title: Using nonrandom two-liquid model for solvent system selection in counter-current chromatography.
abstract: Selection of an appropriate solvent system is of great importance for a successful counter-current chromatography separation. In this work, the nonrandom two-liquid (NRTL) model, a thermodynamic method, was used for predicting the partition coefficient based on a few measured partition coefficients. The NRTL method provides quite satisfactory results for model solutes in first correlating measured partition coefficient in a few representative biphasic liquid systems and then successfully predicting partition coefficient in other two-phase liquid systems. According to the predicted partition coefficient, a suitable solvent system can be screened. Assisted with the NRTL method, the solvent system composed of hexane/ethyl acetate/methanol/water (1:4:1:4, v/v) was rapidly screened for the successful separation of two major compounds with high purity from Malus hupehensis leaves. The results demonstrated that the NRTL model can offer a simple and practical strategy to estimate partition coefficients in support of CCC solvent system selection, which will significantly minimize the experimental efforts and cost involved in solvent system selection.
authors.affiliation: College of Chemistry and Chemical engineering, Central South University, Changsha 410083, China.
authors.forename: Da-Bing
authors.initials: DB
authors.lastname: Ren
authors.affiliation: College of Chemistry and Chemical engineering, Central South University, Changsha 410083, China.
authors.forename: Yan-Hua
authors.initials: YH
authors.lastname: Qin
authors.affiliation: College of Chemistry and Chemical engineering, Central South University, Changsha 410083, China.
authors.forename: Yong-Huan
authors.initials: YH
authors.lastname: Yun
authors.affiliation: College of Chemistry and Chemical engineering, Central South University, Changsha 410083, China.
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Lu
authors.affiliation: College of Chemistry and Chemical engineering, Central South University, Changsha 410083, China.
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Chen
authors.affiliation: College of Chemistry and Chemical engineering, Central South University, Changsha 410083, China. Electronic address: yizeng_liang@263.net.
authors.forename: Yi-Zeng
authors.initials: YZ
authors.lastname: Liang
mesh_terms: D000085:Acetates / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D003377:Countercurrent Distribution / Q000295:instrumentation / Q000379:methods*; D006586:Hexanes / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D000085:Acetates; D006586:Hexanes; D012997:Solvents; D014867:Water; C026385:n-hexane; C007650:ethyl acetate; D000432:Methanol
keywords: Counter-current chromatography; Malus hupehensis; NRTL model; Prediction of partition coefficient; Solvent system selection