Title: base peak
Long Title: IUPAC Gold Book - base peak
DOI: 10.1351/goldbook.B00608
Status: current

Definition
The peak in a mass spectrum corresponding to the separated ion beam which has the greatest intensity. This term may be applied to the spectra of pure substances or mixtures.

Related Term
- mass spectrum: https://goldbook.iupac.org/terms/view/M03749

Sources
- Orange Book, 2nd ed., p. 206 (https://media.iupac.org/publications/analytical_compendium/)
- 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 1554 (https://doi.org/10.1351/pac199163101541)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/B00608/html
- json: https://goldbook.iupac.org/terms/view/B00608/json
- xml: https://goldbook.iupac.org/terms/view/B00608/xml

Citation: Citation: 'base peak' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.B00608
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Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-08-09T19:30:31+00:00