Chemical ionization (CI) is an ionization technique used in mass spectrometry.

Ionization of sample (analyte) is achieved by interaction of its molecules with reagent ions. The analyte is ionized by chemical ion-molecule reactions during collisions in the source. This is a less energetic procedure than electron ionization and the ions produced are, for example, protonated molecules: + H⁺. These ions are often relatively stable, tending not to fragment as readily as ions produced by electron ionization.

External links

• American Society for Mass Spectrometry: What other techniques are used to produce ions?

• Chemical Ionization Tutorial

• IUPAC Gold Book Definition (PDF)

• MS Terms Wiki definition

References

• Munson, M.S.B.; Field, F.H. J. Am. Chem. Soc. 1966, 88, 2621-2630. Chemical Ionization Mass Spectrometry. I. General Introduction.

Mass spectrometry | Chemische_Ionisation