The Separation Of Selective Serotonin Reuptake Inhibitors Enantiomers In Capillary Electrophoresis

Capillary electrophoresis (CE) has been one of the subject of numerous investigations in the processing chemical analysis and separation because of its attractive advantages such as fast analysis, high separation efficiency, little consume and so on. In particular, the presence of ionic liquids has been used in separating the chiral substances due to its high conductivity, good solubility, low vapor pressure and no pollution in the past decades. It’s well known that selective serotonin reuptake inhibitors (SSRIs) are mainly used for the treatment of depression, for example fluoxetine, citalopram and venlafaxine. Evidences indicated that the pharmacology and toxicology in the body disparity clearly of SSRIs’enantiomers. Therefore, the separation of drug enantiomers is of vital importance which has a great interesting potential. On the one hand, chiral separations of fluoxetine, and venlafaxine were studied by capillary electrophoresis, β-cyclodextrin (β-CD) as chiral selector, combined with two ionic liquids as the background buffer additives, trimethyl hydroxyethyl ammonium tetrafluoroborate (HOEtN1,1,1BF4) and trimethyl-hydroxyethyl bis (trifluoromethylsulfonyl) imide (HOEtN1,1,1NTF2). Under the optimal conditions, the combination of fluoxetine and venlafaxine enantiomer obviously improved the resolutions, however, the baseline separation haven’t achieved. On the other hand, for fluoxetine, citalopram and venlafaxine enantiomer, carboxymethyl-β-cyclodextrin (CM-β-CD) was chose as another chiral selector, combined with HOEtN1,1,1NTF2 as the background buffer additives. Under the optimal conditions, the resolutions of these enantiomers were achieved above 1.5. It may not be enough to achieve enantiomers separation after CM-β-CD alone. While, after adding ionic liquid(HOEtNl,1,1NTF2), the size of the electroosmosis flow and the effect of stability on the inclusion complex among CM-β-CD and drug enantiomers have changed, which lead to much difference of stability constants between these inclusion complexes, as a result the baseline separation of drug enantiomers have been realized. The above results indicate a new capillary electrophoresis method for chiral separation of the 5-HT reuptake inhibitors, which will be useful in basic reference for simultaneous separation and detection of chiral drugs. Besides, the experimental results show that the ionic liquid was used for the separation of chairl drugs has a potential value in CE.The research and application of graphene oxide is a hot issue in recent years. In the present work, the separation of o-methylaniline and m-methylaniline was studied by capillary electrophoresis, in which the effects of electrophoresis conditions on the resolution. Under the optimal enantioseparation conditions, the baseline separation of o-methylaniline and m-methylaniline was achieved and the resolutions were 2.0. The experimental results indicate that graphene oxide as a new type of stationary phase material has a feasibility and potential application in capillary chromatography. It also provides a new viewpoint for the research of stationary phase in CE, and a fresh idea for the separation of BTEX in sollution.