Event-by-event analysis of collision-induced cluster-ion fragmentation: sequential monomer evaporation versus fission reactions

A novel "correlated ion and neutral time of flight" method: event-by-event detection of neutral and charged fragments in collision induced dissociation of mass selected ions

A new tandem mass spectrometry (MS/MS) method based on time of flight measurements performed on an event-by-event detection technique is presented. This "correlated ion and neutral time of flight" method allows to explore Collision Induced Dissociation (CID) fragmentation processes by directly identifying not only all ions and neutral fragments produced but also their arrival time correlations within each single fragmentation event from a dissociating molecular ion. This constitutes a new step in the characterization of molecular ions. The method will be illustrated here for a prototypical case involving CID of protonated water clusters H(+)(H2O)n = 1-5 upon collisions with argon atoms.