Unravelling seemingly complex chemistry of reactions using electrospray ionization mass spectrometry

Since its discovery, electrospray ionization mass spectrometry (ESI-MS) has provided valuable information on structurally specific biomolecular intera ctions, including DNA-drug, enzyme-inhibitor, DNA-protein and protein-prote in interactions. In addition, this technique has emerged as a powerful tool in probing the structural modification of large molecules. However, ESI-MS has been underutilized in analysis and mechanistic studies involving small molecules. Here, a brief overview is presented to familiarize non-speciali sts with ESI-MS applications in analysis and mechanistic studies of small m olecules. For more advanced applications (e.g. biopolymers) or detailed ana lytical descriptions of the ionization processes and the equipment, readers are referred to a number of excellent reviews and books. Copyright (C) 199 9 John Wiley & Sons, Ltd.