16257 IUPAC Gold Book - phase volume ratio 10.1351/goldbook.16257 16257 current 1 Volume of the mobile phase divided by volume of the stationary phase in a column in counter-current chromatography. The stationary phase volume retention ratio (\(S_{\rm{f}}\)) has been defined as the ratio of the volume of stationary phase (\(V_{\rm{s}}\)) to the total column/coil volume (\(V_{\rm{c}}\)), \(S_{\rm{f}} = V_{\rm{s}}/V_{\rm{c}}\). It is recommended that phase ratio in counter-current chromatography be given the subscript V (i.e. \(\beta_{\rm{V}} = V_{\rm{M}}/V_{\rm{S}}\)) to emphasize phase volume ratio. The \(\beta\) in counter-current chromatography has been defined as the ratio of planetary radius (\(r\)) over main rotor radius (\(R\)), \(\beta = r/R\). counter-current chromatography https://goldbook.iupac.org//terms/view/09887 PAC, 2017, 90, 181. 'Terminology of separation methods (IUPAC Recommendations 2017)' on page 204 (https://doi.org/10.1515/pac-2017-0111) https://goldbook.iupac.org/terms/view/16257/html https://goldbook.iupac.org/terms/view/16257/json https://goldbook.iupac.org/terms/view/16257/plain Citation: 'phase volume ratio' 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.16257 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. 2026-04-18T19:34:33+00:00