Identification of isomeric polycyclic aromatic hydrocarbons (PAH) in pyrolysates from ethynylated PAH by gas chromatography-Fourier infrared spectroscopy. Their relevance for the understanding of PAH rearrangement and interconversion processes during combustion

Abstract The utility of gas chromatography with infrared spectrometric detection (GC-IR) for the structural elucidation of pyrolysate constituents obtained by Flash Vacuum Pyrolysis (FVP; 900–1100°C, 10 −2 Torr) of ethynylated Polycyclic Aromatic Hydrocarbons (E-PAH) is demonstrated. E-PAH are efficient precursors for ubiquitous and genotoxic C 14 H 8 , C 16 H 10 and C 20 H 12 cyclopenta-fused PAH (CP-PAH) combustion effluents. The formation of CP-PAH from E-PAH as well as CP-PAH rearrangements and/or interconversions are readily recognized. GC-IR being complementary to GC-MS enables the identification and structural assignment of previously undetected isomeric PAH, which are only present in trace-level amounts. The results are of interest for the elucidation of PAH build up processes and for the rationalization of the ubiquitous formation of a distinct set of PAH during combustion.