Title: retardation factor
Long Title: IUPAC Gold Book - retardation factor
DOI: 10.1351/goldbook.R05353
Status: current
Index: quantity

Definition
Ratio of the distance travelled by the centre of the spot to the distance simultaneously travelled by the mobile phase: \[R_{\rm{F}}=\frac{b}{a}\] By definition the \(R_{\rm{F}}\) values are always less than unity. They are usually given to two decimal places. In order to simplify this presentation the \(hR_{\rm{F}}\) values may be used: they correspond to the \(R_{\rm{F}}\) values multiplied by 100. Ideally, \(R_{\rm{F}}\) values are identical to the \(R\) values used in column chromatography.

Related Term
- column chromatography: https://goldbook.iupac.org//terms/view/C01182

Source
- PAC, 1993, 65, 819. 'Nomenclature for chromatography (IUPAC Recommendations 1993)' on page 845 (https://doi.org/10.1351/pac199365040819)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/R05353/html
- json: https://goldbook.iupac.org/terms/view/R05353/json
- xml: https://goldbook.iupac.org/terms/view/R05353/xml

Citation: Citation: 'retardation factor' 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.R05353
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Accessed: 2026-07-13T13:58:46+00:00