title: Hexafluoroisopropanol-modified cetyltrimethylammonium bromide/sodium dodecyl sulfate vesicles as a pseudostationary phase in electrokinetic chromatography.
abstract: A novel catanionic surfactant vesicle system, formulated from hexafluoroisopropanol (HFIP), cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS), was developed as pseudostationary phase (PSP) in electrokinetic chromatography (EKC). HFIP, as an organic modifier with the prominent properties of ionization, hydrogen bond donor and hydrophobicity, was used to effectively promote the spontaneous vesicle formation from CTAB/SDS mixed aqueous solutions, where precipitates are easy to occur due to long carbon chains, and adjust the performance of CTAB/SDS vesicles. The physical features (size and viscosity) and electrophoretic parameters (electroosmotic mobility, electrophoretic mobility and elution range) of HFIP-modified CTAB/SDS vesicles were characterized as HFIP volume content (0-4%, v/v), CTAB/SDS molar ratio (2:8-7:3mol/mol) and total surfactant concentration (10-50mM) varying, respectively. The 3% v/v HFIP-modified CTAB/SDS (3:7mol/mol, 50mM) vesicle system proves to have the largest mean diameter (288.20nm) and the widest elution range (12.41), which is also much wider than that of the corresponding other four PSP systems including trifluoroethanol (TFE)-modified CTAB/SDS vesicles (5.69), isopropanol-modified CTAB/SDS micelles (2.03), HFIP-modified SDS micelles (4.86) and unmodified SDS micelles (3.12). The chromatographic performance of the HFIP-modified vesicle system was evaluated by separating eight polycyclic aromatic hydrocarbons, nitrotoluene positional isomers, five positively charged and five negatively charged/neutral drugs, respectively. Baseline or near-baseline separation was achieved for each series of solutes. Compared with the TFE-modified vesicle system, as well as the HFIP-modified and unmodified SDS micelle systems, the HFIP-modified vesicle system shows the best separation selectivity, the highest or comparable efficiency, and the lowest retention.
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071 China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071 China.
authors.forename: Yunfang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071 China.
authors.forename: Jie
authors.initials: J
authors.lastname: Mei
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071 China.
authors.forename: Bin
authors.initials: B
authors.lastname: Deng
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071 China. Electronic address: yuxiuxiao2011@whu.edu.cn.
authors.forename: Yuxiu
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D020374:Chromatography, Micellar Electrokinetic Capillary; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D020005:Propanols / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D012996:Solutions; D014783:Viscosity; D006845:Hydrocarbons, Fluorinated
chemical_list: D000077286:Cetrimonium; D002593:Cetrimonium Compounds; D020005:Propanols; D012967:Sodium Dodecyl Sulfate; D012996:Solutions; C001337:hexafluoroisopropanol; D006845:Hydrocarbons, Fluorinated
keywords: Cetyltrimethylammonium bromide; Electrokinetic chromatography; Hexafluoroisopropanol; Pseudostationary phase; Sodium dodecyl sulfate; Vesicle