Preparation And Application Of Polydopamine/β-cyclodextrin Coated Capillary Column For Electrochromatography

It is well known that two enantiomers of chiral drugs may exhibit different biological,pharmacodynamic and pharmacokinetic properties due to the specific enantioselective interactions with enzymes,receptors or other biological macromolecules.So,the separation and analysis of chiral drugs plays an increasingly important role.Currently,capillary electrochromatography is one of the main separation methods for enantiomers of chiral drugs,it has the advantages of high separation efficiency,good selectivity,fast analysis speed,less consumption and low cost.In this work,an open tubular capillary electrochromatography column was prepared by immobilizingβ-cyclodextrin on the inner wall of pre-treated capillary via non-covalent adsorption of polydopamine.In addition,the chiral separation performance of the preprated column was investigated by separating proton pump inhibitors and amino acid enantiomers.1.A chiral open tubular capillary electrochromatography column withβ-cyclodextrin as a stationary phase was prepared via non-covalent adsorption of polydopamine,and the column preparation conditions were optimized.The coating solution was 5.0 mg/m L dopamine and 10.0 mg/m Lβ-cyclodextrin,the coating time was 2 h.Moreover,the results of infrared spectroscopy,scanning electron microscopy and electroosmotic flow indicated that the polydopamine/β-cyclodextrin coating was successfully immobilized on the inner wall of pre-treated capillary.2.The polydopamine/β-cyclodextrin coated open tubular capillary electrochromatography column was used for chiral separation and analysis of five proton pump inhibitors,including lansoprazole,pantoprazole,tenatoprazole,omeprazole and rabeprazole.The influences of type,p H and concentration of buffer solution,separation voltage on enantioseparation were further investigated.Under the separation condition of 100mmol/L Tris-H₃PO₄buffer solution（p H 5.0）and separation voltage of 15 k V,the enantiomers of lansoprazole,pantoprazole,tenatoprazole,omeprazole and rabeprazole were fully resolved within 15 min with high resolutions of 4.57 to 8.13.The method was extensively validated in terms of accuracy,precision and linearity and proved to be robust.Good linear relationships were obtained for the enantiomers of five proton pump inhibitors between mass concentration and peak area in a certain range,and the correlation coefficients were less than 0.9928.The limit of quantitation and limit of detection were less than 17μg/m L and 5.1μg/m L,respectively.The recovery rates were in the range of 84.2%-115.2%.The method was reliable,simple and rapid,and provided a reference for the content determination and quality control of proton pump inhibitor drugs.3.The polydopamine/β-cyclodextrin coated open tubular capillary electrochromatography column was used for chiral separation and analysis of D,L-tyrosine and D,L-phenylalanine.The influences of type,p H and concentration of buffer solution,separation voltage and organic additive on enantioseparation were further investigated.Under the separation condition of 40 mmol/L sodium citrate solution（p H 5.5）and separation voltage of 15 k V,the resolutions of D,L-tyrosine and D,L-phenylalanine were 1.69 and 1.53,respectively,and the migration times were less than 20 min.The prepared column showed good chiral separation efficiency.