Photofragmentation studies of biomolecular ions of amino acids using a tandem reflectron time-of-flight mass spectrometer

A tandem reflectron time-of-flight mass spectrometer developed in Glasgow University was used for the investigation of photofragmentation of the molecular ions of the amino acid derivatives: PTH-tryptophan, PTH-valine, and PTH-alanine as well as of cytosine and guanine, The molecular ions were generated by matrix-assisted laser desorption/ionization and the laser photofragmentation of selected ions took place at the turn-around point of ions in the reflectron. The fragmentation mass spectra of the molecular ions of these amino acid derivatives have been observed and possible fragmentation pathways are discussed.