Electron ionization (EI, formerly known as electron impact ionization[1] and electron bombardment ionization[2]) is an ionization method in which energetic electrons interact with solid or gas phase atoms or molecules to produce ions.[3] EI was one of the first ionization techniques developed for mass spectrometry.[4] However, this method is still a popular ionization technique. This technique is considered a hard (high fragmentation) ionization method, since it uses highly energetic electrons to produce ions. This leads to extensive fragmentation, which can be helpful for structure determination of unknown compounds. EI is the most useful for organic compounds which have a molecular weight below 600 amu. Also, several other thermally stable and volatile compounds in solid, liquid and gas states can be detected with the use of this technique when coupled with various separation methods.[5]
- ^ T.D. Märk; G.H. Dunn (29 June 2013). Electron Impact Ionization. Springer Science & Business Media. ISBN 978-3-7091-4028-4.
- ^ Harold R. Kaufman (1965). Performance Correlation for Electron-bombardment Ion Sources. National Aeronautics and Space Administration.
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "electron ionization". doi:10.1351/goldbook.E01999
- ^ Griffiths, Jennifer (2008). "A Brief History of Mass Spectrometry". Analytical Chemistry. 80 (15): 5678–5683. doi:10.1021/ac8013065. ISSN 0003-2700. PMID 18671338.
- ^ Dass, Chhabil (2007). Fundamentals of Contemporary Mass Spectrometry - Dass - Wiley Online Library. doi:10.1002/0470118490. ISBN 9780470118498. S2CID 92883349.