Unusual temperature-induced retention behavior of constrained ß-amino acid enantiomers on the zwitterionic chiral stationary phases ZWIX(+) and ZWIX(-).
Chirality
; 26(8): 385-93, 2014 Aug.
Article
em En
| MEDLINE
| ID: mdl-24839210
ABSTRACT
The effects of temperature on the chiral recognition of cyclic ß-amino acid enantiomers on zwitterionic [Chiralpak ZWIX(+) and ZWIX(-)] chiral stationary phases were investigated. Experiments were performed at different mobile phase compositions and under 10°C column temperature increments in the temperature range 10-50°C. Apparent thermodynamic parameters and T(iso) values were calculated from plots of ln k and ln α versus 1/T, respectively. Unusual temperature behavior was observed, especially on the ZWIX(-) column, where the application of MeOH/MeCN (50/50 v/v) containing 25 mM triethylamine and 50 mM formic acid as mobile phase led to nonlinear van't Hoff plots and increasing retention time with increasing temperature. On both columns, both enthalpically and entropically driven separations were observed.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Temperatura
/
Aminoácidos
Idioma:
En
Revista:
Chirality
Assunto da revista:
BIOLOGIA MOLECULAR
/
QUIMICA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Hungria
País de publicação:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
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US
/
USA