Applications Of Diacetone-D-mannitol-boric Acid Complex In The Enantioseparation And Determination Of Chiral Drugs By NACE

The two enantiomers of ?-agonists are quite different in pharmacodynamics,pharmacokinetics and toxicology.It is of great significance to establish simple and effective methods for their enantioseparation and determination.Capillary electrophoresis(CE)is one of the common methods for the enantioseparation of chiral drugs.Nonaqueous capillary electrophoresis(NACE)is an important branch of CE and has lots of advantages in chiral separation.In this thesis,diacetone-D-mannitol–boric acid complex was in situ synthesized in methanol containing triethylamine.The baseline enantioseparation of seven ?-agonists was achieved in NACE.The formation of diacetone-D-mannitol–boric acid complex was characterized by ultraviolet spectroscopy(UV)and11B-nuclear magnetic resonance spectroscopy(11B-NMR).NACE method was successfully applied to the determination of clenbuterol enantiomers in oral solution and the residual analysis of clenbuterol enantiomers in drinking water and pork livers.The thesis was divided into six chapters.Chapter one,the significance of enantioseparation and determination of ?-agonist was stated.The commonly employed methods for their enantioseparation and determination,and the applications of NACE in enantioseparation were also reviewed.Chapter two,diacetone-D-mannitol–boric acid complex was in situ synthesized in nonaqueous solution and used as a chiral selector in NACE for the enantioseparation of seven?-agonists.In order to achieve a good enantioseparation,the effects of diacetone-D-mannitol,boric acid,and triethylamine concentrations were investigated.Under the optimized conditions,baseline enantioseparation could be obtained for all of the ?-agonists.Among them,six chiral drugs could be resolved within 12 minutes.Chapter three,the formation of diacetone-D-mannitol–boric acid complex was proved by UV and 11B-NMR experiments.Chapter four,the methodological validation of the established NACE method was carried out according to the guidelines of International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use(ICH).The calibration curves of two enantiomers of the five tested drugs showed good linearities with all of the correlation coefficients(r)? 0.9992.Linear range was 1.25~50.00 ?g mL-1.The limits ofdetection(LODs)and the limits of quantification(LOQs)were less than 1.25 ?g mL-1 and5.00 ?g mL-1,respectively.The recoveries were 98.2~101.9% with the relative standard deviation(RSD)less than 0.9%(n=9).The NACE method was successfully applied to the determination of clenbuterol enantiomers in Ambrocol oral solution.Chapter five,combined with selective cation injection technique,the chiral NACE method was applied to the analysis of residues of clenbuterol enantiomers in drinking water and pork liver samples.The results of methodological validation showed that the two enantiomers of clenbuterol have good linearities in the range of 0.25~12.50 ng mL-1,with the correlation coefficients(r)? 0.9984.The LODs and LOQs were 0.05 ng mL-1and 0.25 ng m L-1,respectively.Chapter six: conclusions and outlook.