{"term":{"id":"09946","title":"multilayer coil","longtitle":"IUPAC Gold Book - multilayer coil","doi":"10.1351\/goldbook.09946","code":"09946","status":"current","definitions":[{"id":1,"text":"Separation column used for high-speed counter-current chromatography.","notes":{"1":"The multilayer coil is prepared from a long piece of polytetrafluoroethylene (PTFE) tubing by coaxially winding it around a spool-shaped holder, making multiple coiled layers.","2":"Usually, three different inner diameter sizes of tubing are used: ca. \\(\\pu{1 mm}\\) for analytical, \\(\\pu{1.6 mm}\\) for semipreparative, and \\(\\pu{2.6 mm}\\) for preparative separations. It provides efficient mixing of the two phases and a high retention of the stationary phase under a high flow rate of the mobile phase."},"contexts":[],"links":[{"term":"high-speed counter-current chromatography","url":"https:\/\/goldbook.iupac.org\/terms\/view\/09944"}],"sources":["PAC, 2017, 90, 181. 'Terminology of separation methods (IUPAC Recommendations 2017)' on page 204 (https:\/\/doi.org\/10.1515\/pac-2017-0111)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/09946\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/09946\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/09946\/plain"},"citation":"Citation: 'multilayer coil' 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.09946","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.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","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.","accessed":"2026-08-10T04:02:59+00:00"}}