Fast‐Atom bombardment mass spectrometry and collisional spectroscopy in the structural characterization of underivatized 1,4‐benzodiazepines

Abstract Fast‐atom bombardment (FAB) mass spectrometry linked with collision spectroscopy has been employed for the structural characterization of eight underivatized 1,4‐benzodiazepines. Both positive‐ and negative‐ion FAB led, in all cases examined, to the production of abundant molecular species. Collision experiments performed on such ions gave rise to the identification of diagnostic fragment ions, that could be related to the original structure.