PNNL

Abstract

Collision-induced and surface-induced dissociation of protonated dialanine (Ala-AlaH+) was studied using a 7 T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR MS). Energy-resolved fragmentation efficiency curves were obtained using both techniques. The results were modeled using RRKM/QET formalism. The energetics and dynamics of the four primary and some secondary fragmentation pathways were determined from the RRKM modeling. Both multiple-collision CID and SID results could be reproduced within the same model. The strong correspondence of fragmentation efficiency curves obtained in the high-pressure CID and SID experiments indicates that the internal energy distributions of Ala-AlaH+ activated by multiple collisions and by surface impact are remarkably similar.