02503 IUPAC Gold Book - fraction extracted 10.1351/goldbook.F02503 F02503 current synonym: recovery factor quantity 1 The fraction of the total quantity of a substance extracted (usually by the solvent) under specified conditions, i.e. \(E_{\rm{A}} = \frac{Q_{\rm{A}}}{Q_{\rm{A}}^{'}}\) where \(Q_{\rm{A}}\) is the mass of A extracted and \(Q_{\rm{A}}^{'}\) is the total mass of A present at the start. \(E\) may be expressed as a percentage, \(\% \, E\). The term extractability is qualitative and should not be used as a synonym for fraction extracted. If the aqueous phase is extracted with \(n\) successive portions of solvent, the phase volume ratio (solvent/feed) being \(r\) each time, the fraction extracted is given by: \[E_{n} = 1 - \left ( rD + 1 \right )^{-n}\] If \(n = r = 1\) and \(E_{1} = \frac{D}{1+D}\) this expression is a concept of value in chromatography theory. The fraction extracted is also known as the recovery factor, especially for a multistage process. chromatography https://goldbook.iupac.org//terms/view/C01075 recovery https://goldbook.iupac.org//terms/view/R05206 PAC, 1993, 65, 2373. 'Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations 1993)' on page 2384 (https://doi.org/10.1351/pac199365112373) https://goldbook.iupac.org/terms/view/F02503/html https://goldbook.iupac.org/terms/view/F02503/json https://goldbook.iupac.org/terms/view/F02503/plain Citation: 'fraction extracted' 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.F02503 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. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . 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. 2026-04-19T05:41:36+00:00