Tandem mass spectrometry: Multisector magnetic instruments

This chapter discusses tandem mass spectrometry. Tandem magnetic sector mass spectrometry was originally developed for investigations of ion chemistry and ion-molecule reaction dynamics. In the mid 1970s, its application to chemical analysis was realized particularly for complex mixtures. However, as tandem mass spectrometry evolved, it became clear that its major application was in determining the structure of biomolecules and that truly complex mixture analysis was better accomplished by incorporating some kind of chromatography in the analytical protocol. Its utility for mixture analysis is not to be negated because many isolates of biomolecules, even after chromatographic separation, are mixtures. Thus, the structure determination or identification of the analyte requires both separation and analysis, both of which can be accomplished with this method. Tandem mass spectrometry has gained with acceptance in determining peptide sequences, especially because of the high structural diversity of peptides, their importance in biochemistry, and the limitations of other more classical methods (e.g., Edman degradation).