Spatially resolved aerosol characterization during thermal distillation and pyrolysis of tobacco using an in-situ microprobe sampling coupled with fast particulate spectrometer

Potential human health and environmental issues associated with aerosol release as a result of biomass pyrolysis have received a widespread attention. Accurate aerosol sampling at source can help to unravel the complex mechanisms involved. This paper describes a novel aerosol microprobe sampling system combined with a smoking cycle simulator and a differential mobility spectrometer (microprobe-SCS-DMS) for spatially resolved in-situ characterization of aerosol release inside a heated tobacco product. A purposely made microprobe was accurately positioned to sample the aerosol generated at different positions within the heated distillation and pyrolysis zone. The aerosol particle behaviour at source was studied under a combined heating and air-flow cycle. Detailed measurements on the aerosol formed from both the axial and radial directions inside the heated tobacco rod were obtained, including the aerosol particle size distribution, particle number concentration, and particle volume concentration during external air flow perturbation. The results provided detailed information on the formation, diffusion, transfer and filtration of the aerosol which would otherwise not be possible. The microprobe-SCS-DMS system described in this work could be useful for other similar challenges involving aerosol in-situ characterization.