Time and spatially resolved in-situ temperature and pressure measurements with soft ionisation mass spectrometry inside a burning superslim cigarette. Part II – thermochemical mapping
Superslim cigarettes are an increasingly popular category of cigarettes in China. Accurate measurements of key thermophysical and thermochemical parameters in superslim cigarettes is essential for mechanistic understanding of pyrolysis processes, thermal desorption, combustion properties and quality control. The second part of a comprehensive mechanistic study on superslim cigarettes investigated the thermochemical reactions reflected by selected key combustion and pyrolysis marker compounds, all mapped using a fast in situ chemical sampling technique. In addition to the integrated temperature and pressure sensors presented in the first part of this work, a fast in situ chemical sampling technique was also synchronised with these sensors and used to obtain detailed chemical information from this dynamic combustion system in response to the ISO airflow protocol. The single heated 0.5 mm chemical sampling microprobe, coupled to a single-photon soft ionisation (SPI) mass spectrometer through a heated transfer line, was also inserted to extract highly time and spatial resolved data from the superslim combustion system. The novel approach allowed the comprehensive description as a synthesis of complex and dynamic variating data of the main thermophysical and thermochemical phenomena. Time-resolved mapping of e.g. benzene, nicotine and NO was used to illustrate thermal desorption, combustion and pyrolysis as formation-led chemical reactions. Furthermore, degradation pathways of e.g. nicotine to indole and ammonia can be spatially correlated to temperature and flow distribution conditions in the cigarette.