title: Dansyl amino acid enantiomer separation on a teicoplanin chiral stationary phase: effect of eluent pH.
abstract: The retention and separation of a series of D,L dansyl amino acids (used as test solutes) on a teicoplanin stationary phase were investigated over a wide range of mobile phase (citrate buffer-methanol, 90:10, v/v) pH. An approach based on the development of various equilibria was carried out in order to describe the retention behavior of the solute in the chromatographic system. The equilibrium constants corresponding to the transfer of the anionic and zwitterionic forms of the dansyl amino acids from the mobile to the stationary phase were determined. These values allowed one to explain the decrease in the retention factor and the associated increase in the separation factor as the eluent pH was increased. Thermodynamic parameter variations were calculated so that the driving forces of the solute association with the teicoplanin phase were derived. This approach indicated that the chiral discrimination was principally controlled by the interaction between the anionic form of the solute and the stationary phase.
authors.affiliation: Laboratoire de Chimie Analytique, Faculté de Pharmacie, Domaine de la Merci, La Tronche, France. eric.peyrin@ujf-grenoble.fr
authors.forename: E
authors.initials: E
authors.lastname: Peyri
authors.forename: C
authors.initials: C
authors.lastname: Ravelet
authors.forename: E
authors.initials: E
authors.lastname: Nicolle
authors.forename: A
authors.initials: A
authors.lastname: Villet
authors.forename: C
authors.initials: C
authors.lastname: Grosset
authors.forename: A
authors.initials: A
authors.lastname: Ravel
authors.forename: J
authors.initials: J
authors.lastname: Alary
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D003619:Dansyl Compounds / Q000737:chemistry / Q000302:isolation & purification*; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007477:Ions; D013237:Stereoisomerism; D017334:Teicoplanin; D013816:Thermodynamics
chemical_list: D000596:Amino Acids; D003619:Dansyl Compounds; D007202:Indicators and Reagents; D007477:Ions; C033853:dansyl acid; D017334:Teicoplanin