Term: peak widths
https://doi.org/10.1351/goldbook.P04466

Definition:
Peak widths represent retention dimensions (time or volume) parallel to the baseline. If the baseline is not parallel to the axis representing time or volume, then the peak widths are to be drawn parallel to this axis. Three peak-width values are commonly used in chromatography. Peak width at base (w b) is the segment of the peak base intercepted by the tangents drawn to the inflection points on either side of the peak. Peak width at half height (w h) is the length of the line parallel to the peak base at 50% of the peak height that terminates at the intersection with the two limbs of the peak. Peak width at inflection points (w i) is the length of the line drawn between the inflection points parallel to the peak base. The peak width at base may be called the 'base width'. However, the peak width at half height must never be called the 'half width' because that has a completely different meaning. Also, the symbol w 1 / 2 should never be used instead of w h.

Related Terms:
1) chromatography (http://doi.org/10.1351/goldbook.C01075).

Source: Orange Book, 2nd ed., p. 101 (https://media.iupac.org/publications/analytical_compendium/)

Citation: 'peak widths' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.P04466

License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.

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.