title: Separation of hydrophobic solutes by organic-solvent-based micellar electrokinetic chromatography using cation surfactants.
abstract: In this study, the separation of 13 homologous stick-like hydrophobic solutes, i.e., biphenyl nitrile derivatives, by organic-solvent-based micellar electrokinetic chromatography (MEKC) was investigated in terms of separation medium composition, species and concentration of surfactant, other additives, separation voltage and temperature. The results showed that the 13 strong hydrophobic compounds were baseline separated in 25 min with a repeatability of less than 1.3% (RSD) for migration time. The separation medium was a mixture of methanol, 2-propanol and water (58.5:10:31.5), containing 150 mM cetyltrimethylammonium bromide (CTAB) and 20 mM sodium borate. Variety of solvent composition, temperature and applied voltage all showed remarkable effect on the separation. The organic-solvent-based MEKC method proved to be superior to the aqueous MEKC and microemulsion electrokinetic chromatography (MEEKC) methods for the separation of strongly hydrophobic compounds.
authors.affiliation: The Key Lab of Bioorganic Chemistry and Molecular Engineering, Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Suxuan
authors.initials: S
authors.lastname: Gong
authors.forename: Fujia
authors.initials: F
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.forename: Chunjin
authors.initials: C
authors.lastname: Gao
authors.forename: Yiping
authors.initials: Y
authors.lastname: Liao
authors.forename: Huwei
authors.initials: H
authors.lastname: Liu
mesh_terms: D002412:Cations; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D009930:Organic Chemicals / Q000737:chemistry*; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature
chemical_list: D002412:Cations; D009930:Organic Chemicals; D012997:Solvents; D013501:Surface-Active Agents