Formation of Ions in Chemical Ionization

In chemical ionization new ionized species are formed when gaseous molecules interact with ions. Chemical ionization may involve the transfer of an electron, proton, or other charged species between the reactants. [8] These reactants are i) the neutral analyte M and ii) ions from a reagent gas. 

Note It is commonplace to denote [Mh-H] and [M-H] ions as quasimolecular ions because these ions comprise the otherwise intact analyte molecule and are detected instead of a molecular ion when Cl or other soft ionization methods are employed. Usually, the term is also applied to [M-i-alkali] ions created by other soft ionization methods. 

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