Determination of the collisionally activated dissociation of a substitutedindole by orthogonal acceleration quadrupole time-of-flight mass spectrometry

The use of orthogonal acceleration quadrupole time-of-flight (Q-TOF) mass s pectrometry to determine the collisionally activated dissociation (CAD) of a test compound 1-(3-[5-{1,2,4-triazol-4-yl}-1H-indol-3-yl]propyl)-4-(2-{3- fluorophenyl}ethyl)piperazine is described. At unit-mass resolution the ide ntity of many ions is ambiguous because of the complexity of the resulting product ion spectrum. Using the high resolution capabilities of the Q-TOF i nstrument, exact masses for each fragment were determined. These data were used to infer molecular formulas for each fragment through software interpr etation and, by further applying chemical intuition, the majority of ions w ere fully assigned. Additionally, by utilizing in-source fragmentation at h igh cone voltage, analyses of second-generation products allowed derivation of a consistent sequential fragmentation pathway. This study clearly demon strates the power of Q-TOF mass spectrometry to elucidate complex product i on spectra. (C) 2001 American Society for Mass Spectrometry.