Energy-resolved tandem and fourier-transform mass spectrometry

Abstract

Both Fourier-transform mass spectrometry and tandem mass spectrometry can be used to obtain the collision-energy dependence of MS/MS spectra- Qualitative agreement between the results of these methods is observed for the fragmentations of ionized propane. 2-pentanone. n-butylbenzene, n-propylbenzene and perfluoropropylene in the 1–50 eV range of collision energies. Both experiments are performed readily and serve as an information-rich means of characterizing particular mass-selected ions. When the results are plotted in the form of breakdown curves, good agreement is observed with available data obtained from photoion-photoelectron coincidence experiments and quasi-equilibrium theory. Agreement is also obtained for experiments in which ion internal energy is specified by selecting the scattering angle associated with collision-induced dissociation. Only for n-butylbenzene, in comparison with photodissociation, and for perfluoropropylene, in comparison with literature data for low-energy electron excitation, are serious discrepancies observed. Incomplete equilibration of excitation energy (non-ergodic behavior) is indicated.