Titel
Comparison of the Separation Performances of Cinchona Alkaloid-Based Zwitterionic Stationary Phases in the Enantioseparation of β2- and β3-Amino Acids
Autor*in
István Ilisz
Department of Inorganic and Analytical Chemistry, University of Szeged
Autor*in
Nóra Grecsó
Department of Inorganic and Analytical Chemistry, University of Szeged
Autor*in
Aleksandra Misicka
Department of Chemistry, University of Warsaw
... show all
Abstract
The enantiomers of twelve unusual β2- and β3-homoamino acids containing the same side-chains were separated on chiral stationary phases containing a quinine- or quinidine-based zwitterionic ion-exchanger as chiral selector. The effects of the mobile phase composition, the nature and concentration of the acid and base additives and temperature on the separations were investigated. The changes in standard enthalpy, ∆(∆H°), entropy, ∆(∆S°), and free energy, ∆(∆G°), were calculated from the linear van’t Hoff plots derived from the ln α vs. 1/T curves in the studied temperature range (10–50 °C). The values of the thermodynamic parameters depended on the nature of the selectors, the structures of the analytes, and the positions of the substituents on the analytes. A comparison of the zwitterionic stationary phases revealed that the quinidine-based ZWIX(−)™ column exhibited much better selectivity for both β2- and β3-amino acids than the quinine-based ZWIX(+)™ column, and the separation performances of both the ZWIX(+)™ and ZWIX(−)™ columns were better for β2-amino acids. The elution sequence was determined in some cases and was observed to be R < S and S < R on the ZWIX(+)™ and ZWIX(−)™ columns, respectively.
Stichwort
column liquid chromatographyβ2-amino acidsβ3-amino acidsCinchona alkaloid-based chiral stationary phases
Objekt-Typ
Sprache
Englisch [eng]
Persistent identifier
https://phaidra.univie.ac.at/o:448394
Erschienen in
Titel
Molecules
Band
20
Ausgabe
1
Seitenanfang
70
Seitenende
87
Verlag
MDPI AG
Erscheinungsdatum
2014
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