Photoinduced fragmentation of gas-phase protonated leucine-enkephalin peptide in the VUV range

In this article we report new results for action spectroscopy of protonated peptide Leucine enkephalin (YGGFL). By coupling a linear ion trap mass spectrometer with a vacuum ultraviolet (VUV) synchrotron radiation beamline, we investigate photofragmentation pattern of this peptide, through the analysis of tandem mass spectra recorded over a range of VUV photon energies, below and above the ionization energy. The obtained fragmentation patterns are discussed and compared to previous results