Analytical applications of ion-molecule reactions

Abstract

This review covers applications of ion-molecule reactions for solving increasingly complex analytical problems. Because gas-phase reactions are frequently fast and efficient, the use of ion-molecule reactions provides a diverse frontier for extending the boundaries of mass spectrometry. Product distributions from ion-molecule reactions may provide key diagnostic information for structure identification, and particular product ions may afford more structurally informative fragmentation patterns than those patterns of ions that are generated by conventional methods. Applications range from those areas involving the development of novel chemical ionization reagents that show structural specificity upon reactions with analytes, to those areas in which ion-molecule reactions are combined with collisionally activated dissociation in unusual sequences, to those areas involving ion-molecule reactions of species formed by laser desorption or electrospray ionization. In electrospray ionization applications, the use of ion-molecule reactions allows the concentration of ion current into fewer multicharged ions, permits the counting of acidic or basic sites, and provides indirect information about protein structures and thermochemical data about individual sites in large molecules. © 1997 John Wiley & Sons, Inc., Mass Spectrom Rev 16 (2), 91–110, 1997