followed in order by RT, FCT and ECT. FTIR study showed that carbonates have been produced substantially in the combustion cone for ECS, but just generated a little for FCT, ECT and RT. MCC analysis demonstrated that RT's coke had the lowest thermal stability, while ECS's coke began to release heat at lower temperature and ended at higher temperature in comparison with FCT and ECT. The correlation analysis showed that the ash appearance of burning cigarettes can be enhanced via a rise of K/Cl, K/S and K/(Cl+S) and a reduction of nicotine and ratio of sugar to nicotine.