Application of Cinchona alkaloid-based zwitterionic chiral stationary phases in supercritical fluid chromatography for the enantioseparation of N-alpha-protected proteinogenic amino acids
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 a...
Elmentve itt :
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| Dokumentumtípus: | Cikk |
| Megjelent: |
2015
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| Sorozat: | JOURNAL OF CHROMATOGRAPHY A
1415 |
| doi: | 10.1016/j.chroma.2015.08.058 |
| mtmt: | 2958870 |
| Online Access: | http://publicatio.bibl.u-szeged.hu/8111 |
| Tartalmi kivonat: | 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. (C) 2015 Elsevier B.V. All rights reserved. |
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| Terjedelem/Fizikai jellemzők: | 134-145 |
| ISSN: | 0021-9673 |