Application of Cinchona alkaloid-based zwitterionic chiral stationary phases in supercritical fluid chromatography for the enantioseparation of Nα-protected proteinogenic amino acids

Gyula Lajkó, István Ilisz, Gábor Tóth, Ferenc Fülöp, Wolfgang Lindner, Antal Péter

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Stereoselective supercritical fluid chromatographic separations of the enantiomers of a large set of Nα-Fmoc proteinogenic amino acids were carried out on the recently developed Cinchona alkaloid-based zwitterionic chiral stationary phases Chiralpak ZWIX(+)™ and ZWIX(-)™ with protic solvents as co-solvents. The effects of the mobile phase composition, the natures and concentrations of the acid or base additives, the co- and counter-ions and temperature on the separations were investigated. The retention time in most cases slightly increased, while the separation factor decreased with increasing temperature. The changes in standard enthalpy, δ(δH°), entropy, δ(δS°), and free energy, δ(δG°), were calculated from the linear van't Hoff plots derived from the lnα vs 1/T curves in the studied temperature range (20-60°C). The values of the thermodynamic parameters depended on the natures of the selectors and the structures of the analytes. On both ZWIX(+)™ and ZWIX(-)™ columns, enthalpically-driven separations were observed. The elution sequence was determined in all cases and was observed to be opposite on ZWIX(+)™ and ZWIX(-)™ which acted for the presented applications as chiral anion exchanger.

Original languageEnglish
Pages (from-to)134-145
Number of pages12
JournalJournal of Chromatography A
Volume1415
DOIs
Publication statusPublished - Oct 9 2015

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Keywords

  • Enantiomer separation
  • N-Fmoc-protected proteinogenic amino acids
  • Supercritical fluid chromatography
  • Temperature effect
  • Zwitterionic chiral stationary phases

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Organic Chemistry

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