Neutral solutions bombardment with

Fast atom bombardment the sample in solution in a non-volatile solvent such as glycerol is ionized under vacuum by bombardment with accelerated neutrals such as argon. 

The greater part of the studies have been performed with iron in neutral solutions. Ashworth et al. examined in detail the behavior of ion-bombarded iron in buffered acetic acid solution (pH = 7.3). At first they looked into the effect caused by argon ion implantation The potentiokinetic polarization curves showed some differences between the unimplanted and the argon-implanted iron specimen, but only for the first sweep. This indicates the initial presence of an air-formed fUm which is thicker for the implanted sample than for the untreated iron, as already indicated in the preceding section. Once the film had been removed by cathodic reduction there were no significant differences in the potentiokinetic polarization behavior of the two samples. 

The classicaf FAB ionization technique consists in the bombardment of the sample dissolved in a nonvolatile, viscous, and polar liquid (the matrix) with neutral xenon atoms. However, a much more popular version is Liquid-matrix Secondary-ion Mass Spectrometry (LSIMS) in which the sample solution is bombarded with heavy ions, usually Cs+ or Xe+. Basic information about FAB and LSIMS can be found in mass spectrometry monographs [3, 4]. Comprehensive reviews on the application of FAB for analyzing biomolecules [5-7] and, specifically, saccharides and glycoconjugates [8] are also available. 

Bombardment of a neutral molecule with electron beam provides molecular ion (or parent ion) but in many cases this ion is too unstable to be present in the spectrum. The fragmentation process executed under constant conditions is well understood. The analyte fragmentations in El mass spectra may provide information to determine molecular mass, elemental formula, and substitution patterns. In some cases El does not provide sensitivity sufficient for the analysis of very small amounts of solute. 

---