{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,26]],"date-time":"2026-04-26T02:55:26Z","timestamp":1777172126384,"version":"3.51.4"},"reference-count":21,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2020,11,17]],"date-time":"2020-11-17T00:00:00Z","timestamp":1605571200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002749","name":"Belgian Federal Science Policy Office","doi-asserted-by":"publisher","award":["Prodex programm"],"award-info":[{"award-number":["Prodex programm"]}],"id":[{"id":"10.13039\/501100002749","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>This study aims at contributing to quinine extraction using supercritical CO2 and ethanol as a co-solvent. The diffusion coefficients of quinine in supercritical CO2 are measured using the Taylor dispersion technique when quinine is pre-dissolved in ethanol. First, the diffusion coefficients of pure ethanol in the supercritical state of CO2 were investigated in order to get a basis for seeing a relative change in the diffusion coefficient with the addition of quinine. We report measurements of the diffusion coefficients of ethanol in scCO2 in the temperature range from 304.3 to 343 K and pressures of 9.5, 10 and 12 MPa. Next, the diffusion coefficients of different amounts of quinine dissolved in ethanol and injected into supercritical CO2 were measured in the same range of temperatures at p = 12 Mpa. At the pressure p = 9.5 MPa, which is close to the critical pressure, the diffusion coefficients were measured at the temperature, T = 343 K, far from the critical value. It was found that the diffusion coefficients are significantly dependent on the amount of quinine in a small range of its content, less than 0.1%. It is quite likely that this behavior is associated with a change in the spatial structure, that is, the formation of clusters or compounds, and a subsequent increase in the molecular weight of the diffusive substance.<\/jats:p>","DOI":"10.3390\/molecules25225372","type":"journal-article","created":{"date-parts":[[2020,11,17]],"date-time":"2020-11-17T07:23:28Z","timestamp":1605597808000},"page":"5372","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Diffusion of Quinine with Ethanol as a Co-Solvent in Supercritical CO2"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7511-2910","authenticated-orcid":false,"given":"Yury","family":"Gaponenko","sequence":"first","affiliation":[{"name":"MRC\u2014Microgravity Research Centre, Universit\u00e9 libre de Bruxelles (ULB), EP-CP165\/62, Avenue F.D. Roosevelt 50, B-1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7787-2865","authenticated-orcid":false,"given":"Aliaksandr","family":"Mialdun","sequence":"additional","affiliation":[{"name":"MRC\u2014Microgravity Research Centre, Universit\u00e9 libre de Bruxelles (ULB), EP-CP165\/62, Avenue F.D. Roosevelt 50, B-1050 Brussels, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6109-5048","authenticated-orcid":false,"given":"Valentina","family":"Shevtsova","sequence":"additional","affiliation":[{"name":"MRC\u2014Microgravity Research Centre, Universit\u00e9 libre de Bruxelles (ULB), EP-CP165\/62, Avenue F.D. Roosevelt 50, B-1050 Brussels, Belgium"},{"name":"Mechanical and Manufacturing Department, Mondragon Goi Eskola Politeknikoa (MGEP), Loramendi 4, Apdo. 23, 20500 Mondragon, Spain"},{"name":"IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1016\/j.ejmech.2015.02.002","article-title":"Quinine conjugates and quinine analogues as potential antimalarial agents","volume":"97","author":"Jones","year":"2015","journal-title":"Eur. J. Med. Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1186\/1475-2875-10-144","article-title":"Quinine, an old anti-malarial drug in a modern world: Role in the treatment of malaria","volume":"10","author":"Achan","year":"2011","journal-title":"Malar. J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"4336","DOI":"10.1021\/acs.analchem.5b04534","article-title":"Carbon Dioxide Expanded Ethanol Extraction: Solubility and Extraction Kinetics of \u03b1-Pinene and cis-Verbenol","volume":"88","author":"Cunico","year":"2016","journal-title":"Anal. Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.supflu.2018.08.012","article-title":"Cosolvent effect of ethanol on the solubility of lutein in supercritical carbon dioxide","volume":"143","author":"Araus","year":"2019","journal-title":"J. Supercrit. Fluids"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"641","DOI":"10.1016\/j.cjche.2016.10.003","article-title":"Measurement and calculation of solubility of quinine in supercritical carbon dioxide","volume":"25","author":"Zabihi","year":"2017","journal-title":"Chin. J. Chem. Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1140\/epje\/i2016-16111-9","article-title":"Development of a high-pressure set-up for measurements of binary diffusion coefficients in supercritical carbon dioxide","volume":"39","author":"Ancherbak","year":"2016","journal-title":"Eur. Phys. J. E"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"475","DOI":"10.1007\/s12217-019-09736-4","article-title":"Near-Critical Behavior of Fick Diffusion Coefficient in Taylor Dispersion Experiments","volume":"31","author":"Gaponenko","year":"2019","journal-title":"Microgravity Sci. Technol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"8466","DOI":"10.1038\/s41598-019-44687-1","article-title":"Diffusion of methane in supercritical carbon dioxide across the Widom line","volume":"9","author":"Ancherbak","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_9","first-page":"329406","article-title":"Infrared Absorption Spectra of Monohydric Alcohols","volume":"2013","author":"Doroshenko","year":"2013","journal-title":"Dataset Pap. Sci."},{"key":"ref_10","unstructured":"(2020, September 02). John Wiley & Sons. Available online: https:\/\/spectrabase.com\/compound\/Ku0ZQJTJi4W."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"43","DOI":"10.5614\/itbj.sci.2011.43.1.4","article-title":"Demethylation of Quinine Using Anhydrous Aluminium Trichloride","volume":"43","author":"Asnawi","year":"2011","journal-title":"ITB J. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1039\/FT9918700597","article-title":"Ternary diffusion coefficients of 18-crown-6 ether-KCl-water by direct least-squares analysis of Taylor dispersion measurements","volume":"87","author":"Leaist","year":"1991","journal-title":"J. Chem. Soc. Faraday Trans."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"104903","DOI":"10.1063\/1.4820357","article-title":"Investigation of Fickian diffusion in the ternary mixture of 1,2,3,4-tetrahydronaphthalene, isobutylbenzene, and dodecane","volume":"139","author":"Mialdun","year":"2013","journal-title":"J. Chem. Phys."},{"key":"ref_14","first-page":"357","article-title":"Measurement and correlation of diffusion coefficients for alcohols in supercritical CO2","volume":"46","author":"Mei","year":"1995","journal-title":"J. Chem. Ind. Eng. (China)"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1016\/j.supflu.2005.10.006","article-title":"Binary diffusion coefficients and retention factors for polar compounds in supercritical carbon dioxide by chromatographic impulse response method","volume":"37","author":"Kong","year":"2006","journal-title":"J. Supercrit. Fluids"},{"key":"ref_16","unstructured":"Lemmon, E.W., Huber, M.L., Bell, I.H., and McLinden, M.O. (2018). NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP, Version 10.0."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Chatwell, R.S., Guevara-Carrion, G., Gaponeneko, Y., Shevtsova, V., and Vrabec, J. (2020). Diffusion of the carbon dioxide-ethanol mixture in the extended critical region. Phys. Chem. Chem. Phys., accepted.","DOI":"10.1039\/D0CP04985A"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"146","DOI":"10.1016\/j.fluid.2007.07.072","article-title":"Tracer diffusion coefficients of benzene in dense CO2 at 313.2 K and 8.5\u201330 MPa","volume":"261","author":"Nishiumi","year":"2007","journal-title":"Fluid Phase Equilib."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1007\/s00217-017-2940-0","article-title":"Possibility of quinine transformation in food products: LC-MS and NMR techniques in analysis of quinine derivatives","volume":"244","author":"Dawidowicz","year":"2018","journal-title":"Eur. Food Res. Technol."},{"key":"ref_20","unstructured":"(2020, November 14). Process for the Preparation of Quinine from Cinchona Bark by Extraction with Supercritical CO2. Available online: https:\/\/patents.google.com\/patent\/DE3704850A1\/en."},{"key":"ref_21","unstructured":"(2020, November 14). Process for Separating and Preparing Quinine Sulfate from Peruvian Bark. Available online: https:\/\/patents.google.com\/patent\/CN102766140A\/en."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/25\/22\/5372\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:34:32Z","timestamp":1760178872000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/25\/22\/5372"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,11,17]]},"references-count":21,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2020,11]]}},"alternative-id":["molecules25225372"],"URL":"https:\/\/doi.org\/10.3390\/molecules25225372","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,11,17]]}}}