Preparation And Evaluation Of Hybrid Modified Capillary Monolithic Column

Polymer based hybrid monolith is a multifunctional stationary phase which is prepared with functional particles and polymer matrix.It combined the advantage both from monolith,including uniform matrix,excellent reproducibility,easily preparation and low cost,and advantage from the functional particles.Separation ability got improved by incorporating the functional particles in polymer monolith.Preparation scheme can be divided into three types:physical doping method,chemical bond method and post-modification method.In this paper,we used all above methods hybrid modified monolith preparation.In the first part of thesis,an efficient method to prepare polymer monoliths with incorporated carbon nanotubes in a mixture of RTILs and DESs was developed.With assistance of the binary green solvent,RTILs and DESs,SWCNTs were dispersed successfully in pre-polymerization mixture without need of oxidative cutting of CNTs.Compared with the monolith made without SWCNTs,the monolith with the incorporation of s SWCNTs exhibited high column efficiency（251,000 plates/m）in the chromatographic separation.The morphology of the monolith can be tuned by the composition of mixture of RTILs and DESs to afford good column permeability and excellent separation ability for small molecules of alkyl phenones and alkyl benzenes.In the second part of thesis,a new lanthanide metal-organic frameworks NKU-1have successfully incorporated into poly（BMA-coEDMA）monolith.Lanthanide metal-organic frameworks[Eu₂（ABTC）_1.5（H2O）₃（DMA）]（NKU-1）which were synthesized by self-assembly of Eu（III）and 3,3,5,5-azo benzene tetracarboxylic acid have been fabricated into poly（BMA-co-EDMA）monoliths.RTILs and DMF were developed as binary porogen obtaining homogeneous dispersibility for NKU-1 and high permeability for monolithic column.The successful incorporation of NKU-1into poly（BMA-co-EDMA）was confirmed and characterized by FT-IR spectra,SEM,TEM,X-ray diffraction,EDS.Separation ability of the result monoliths was demonstrated by separating four groups analytes in CEC,including alkylbenzenes,polycyclic aromatic hydrocarbon,aniline series and naphthyl substitutes.Compared with bare monolith（column efficiency of 100,000 plates/m）,NKU-1-poly（BMA-co-EDMA）monoliths displayed greater column efficiency（maximum 210,000plates/m）and higher permeability,as well as less peak tailing.In the third part of thesis,a hybrid monolith incorporated with mesoporous molecular sieve MCM-41 of uniform pore structure and high surface area was prepared with binary green porogens for the first time.With RTILs and DESs as porogens,silylation modified MCM-41-MPS was incorporated into poly（BMA-co-EDMA）monoliths covalently.Because of,High permeability and homogeneity for the resultant hybrid monolithic columns was achieved owing to dispersibility offered by green solvent system.The result monolith was characterized by SEM,TEM,EDS area scanning,FT-IR spectra and nitrogen adsorption tests.Chromatographic performance of result monolith was characterized by separating small molecules in CEC,including phenol series,naphthyl substitutes,aniline series and alkyl benzenes.The maximum column efficiency of MCM-41-MPS grafted monolith reached 209,000 plates/m,which was twice higher than the MCM-41-MPS free monolith.Moreover,successful separation of non-steroidal anti-inflammatory drugs and polycyclic aromatic hydrocarbons demonstrated the capacity in broad-spectrum application of the MCM-41-MPS incorporated monolith.In the fourth part of thesis,we prepared maltose modified hydrophilic monolithic column by post-polymerization modification method.The maltose modified HILIC column was tested by polar compound group,phenolic compound,nucleic acid and nucleoside group.Comparing with the precursor monolithic column,MALT modified HILIC column exhibited improved chromatography performance,as well as decreased EOF.The change was based on the hydroxyl rich property of MALT.Besides,the prepared MALT modified column also applied in chiral separation of hexobarbital and warfarin.