HIGH – PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR ENANTIOSEPARATION OF UNDERIVATIZED α-AMINO ACIDS USING CYCLOFRUCTAN – BASED CHIRAL STATIONARY PHASES
Keywords:amino acids, cyclofructan – based chiral selectors, HPLC, thermodynamic study
Chromatographic columns with chiral stationary phases based on chemically - bonded derivatized cyclofructans were evaluated for HPLC enantioresolution of underivatized α-amino acids. The analytical study of chiral separation of these analytes was focused on the selection of suitable chiral stationary phase and mobile phase. Using isopropyl carbamate cyclofructan 6 as a chiral stationary phase, α- amino acid optical isomers were separated. The retention and enantioseparation of chiral amino acids were also influenced by a mobile phase composition. The mixture methanol/acetonitrile/acetic acid/triethylamine (75/25/0.3/0.2 v/v/v/v) was found to be the most effective mobile phase for HPLC separation of studied compounds. HPLC enantioresolution of chiral amino acids was thermodynamically studied. Based on the enthalpy and entropy contribution values calculated from the van´t Hoff equation, HPLC enantioseparation under chosen chromatographic conditions was found to be an enthalpically driven.