MilliporeSigma
  • Structural and temperature effects on enantiomer separations of bicyclo[2.2.2]octane-based 3-amino-2-carboxylic acids on cinchona alkaloid-based zwitterionic chiral stationary phases.

Structural and temperature effects on enantiomer separations of bicyclo[2.2.2]octane-based 3-amino-2-carboxylic acids on cinchona alkaloid-based zwitterionic chiral stationary phases.

Journal of pharmaceutical and biomedical analysis (2014-06-09)
István Ilisz, Nóra Grecsó, Márta Palkó, Ferenc Fülöp, Wolfgang Lindner, Antal Péter
ABSTRACT

Procedures for the direct high-performance liquid chromatographic enantiomer separation of four bicyclo[2.2.2]octane-based 3-amino-2-carboxylic acids were developed in polar-ionic mode on zwitterionic chiral stationary phases (CSPs) based on cinchonane alkaloide quinine, quinidine and chiral sulfonic acid motifs. The effects of the mobile phase composition including the type of acid and base additives, the structures of the analytes and temperature were investigated. Experiments were performed at constant mobile phase compositions in the temperature range 10-50°C in order to study the effects of temperature, and thermodynamic parameters were calculated from plots of ln k or ln α vs. 1/T. Some mechanistic aspects of the chiral recognition process are discussed with respect to the structures of the analytes. It was found that the enantiomeric separations were in most cases enthalpically driven, but entropically driven separation was also observed. The sequence of elution of the enantiomers on the pseudo-enantiomerically behaving CSPs was determined in all cases.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Triethylamine, ≥99.5%
Sigma-Aldrich
Triethylamine, ≥99%
Sigma-Aldrich
Triethylamine, for amino acid analysis, ≥99.5% (GC)
Sigma-Aldrich
Triethylamine, puriss. p.a., ≥99.5% (GC)
Sigma-Aldrich
Ethylamine, 97%
Sigma-Aldrich
Triethylamine, for protein sequence analysis, ampule, ≥99.5% (GC)
Sigma-Aldrich
Propylamine, 98%
Sigma-Aldrich
Propylamine, purum, ≥99.0% (GC)
Sigma-Aldrich
Triethylamine, BioUltra, ≥99.5% (GC)
Sigma-Aldrich
Acetonitrile solution, contains 10.0% acetone, 0.05% formic acid, 40.0% 2-propanol
Sigma-Aldrich
Ethylamine, 99.0%
Supelco
Residual Solvent - Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Formic acid, ACS reagent, ≥96%
Sigma-Aldrich
Formic acid, puriss., meets analytical specifications of DAC, FCC, 98.0-100%
Supelco
Propylamine, analytical standard
Supelco
Triethylamine, analytical standard
Sigma-Aldrich
Formic acid, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥98%
Sigma-Aldrich
Formic acid, reagent grade, ≥95%
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (v/v) trifluoroacetic acid
Sigma-Aldrich
Acetic acid-12C2, 99.9 atom % 12C
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
Sigma-Aldrich
Acetonitrile solution, contains 0.05 % (w/v) ammonium formate, 5 % (v/v) water, 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
Formic acid, ≥95%, FCC, FG
Sigma-Aldrich
Acetic acid, natural, ≥99.5%, FG
Sigma-Aldrich
Acetic acid, ≥99.5%, FCC, FG
Sigma-Aldrich
Triethylamine, ≥99.5%
Sigma-Aldrich
Propylamine, ≥99%
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) formic acid, suitable for HPLC
Supelco
Acetonitrile, analytical standard
Sigma-Aldrich
Diethylamine, puriss. p.a., ≥99.5% (GC)