Fragmentation (mass spectrometry)

Fragmentation can occur in the ion source (in-source fragmentation) where it has been used with electron ionization electrospray ionization in-source fragmentation was generally considered an undesired effect however, electrospray ionization using Enhanced In-Source Fragmentation/Annotation (EISA) has been shown to promote in-source fragmentation that creates fragment ions that are consistent with tandem mass spectrometers. ==Fragmentation reactions==

Fragmentation is a type of chemical dissociation, in which the removal of the electron from the molecule results in ionization. Removal of electrons from either sigma bond, pi bond or nonbonding orbitals causes the ionization. Radical site-initiated fragmentation Sigma bond cleavage also occurs on radical cations remote from the site of ionization. This is commonly observed in alcohols, ethers, ketones, esters, amines, alkenes, and aromatic compounds with a carbon attached to ring. The cation has a radical on a heteroatom or an unsaturated functional group. The driving force of fragmentation is the strong tendency of the radical ion for electron pairing. Cleavage occurs when the radical and an odd electron from the bonds adjacent to the radical migrate to form a bond between the alpha carbon and either the heteroatom or the unsaturated functional group. The sigma bond breaks; hence this cleavage is also known as homolytic bond cleavage or α-cleavage. ==See also==