Cellulose Tris(3,5-Dimethylphenylcarbamate) Regioselectively Bonded to Small Pore Silica Gel as Chiral Stationary Phase for HPLC

2011 ◽  
Vol 117-119 ◽  
pp. 1361-1364
Author(s):  
Yi Jun Zhang ◽  
Cai Xia Dong ◽  
Jun Chen ◽  
Run Qiang Liu

A bifunctional reagent of terephthaloyl chloride was initially adopted as a spacer reagent to prepare the bonded types of chiral stationary phase (CSP) with cellulose derivatives. (3,5-dimethylphenyl)carbamates of cellulose (CDMPC) regioselectively bonded to small pore (3-aminopropyl)silica gel (APS) were prepared with terephthaloyl chloride as a spacer at the 6-position of the primary hydroxyl group on the glucose unit of cellulose. Enantioseparations of five racemic samples are evaluated on the prepared CSP under normal-phase high-performance liquid chromatographic mode with hexane- isopropylalcohol as the mobile phase. The influence of flow rates and mobile phase compositions on the resolution were investigated. The prepared stationary phase was exhibited an effective chiral recognition.

2013 ◽  
Vol 12 (2) ◽  
pp. 108-119 ◽  
Author(s):  
Jakub Moravčík ◽  
Katarína Hroboňová

Abstract 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.


2021 ◽  
Vol 14 (2) ◽  
pp. 98
Author(s):  
Ratih Ratih ◽  
Hermann Wätzig ◽  
Azminah Azminah ◽  
Mufarreh Asmari ◽  
Benjamin Peters ◽  
...  

Chondroitin sulfate A was covalently immobilized onto a monolithic silica epoxy column involving a Schiff base formation in the presence of ethylenediamine as a spacer and evaluated in terms of its selectivity in enantioseparation. The obtained column was utilized as a chiral stationary phase in enantioseparation of amlodipine and verapamil using a mobile phase consisting of 50 mM phosphate buffer pH 3.5 and UV detection. Sample dilution by organic solvents (preferably 25% v/v acetonitrile-aqueous solution) was applied to achieve baseline enantioresolution (Rs > 3.0) of the individual drug models within 7 min, an excellent linearity (R2 = 0.999) and an interday repeatability of 1.1% to 1.8% RSD. The performance of the immobilized column for quantification of racemate in commercial tablets showed a recovery of 86–98% from tablet matrices. Computational modeling by molecular docking was employed to investigate the feasible complexes between enantiomers and the chiral selector.


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