Tandem mass spectrometry general principle

To benefit general readers, the discussion has been limited to methodologies that are accessible to nonspecialists and that can be carried out on commercially available spectrometers without special modifications. The chapter illustrates the principles of mass spectrometry by demonstrating how various techniques [MALDI, ESI, Fourier transform ion cyclotron resonance (FT-ICR), ion traps, and tandem mass spectrometry (MS-MS)] work. It also provides examples of utilizing mass spectrometry to solve biological and biochemical problems in the field of protein analysis, protein folding, and noncovalent interactions of protein-DNA complexes. 

This section deals with some general principles of tandem mass spectrometry and its applicability to quantitative analysis. The MS/MS acronym is used in this book as a general term for aU tandem mass spectrometry techniques. More detailed descriptions of how the principles are exploited in practice for the various instrumental types are given in later sections of this chapter. The general concept of tandem mass spectrometry in qualitative (structural) analysis is that additional chemical information, over and above that contained in a conventional onedimensional mass spectrum, can be obtained by examining the connectivity relationships among some or all of the ions in that mass spectrum. The connectivities arise as a result of the dissociation reactions that lead to the fragment ions in a mass spectrum, e.g. ... 

In principle, both instrumental concepts can be expanded to allow for multiple-stage mass spectrometry, i.e., multiple stages of precursor ion selection followed by product ion detection for successive n generation product ions [6]. While it is convenient to talk about MS/MS, acronyms like MS/MS/MS are clearly out of place. Therefore, it is common practice to use MS, MS, and generally MS" to denote the number of stages of a tandem mass spectrometric experiment. Accordingly, in the sequential fragmentation scheme... 

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