| Chiral purity plays a significant role in the interest of pharmaceuticals, agrochemical and foods since one of enantiomers usually exhibits therapeutic activity while the other isomer has no activity or even probably demonstrates adverse effects. Enantiomers often differ from each other in the way they rotate plane-polarized light and in their behavior in a chiral environment. Chiral recognition may be performed in direct or indirect methods. The enantioseparation on chiral stationary phases (CSPs) in HPLC represents one of the most facile and direct methods. To date, chemically bonded CSPs using cyclodextrins (CDs) have receive prominent attention due to their utility and stability with various solvents. In this paper, the "click" immobilized perphenylcarbamated β-cyclodextrin stationary phases was filled into the column for HPLC application, then evaluated the performance of the chromatographic column under normal phase (NP), revered phase (RP) and polar organic phase (PO). Besides, both of CCP (per-phenylcarbamated β-CD) and CCC (per-3-chloro-4-methylperphenylcarbamated β-CD) were studied to separate 40 chiral drugs, by contrast, it found that the electron-withdrawing group-Cl and an electron-donating groups-CH3 has a great influence on the chiral separation. The thesis contains three parts: (1) Evaluation of CCP under reversed phase in high performance liquid chromatography.First, we evaluated the limit of detection, relative standard deviations, linearity of the column, which proved that the column has good repeatability and reproducibility. Then the chiral recognition of the columns was explored with 26 chiral compounds including aryl alcohols, flavanoids and adrenergic drugs in reversed phase high performance liquid chromatography. The flow rate, column temperature, the content and composition of the organic phase, the pH and concentration of the buffer and other aspects were studied to optimize the results, moreover, the structure of the compounds also had a great influence on the resolution.(2) Evaluation of CCP under normal phase in high performance liquid chromatography. Firstly, the parameters for the separations of aryl alcohols, flavanoids and adrenergic drugs were determined using CCP as chiral stationary phase. Then in binary system, we discoveried the composition of polar mobile phase had effect on separation results. Then we added methanol to the binary system, the resolution of some chiral drugs have been improved under ternary system of normal phase. Finally, the chiral separation of flavonoids in polar organic phase was also investigated. The pure methanol, ethanol, n-propanol, isopropanol and acetonitrile were used as mobile phase, the preferential order for chiral resolution was methanol>ethanol>isopropanol> n-propanol> acetonitrile.(3) Comparing of different resolution between CCP and CCC. For the enantiomeric separation of a group of 40 compounds including aryl alcohols, flavonoids, adrenergic drugs, Fmoc-amino acid, hypoglycemic agents and other commonly used chiral drugs used CCP and CCC under normal phase and polar organic phase. It proved that CCC has better performance in separating chiral drugs. Besides, we investigated the influence of mobile phase composition, separation temperature and chiral selector on the enantiomer elution order (EEO), and the results of CCP computer simulations were consistent with the obtained findings under reversed phase conditions. Finally, the effects of different chromatographic conditions on the peak profiles were studied.In summary, the cyclodextrin chiral stationary phases have good separated performance under three modes. This research offers a support for enantioseparation of racemics and a plateform for designing novel CD CSPs. |
PDF Full Text Request