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

`The utility of gas chromatography with infrared spectrometric detecti on (GC-IR) for the structural elucidation of pyrolysate constituents o btained by Flash Vacuum Pyrolysis (FVP; 900-1100 degrees C, 10(-2) Tor r) of ethynylated Polycyclic Aromatic Hydrocarbons (E-PAH) is demonstr ated. E-PAH are efficient precursors for ubiquitous and genotoxic C14H 8, C16H10 and C20H12 cyclopenta-fused PAH (CP-PAH) combustion effluent s. The formation of CP-PAH from E-PAH as well as CP-PAH rearrangements and/or interconversions are readily recognized. GC-IR being complemen tary to GC-MS enables the identification and structural assignment of previously undetected isomeric PAH, which are only present in trace-le vel amounts. The results are of interest for the elucidation of PAH bu ild up processes and for the rationalization of the ubiquitous formati on of a distinct set of PAH during combustion. (C) 1998 Elsevier Scien ce Ltd. All rights reserved.