Ion internal energy selection through angle-resolved mass spectrometry

Abstract

Collision-induced dissociation of kilovolt energy ions gives product ions whose nature and abundance depend on the scattering angle. Increasing angle corresponds to depositing increased internal energies. The angle-resolved data for methanol, ethanol, propan-1-ol, methane, and propane closely parallel the breakdown curves for these molecular ions. Fragmentations from isolated electronic states are suggested by the angle-resolved data for CS +- 2. The results provide further evidence that collisional activation at kilo-electron volt energies occurs by direct electronic excitation. This methodology is also shown to allow the effectiveness of different targets in collisional activation to be determined.