Unimolecular and collision induced fragmentations of molecular ions of polycyclic aromatic hydrocarbons

The unimolecular and collision induced fragmentation reactions of 19 polycyclic aromatic hydrocarbons have been investigated, using B/E linked scans, accelerating voltage scans, and measurements of appearance energies. From the point of view of simple analytical fingerprinting within isomeric series, B/E linked scans without collision gas offered the best compromise. Attempts to correlate trends observed in fragmentation intensities with various molecular parameters were generally unsuccessful, although some tentative conclusions have been drawn. The evidence concerning fragmentation mechanisms and ion structures is also discussed.