Electron-impact-induced fragmentation of proline molecule

The formation of ionized products upon single and dissociative ionization of proline (C$_5$H$_9$NO$_2$) molecule by electron impact at high (11.5 MeV) and low (below 150 eV) energies has been studied using mass-spectrometric techniques. The mass-spectra of proline molecule have been obtained and interpreted and the near-threshold fragment ion yields have been measured, from which the absolute values of ionization energies of the initial molecule and the appearance potentials of its main fragment ions are determined. Analysis of the influence of exposure to a high-energy beam of accelerated electrons on the resulting mass spectra of initial molecules showed that high-energy irradiation produces irreversible changes in the initial molecular structure.