Polydopamine Coating Doped with Graphene Oxide Enhances Enantioseparation of Capillary Column

How to improve the enantiomer separation efficiency of drugs is a hot topic. In this paper, polydopamine (PDA) coating doped with graphene oxide (GO) by physical adsorption was used to modify the capillary column to enhance the enantioseparation efficiency of the drugs. In the capillary electrochromatography (CEC) system, the novel capillary column with carboxymethyl-β-cyclodextrin (CM-β-CD) as a chiral selector has completed the enantioseparation of four basic drugs (propranolol, metoprolol, amlodipine and chlorpheniramine). The optimum separation conditions were obtained by optimizing the pH of the buffer, the concentration of organic modifier, the concentration of the chiral selector and the voltage, and the resolution and peak shape were significantly improved compared with uncoated bare-fused column. The stability and reproducibility of the new capillary column were satisfactory and the relative standard deviation of intra-day and inter-day was <3.2%, and of column-to-column was <4.8%. The rich functional groups of GO are key factors to improve the enantioseparation efficiency, which also indicates that nanomaterials with easy modification of functional groups and large specific surface area are excellent resources for capillary modification applications.