Title: | Interactions of basic compounds with ionic liquids used as oils in microemulsion liquid chromatography |
Author(s): | Pankajkumar-Patel N; Peris-Garcia E; Ruiz-Angel MJ; Garcia-Alvarez-Coque MC; |
Address: | "Departament de Quimica Analitica, Universitat de Valencia, c/Dr. Moliner 50, Burjassot, Spain. Departament de Quimica Analitica, Universitat de Valencia, c/Dr. Moliner 50, Burjassot, Spain. Electronic address: celia.garcia@uv.es" |
DOI: | 10.1016/j.chroma.2022.463142 |
ISSN/ISBN: | 1873-3778 (Electronic) 0021-9673 (Linking) |
Abstract: | "Aqueous microemulsions (MEs), where an oil coexists with water in the presence of the anionic surfactant sodium dodecyl sulphate (SDS), have been proposed as a solution to decrease the amount of organic solvent in the mobile phase needed in reversed-phase liquid chromatography (RPLC). However, the oil phase of a typical ME is volatile, toxic and flammable, and although it is added in a small amount, it would be desirable to avoid it from an environmental perspective. This is the reason for the proposal of Peng et al. (J. Chromatogr. A 1499 (2017) 132?ªª139) to replace the oil in microemulsion liquid chromatography (MELC) by the apolar ionic liquid (IL) 1-hexyl-3-methylimidazolium hexafluorophosphate ([C(6)C(1)IM][PF(6)]), to analyse neutral phenolic acids at acidic pH. Based on this report, an MELC procedure is here proposed for beta-adrenoceptor antagonists, which are basic compounds where the dominant species is cationic. To verify the formation of MEs containing SDS and IL, and elucidate the interactions between the cationic basic compounds with the SDS anion, and the cation and anion in the IL, an extensive study was carried out with several methylimidazolium ILs containing the cations [C(2)C(1)IM](+), [C(4)C(1)IM](+), or [C(6)C(1)IM](+), combined with the anions Cl(-), BF(4)(-), or PF(6)(-), using 1-butanol as co-surfactant. The behaviour was compared with that observed in classical MELC with octane, micellar liquid chromatography with SDS and 1-propanol, and RPLC with mobile phases containing an IL and acetonitrile" |
Keywords: | "Anions Chromatography, Liquid/methods *Ionic Liquids/chemistry Oils Surface-Active Agents/chemistry Water/chemistry Ionic liquids Oil-in-water microemulsion liquid chromatography Sodium dodecyl sulphate beta-adrenoceptor antagonists;" |
Notes: | "MedlinePankajkumar-Patel, N Peris-Garcia, E Ruiz-Angel, M J Garcia-Alvarez-Coque, M C eng Netherlands 2022/05/23 J Chromatogr A. 2022 Jul 5; 1674:463142. doi: 10.1016/j.chroma.2022.463142. Epub 2022 May 13" |