Cigarette smoking is an extremely complex and dynamic chemical process. The gas phase chemistry of tobacco combustion in the tobacco voids and pores is difficult to address by conventional analytical methods. Recently photo ionisation mass spectrometry (PIMS) was established as a fast on-line analytical technique to analyse the chemical signature of highly dynamic combustion and pyrolysis processes in cigarettes^[1]. A new combination of PIMS (laser-based single photon ionisation, 118 nm) and a capillary microprobe sampling system (µ-probe) for direct examination of the composition of organic vapours in the centre of the cigarette’s combustion zone was developed^[2]. Here this µ-probe-PIMS-approach is applied as a spatial and temporal resolved mapping method. Repetitive smoking experiments with a reproducible smoke machine and standard reference cigarettes were performed and different sampling positions in the cigarette rod were multiply addressed by µ-probe PIMS-measurements. The time-resolved PIMS-sequences were later combined to spatially-resolved, time-dependent “maps” for the different compounds. This new imaging technique was used to measure quantitative distributions of e.g. nitrogen monoxide, benzene and oxygen in the burning tip of a cigarette during a 2 second puff (with up to 100 ms time resolution). The different formation and destruction zones of the investigated compounds in the reaction region and their dynamic changes were observed during the puff, and space-resolved kinetic data was obtained. For example, the classical formation and destruction mechanisms of NO during the puff (fuel-NO formation and re-burn in hydrocarbon rich zones) were observed resolved in space and time.

[1] Adam, T. et al., Anal. Chim, Acta 657 (2010) 36-44
[2] Hertz, R., et al., Analytica Chimica Acta, 714 (2012) 104-113