Fragmentation of polyatomic molecules by grazing incidence surface-induceddissociation (GI-SID)

The grazing incidence surface-induced dissociation (GI-SID) of n-hexadecylp yridinium and verapamil ions generated by fission fragment desorption was s tudied, These molecules shaw the effect of enhanced surface-induced dissoci ation at grazing incidence as it was observed in former experiments with me tal organic ions. A liquid film of perfluorinated polyether is used as coll ision surface. Small hydrocarbon fragment ions predominate in the GI-SID sp ectra. Pyridine ions appear as specific fragment ions in the GI-SID spectru m of n-hexadecylpyridinium. The GE-SID conversion efficiency varies in the range 40-70%. The experimental results are discussed within the scope of a quantum mechanical model which is based on the accumulation of internal mol ecular energy by resonant excitation of collective vibrational states and e nergy transfer to a trap bond due to dipole-dipole interactions. In this co ntext the GI-SID spectra of n-hexadecylpyridinium and verapamil ions are co mpared with the fragmentation occurring in regular Cf-252 plasma desorption mass spectrometry, Copyright (C) 1999 John Whey & Sons, Ltd.