title: Multivariable optimization of the micellar system for the ionic liquid-modified MEKC separation of phenolic acids.
abstract: An ionic liquid (IL)-modified micellar electrokinetic chromatography (MEKC) method was proposed for the separation and determination of eight phenolic acids. In order to increase separation efficiency and selectivity, the micelle system consisting of aqueous mixtures of ILs, Tween 20 and borate was optimized using a D-optimal design. A 16-run experimental plan was carried out. The results indicated that the addition of ILs in background electrolyte could significantly alter the electrophoretic behavior and improve the resolution of target analytes. By evaluating the electropherograms obtained, a satisfactory separation condition for all analytes was achieved in 10min with optimized buffer composed of 0.70% (w/w) 1-butyl-3-methylimidazolium tetrafluoroborate, 8.1% (w/w) polyoxyethylene sorbitan monolaurate (Tween 20) and 10mM sodium borate at pH 9.2. Under these conditions, all calibration curves showed good linearity (r(2)>0.9969), and accuracy (recoveries ranging from 94.71 to 106.85%). Finally, the proposed method was successfully applied to determine the phenolic acids in a Chinese medicine compound, compound danshen dripping pills.
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China.
authors.forename: Chao-Ran
authors.initials: CR
authors.lastname: Li
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China. Electronic address: liping2004@126.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, No. 24 Tongjia Lane, Nanjing 210009, China. Electronic address: 104yang104@163.com.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
mesh_terms: D001881:Borates / Q000737:chemistry; D002138:Calibration; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D062385:Hydroxybenzoates / Q000032:analysis*; D052578:Ionic Liquids / Q000737:chemistry*; D008823:Micelles; D011136:Polysorbates / Q000737:chemistry
chemical_list: D001881:Borates; D004365:Drugs, Chinese Herbal; D062385:Hydroxybenzoates; D052578:Ionic Liquids; D008823:Micelles; D011136:Polysorbates; C010634:sodium borate; C017616:phenolic acid
keywords: Additives; Ionic liquids; Micellar electrokinetic chromatography; Mixture design; Phenolic acids