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

作者：Lajko Gyula; Ilisz Istvan; Toth Gabor; Fueloep Ferenc; Lindner Wolfgang; Peter Antal^*

来源：Journal of Chromatography A, 2015, 1415: 134-145.

DOI：10.1016/j.chroma.2015.08.058

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

Stereoselective supercritical fluid chromatographic separations of the enantiomers of a large set of 1 4Fmoc proteinogenic amino acids were carried out on the recently developed Cinchona alkaloid-based zwitterionic chiral stationary phases Chiralpak ZWIX(+)(TM) and ZWIX(-)(TM) with protic solvents as cosolvents. 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, Delta(Delta H degrees), entropy, Delta(Delta S degrees), and free energy, Delta(Delta G degrees), were calculated from the linear van't Hoff plots derived from the Ina vs 1/T curves in the studied temperature range (20-60 degrees C). The values of the thermodynamic parameters depended on the natures of the selectors and the structures of the analytes. On both ZWIX(+)(TM) and ZWIX(-)(TM) columns, enthalpically-driven separations were observed. The elution sequence was determined in all cases and was observed to be opposite on ZWIX(+)(TM) and ZWIX(-)(TM) which acted for the presented applications as chiral anion exchanger.

• 出版日期2015-10-9
• 单位河北医科大学