SPECIAL FEATURE: TUTORIAL Electrospray: Principles and Practice

The basic principles underlying the electrospray process are reviewed without recourse to detailed discussion of mechanisms. The essential features of the practical implementation of electrospray (at various solution Ñow rates) are described and the nature of the resultant gas-phase ion population is discussed. The generation by electrospray of multiply charged ions creates complications in that spectral complexity is increased and the determination of charge number must precede the measurement of mass. Multiple charging is beneÐcial, however, in extending the mass range and improving fragmentation yield in tandem mass spectrometry. The current breadth of application of the technique (including the analysis of non-covalently bound species) and future developments are discussed