Efficient Preparation And Application Of Covalently Bonded Capillary Electrophoresis Coated Columns

With capillary electrophoresis becoming a mainstream separation technology,capillary coatings have become more and more important in capillary electrophoresis.It not only solves the problem of controlling electroosmotic flow and adsorption of macromolecules,but greatly improves the separation efficiency.However,improper selection of coating materials and coating methods will affect the separation effect to different extents,even more serious it will cause the instrument pollution and damage.For these problems,we prepared several simple green capillary coatings and used them to separate several common proteins and actual samples to test their separation performance.The work is summarized as follows:1.By using the self-agglutination of dopamine(DA)to adhere to the inner wall of the capillary,and then connecting hyaluronic acid to form a polydopamine/hyaluronic acid(PDA/HA)capillary coating,the coating column showed good separation performance of the four proteins.2.Synthesis of environmentally friendly,light-sensitive diazoresin(DR)and temperature-sensitive polyethylene glycol diacrylate-dithiothreitol(PEGDA-DTT),and then then applied to the inner wall of the capillary using layer-by-layer self-assembly to form DR/PEGDA-DTT-dithiols coating.The coating has excellent performance in preventing protein adsorption and has a good separation effect on standard protein samples and actual egg white samples.The four-coating capillary column achieves the best separation.In addition,the self-cleaning properties of the coating are its main highlights.3.A dumbbell shaped copolymer of polyethylene oxide-b-polystyrene-b-polyethylene oxide(PEO_x-b-PS-b-PEO_x)was synthesized,and then DR was used as a linker to coat it into the capillary to form a stable covalent bond coating and a good protein separation effect was obtained.And when the grafting segment of PEO is 6,the separation effect is best.4.The internal wall of the capillary was connected with the initiator 2-bromoisobutyric acid(BIBA)by DR,and then combine the 3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate(DMAPS)by atom transfer radical polymerization(ATRP)to form a coating on capillary inner surface directly.The coating can affect the separation effect by controlling the reaction time and obtain good results in protein separation.