Dissertation > Excellent graduate degree dissertation topics show

Separation of Pharmaceutical Enantiomers by Ligand Exchange Method Based on Chiral Ionic Liquids

Author: LiJing
Tutor: JiangXinYu
School: Central South University
Course: Analytical Chemistry
Keywords: Ligand exchange chiral ionic liquids Chiral separation Phenylalanine enantiomers Ofloxacine enantiomers Mandelic acidenantiomers
CLC: O658
Type: Master's thesis
Year: 2013
Downloads: 13
Quote: 0
Read: Download Dissertation

Abstract


In the past decades, With the research of the chiral substance and the importance of chiral molecules for use in production of pharmaceuticals and food products, considerable optical pure enantiomers were demanded. Chromatography especially the high performance liquid chromatography is the most active method. The chiral ligand exchange chromatography is a simple, effective and widely used mean of separation and accurate analytical methods for determination of enantiomeric purity. The chiral ligand exchange chromatography has several advantages that can be used in a normal column and the analysis cost is low. The chiral separation can be obtained by changing the selectors, the concentration of selectors and the composition of the mobile phase.Based on ligand exchange mechanism, ofloxacine (OFLX) enantiomers were successfully separated using [C4mim][Pro] as a chiral ligand coordinated with copper(Ⅱ), Separation conditions were optimized, where4mmol/L [C4mim][Pro] and3mmol/L Cu+were dissolved in methanol/water (20:80, v/v) with pH5.2at a flow rate of0.8mL/min. Based on the mechanism of ligand exchange, chiral ionic liquids was used to separate three substances as the following:Based on ligand exchange mechanism, phenylalanine enantiomers were successfully separated using [C4mim][Pro] as a chiral ligand coordinated with copper(Ⅱ), Under this conditions, the Phe enantiomers could be baseline separated effectively. And some thermodynamical parameters were evaluated. In the range of25±45℃, the values of△△H0and△△S0were both negative, and|△△H0>|T△△S0|, which showed that the chiral separation of Phe enantiomers was an enthalpy-controlled process. And the values of△H0of D-Phe were larger than those of L-Phe, indicating that L-Phe had stronger affinity to the stationary phase, which was consistent with the elution order of monomers.Based on the chiral ligand exchange mechanism, the liquid-liquid extraction method in the chiral ionic liquid/ethyl acetate system was used to separate the mandelic acid enantiomers. In this system, the role of chiral ionic liquid are solvent and extractant. The influcing factors such as the length of the alkyl chain of the chiral ionic liquids, chiral ionic liquids concentration, copper ion concentration, the concentration of racemic were studied. The optimal conditions were ethyl acetate as organic solvent, MA concentration of20mg/ml, ionic liquids [HMIM][L-Pro], the molar ratio of AAIL and copper ion of2:1, the extraction time of2.5min, extraction temperature of30℃with the enantioselectivity of1.53.

Related Dissertations

  1. Synthesis and Resolution Property of N-(9-Fluorenylmethoxycarbonyl)-D-Tryptophan and D-Phenylalanine Imprinted Polymer,O631.3
  2. Chiral Resolution of Naproxen by Lipase in Water-miscible Organic-solvents,TQ463
  3. Extraction of water-soluble drug enantiomers β- cyclodextrin reaction,TQ460.1
  4. Study on Separation and Analysis of Chiral Drugs by Capillary Electrophoresis,O657.8
  5. Study on Preparation of Ligand Exchange Flocculant and Its Performance of Defluoridation,TU991.2
  6. Synthesis of Functional Ionic Liquids and Their Applications in High-performance Liquid Chromatography,O657.72
  7. Preparation of Silica-based Chromatographic Microcolumns and Detection of Melamine in Milk Powder,TS252.7
  8. The cellulose derivatives film preparation and separation of chiral compounds,TB383.2
  9. The Synthesis and Chiral Separation of Fluoxetine Intermediate,TQ463
  10. The Preparation of Levamlodipine Besylate and Its Tablet,TQ460.4
  11. Preparation and Application of monosaccharide , disaccharide , trisaccharides chiral stationary phase high performance liquid chromatography,O629.1
  12. The Study of the New Type Cycoldextrin Derivatives Applied in CE,O658.9
  13. Chiral Resolution Applied Research of Four Racemic Pesticides on CHIRALPAK AS-H Chiral Column by High Performance Liquid Chromatography,S48
  14. Investigation the Resolution of Chiral Drugs by Capillary Electrophoresis and High Performance Liquid Chromatography,R917
  15. Extraction and Analysis of Allantion in Department of Wheat Crops,TQ914.1
  16. Study on the Enantiomer Separation of Three Chiral Pesticides and Its Stereoselective Environmental Behavior,TQ450.2
  17. The Application of Helical Poly(4,4,4-triphenyl-1-butene Oxide) in Gas Chromotography and the Synthesis of Triphenyl-substituted Conjugated Dienes,O657.7
  18. Preparation of L-menthol by Biocatalyzed Diastereoselective Resolution,O621.2
  19. The Synthesis of Chiral Ionic Liquids and the Reasearch of Chiral Ionic Liquids as Chiral Recognition Agent for the Chiral Resolution of Tryptophan,O621.2
  20. Lipase Immobilized on Magnetic Muti-Walled-Carbon Nanotubes Catalyzed Resolution of α-Phenylethanol,R914
  21. Explanation of Enantioseparation of Amino Acid Derivatives in Gas Chromatography and the Mechanism of Supermolecular Compounds of Cyclodextrins and Chloamphenicol,TQ461

CLC: > Mathematical sciences and chemical > Chemistry > Analytical Chemistry > Separation of elements and compounds
© 2012 www.DissertationTopic.Net  Mobile