Ion Sources not Requiring a Discrete Interface

The fast atom bombardment (FAB) ionization technique is of great historical importance in mass spectrometry, as it provided tbe first facile approach to applications to fragile biomolecules. When first introduced (Barber 1981), FAB created a sensation within the mass spectrometry community hut was supplanted after a few years by the newer techniques of electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI). FAB is still used for some specialized applications. It was first developed as a means of overcoming an intrinsic limitation of 

From the viewpoint of trace analysis by mass spectrometry interfaced online with HPLC, flow-FAB interfaces 

An investigation of matrix effects in EAB (ionization suppression, again enhancement has not been reported) caused by ionic surface active compounds has rationalized the unexpected finding that, while cationic surfactants do suppress ionization of glycerol matrix in positive mode this is not true in negative mode, and vice versa (Kosevich 2007). This paper is an extension of previous work (Kosevich 2003) that rationalized many otherwise puzzling features of FAB ionization through the realization that a FAB matrix in the ion source vacuum is a superheated liquid. 

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