Title: resolution: peak width definition
Long Title: IUPAC Gold Book - resolution: peak width definition
DOI: 10.1351/goldbook.12554
Status: current

Definition
For a single peak corresponding to singly charged ions at mass \(m\) in a mass spectrum, the resolution may be expressed as \((m/z)/\Delta(m/z)\), where \(\Delta(m/z)\) is the width of the peak at a height which is a specified fraction of the maximum peak height. It is recommended that one of three values 50, 5, or \(\pu{0.5\%}\) should always be used.

Note
For an isolated symmetrical peak recorded with a system which is linear in the range between \(\pu{5\%}\) and \(\pu{10\%}\) levels of the peak, the \(\pu{5\%}\) peak width definition is equivalent to the \(\pu{10\%}\) valley definition. A common standard is the definition of resolution based upon \(\Delta m\) being full width of the peak at half its maximum (FWHM) height.

Related Term
- resolution: 10 per cent valley definition: https://goldbook.iupac.org//terms/view/12553

Source
- PAC, 2013, 85, 1515. 'Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)' on page 1585 (https://doi.org/10.1351/PAC-REC-06-04-06)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/12554/html
- json: https://goldbook.iupac.org/terms/view/12554/json
- xml: https://goldbook.iupac.org/terms/view/12554/xml

Citation: Citation: 'resolution: peak width definition' 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.12554
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Accessed: 2026-07-26T05:00:32+00:00