| Since the breakthrough of microelectronics in 1960s,miniaturization has become a new trend,made a tremendous impact on all fields of science and technology.In analytical chemistry,miniaturization of chromatographic systems has become a key trend in the field of separation science.As the miniaturization of high performance liquid chromatography(HPLC),Nano-LC has some advantages such as less consumption of solvent and sample,less chromatographic dilution effect and more suitable for coupling with mass spectrometries,these advantages make it widely applied in the fields of biomedicine,food safety and environmental analysis.An important symbol of the miniaturization of liquid chromatography is the miniaturization of chromatographic column,since column is the place where the separation actually take place,and plays an important role in the resolution and selectivity of chromatographic separation,so preparation of high resolution microcolumn is of great importance.Columns applied in the nano-LC systems can be divided into three classes as packed column,monolithic column and open tubular column according to the different morphologies of stationary phase.Among them,packed colunms have some outstanding features such as high column capacity,high separation efficiency,great reproducibility and generally applicability,make it most widely used in the nano-LC field.For a capillary packed column,homogeneous and dense column bed is a necessary condition for the quality assurance,expressing requirements on column packing technologies.Homogeneous,high efficient and well-reproducible columns can be reached via high pressure slurry packing technology at present,but it's not a ideal method for large-scale preparation,and it costs lot of time and effort,so it is desperately needed to improve column packing technologies to get high-resolution and well-reproducible columns in large scale.Chromatographic packing materials are cores of packed colunms,exerts a great effect on the separation performance of colunms,so development and application of novel packing materials is always a hot spot in the field of chromatography.The development of chromatographic packing materials mainly focuses on the size,materials,morphology and stationary phase chemistry of the packings:for the matrix materials,silica matrix chromatographic packings is still dominant,and introduction of hybrid silica materials improved the pH and thermo stability;for the morphology,over 90%of packings are totally porous packings at present,but with the development of core-shell packing mateirals,the dominance of totally porous packings is threatened;for the stationary phase chemistry,reverse-phase packing materials based on the C18 matrix are still in dominance,however,with the rasing requirements on polar compound separation,HILIC packing materials draw reseachers attions guadually.In this article,we explored the application of new chromatographic packing materials(core-shell and HILIC packing materials)on nano-LC,and improved the preparation technologies of capillary colunms and packing materials.This article mainly includes the following parts:In the first chapter,we reviewed the decelopment and application of nano-LC,capillary columns and packing materials,we also introduced and evaluated the preparation technologies of capillary colunms and packing materials,and types of novel chromatographic packing materials.Thus,the purpose and main contents of this article are presented:developed new types of chromatographic packings for nano-LC,improved the packing technology of capillary colunms,and prepare monodisperse chromatography packings via capillary droplet microfluidic technology.In chapter 2,we investigated the performance of core-shell packings in nanoLC,and compared it with totally porous packings.Their chromatographic properties were characterized respectively,and analyzed the differences of their separation performance in the nano-LC mode.They have also been applied in the proteomic analysis of HeLa cells,indicated the potential of core-shell packings in proteomic analysis.In chapter 3,the performance of HILIC packings in nano-LC were investigated,the separation properties of HILIC packings and RPLC packings were compared.HILIC column was also applied in separation of complex protein digests to find the peak capacity of long HILIC columns.In addition,HILIC capillary column was also applied to the proteomics analysis of HeLa cells to explore the potential application of HILIC packings in proteomics analysis.In chapter 4,we developed a new centripetal force packing technology for capillary columns.Via this,we can prepare capillary columns in large scale,and the reliability and repeatability of this technology was evaluated.In addition,we expanded the scope of its application by series and parallel connect capillary columns.Colunms packed by centripetal force were also applied in proteomic analysis of HeLa cells,and their practical application values were proved.In chapter 5,we constructed a droplet microfluidic device based on capillary,and the parameters of the device are optimized to ensure the stable and rapid generation of monodisperse droplets.Then the capillary droplet microfluidic device was applied to prepare monodisperse boronic acid hybrid microspheres,and the enrichment ability of boronic acid hybrid microspheres for small molecular compounds containing cis-dihydroxyl was investigated and applied to glycoprotein enrichment.In chapter 6,the droplet microfluidic device based on capillary was used to prepare chromatographic packings,and ethyl bridged silica microspheres with good monodispersity were prepared.After that,hybrid silica microspheres were modified with C18 functional group to prepare monodisperse reversed-phase chromatographic packings.Firstly,the chemical system of hybrid silica gel microspheres was optimized,and the stability of C18 packings under high temperature and pH was tested.Finally,the separation performance of monodisperse C18 chromatographic packings was characterized. |
PDF Full Text Request