Fragmentation (chemistry)

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Fragmentation is a type of chemical dissociation. Fragmentation of a molecule can take place by a process of heterolysis or homolysis.

It is a phenomenon used in mass spectrometry to find the structural formula of a molecule through mass spectrum analysis, process called structural elucidation.

It can occur in the ion source (in-source fragmentation) where it is generally not a desired effect. Ion source conformation is an important criterium in the level of fragmentation observed.

IUPAC definition

Breakdown of a material to particles regardless of the mechanism and the size of fragments.

Note: Modified from ref.[1] in order to remove size limitation.[2]

Desired fragmentation is made in the collision zone (post-source fragmentation) of a tandem mass spectrometer. It is a part of gas phase ion chemistry and there are different types of mass fragmentation:

Schemes of fragmentation[edit]

The certain structures favour fragmentation the α-cleavage and the McLafferty rearrangement are two examples for the often observed fragmentations.

Other schemes includes Heterocyclic ring fission (HRF), benzofuran forming fission (BFF), quinone methide (QM) fission or Retro Diels-Alder (RDA).[3]

See also[edit]


  1. ^ Plastics. Guide for vocabulary in the field of degradable and biodegradable polymers and plastic items. BSI. 2006. ISBN 0 580 49611 2. 
  2. ^ "Terminology for biorelated polymers and applications (IUPAC Recommendations 2012)". Pure and Applied Chemistry: 377–410. 2012. doi:10.1351/PAC-REC-10-12-04. 
  3. ^ Tandem Mass Spectrometry for Sequencing Proanthocyanidins. Hui-Jing Li and Max L. Deinzer, Anal. Chem., 2007, volume 79, pages 1739-1748, doi:10.1021/ac061823v

External links[edit]