Chemical ionization

Term · Chemistry · MLC-T-CHM-012973

A mass spectrometry ionization method that produces ions through the reaction of analyte molecules with a pre-ionized reagent gas. A large excess of reagent gas, such as methane or ammonia, is first ionized by electron impact, and these primary ions then react with neutral analyte molecules to produce analyte ions via proton transfer or adduction. This gentle process minimizes fragmentation, resulting in mass spectra dominated by the molecular ion or a protonated molecule.

Table 1. Record
Identifier	MLC-T-CHM-012973
Field	Chemistry
Subject	Physical and Biophysical Chemistry
References	Orange Book, 2nd ed., p. 204 (https://media.iupac.org/publications/analytical_compendium/); PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2179 (https://doi.org/10.1351/pac199062112167); PAC, 1991, 63, 1541. 'Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)' on page 1547 (https://doi.org/10.1351/pac199163101541)
See also	Attachment; Chemi-ionization; Electron attachment; Ionization; Proton

Record as JSON

{
  "id": "MLC-T-CHM-012973",
  "term": "Chemical ionization",
  "field": "Chemistry",
  "definition": "A mass spectrometry ionization method that produces ions through the reaction of analyte molecules with a pre-ionized reagent gas. A large excess of reagent gas, such as methane or ammonia, is first ionized by electron impact, and these primary ions then react with neutral analyte molecules to produce analyte ions via proton transfer or adduction. This gentle process minimizes fragmentation, resulting in mass spectra dominated by the molecular ion or a protonated molecule.",
  "subject": "Physical and Biophysical Chemistry",
  "see_also": [
    "attachment",
    "chemi-ionization",
    "electron attachment",
    "ionization",
    "proton"
  ],
  "references": [
    "Orange Book, 2nd ed., p. 204 (https://media.iupac.org/publications/analytical_compendium/)",
    "PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2179 (https://doi.org/10.1351/pac199062112167)",
    "PAC, 1991, 63, 1541. 'Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)' on page 1547 (https://doi.org/10.1351/pac199163101541)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/chemical-ionization/"
}

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