Application of time-of-flight mass spectrometry with laser-based photoionization methods for analytical pyrolysis of PVC and tobacco

PVC and tobacco samples were pyrolyzed in a rotary furnace at different temperatures and reaction gas compositions. Released gaseous products were analyzed using single photon ionization (SPI)/resonance enhanced multiphoton ionization (REMPI)-time-of-flight mass spectrometry (TOFMS). These soft and selective ionization techniques allow fast and comprehensive on-line monitoring of a large variety of aliphatic and aromatic substances without fragmentation of the molecular ions. The thermal decomposition of PVC led to the appearance of chlorinated aromatic compounds at trace levels, which could be detected with SPI-TOFMS. Polycyclic aromatic hydrocarbons (PAH) were simultaneously accessible by REMPI-TOFMS. Different tobacco types can be distinguished by photoionization mass spectrometry of their gaseous pyrolysis products. In addition, pyrolysis products can be classified in three groups depending on their behaviour at different pyrolysis temperatures, which might help to unravel formation mechanisms and chemical pathways of hazardous substances.