title: Micellar electrokinetic chromatography with polyelectrolyte complexes as micellar pseudo-stationary phases.
abstract: The separation of dansyl (DNS-AAs) and carbobenzoxy (CBZ-AAs) amino acids using micellar electrokinetic chromatography employing polyelectrolyte-surfactant complexes (PSC) formed in the reaction between polyacrylic acid (PAA) and dodecyltrimethylammonium bromide (DTAB) as pseudo-stationary phases was described. The PSCs were stabilized by hydrophobic interactions of alkyl chains of the surfactant ions and converted to an intramolecular micellar-like phase. The running buffer was a 50mM solution of sodium phosphate (pH 6.0) containing 4.6-20.2mM PSC, in which a part of carboxyl groups of PAA was blocked by aliphatic amines. For the systems with 7.9mM of PAA/DTAB complex (phi=0.30, phi-composition of water-soluble polyelectrolyte complex) as a pseudo-stationary phase, the peaks of six dansyl amino acids (DNS-AAs) were baseline resolved. The separation in this case is based on a complex distribution mechanism of the dansyl derivatives between the free buffer and the intramolecular micellar-like phase of the water-soluble PSC. On the other hand, the additives of PAA/DTAB complex (phi=0.30) to the running buffer does not essentially affect on the electrophoretic behaviour of the CBZ-AAs, the variant MEKC is not realized. The influence of the concentration of the complex of PAA/DTAB on the electrophoretic behaviour of analytes was investigated. Relative retentions and relative selectivities were used for describing electrophoretic behaviour of the amino acid derivatives.
authors.affiliation: Chemistry Department, Moscow State University, GSP-2 Vorob'evy Hills, 119992 Moscow, Russia. shpak@analyt.chem.msu.ru
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Shpak
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Pirogov
authors.forename: Oleg A
authors.initials: OA
authors.lastname: Shpigun
mesh_terms: D000465:Algorithms; D000596:Amino Acids / Q000737:chemistry; D002021:Buffers; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D003619:Dansyl Compounds / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D008823:Micelles; D011108:Polymers / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D000596:Amino Acids; D002021:Buffers; D003619:Dansyl Compounds; D004573:Electrolytes; D007202:Indicators and Reagents; D008823:Micelles; D011108:Polymers; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; C013912:decyltrimethylammonium