Preparation Of Novel Organic Polymer Monolithic Columns And Their Applications In The Assay Of Small Molecular Compounds

In this dissertation,two novel organic polymer high-performance liquid monolithic columns and a graphene oxide-doped organic polymer monolithic column were prepared.Two novel high performance liquid chromatographic methods for efficient,rapid and simple separation of small molecular compounds were developed by using the prepared novel organic polymer monolithic column as stationary phases.A monolithic column doped with graphene oxide was used as a solid phase microextraction adsorbent to enrich sulfonamides.The main research work is as follows:(1)A porous monolithic column was prepared by in situ free-radical polymerization in a stainless steel column(4.6 mm i.d.×100 mm).The polymerization reacted using 1,6-hexylene dimethacrylate as a single monomer,methanol and1-dodecanol as the binary porogens and 2,2-azobisisobutyronitrile as an initiator.The ratio of monomer to porogen was optimized by scanning electron microscopy,permeability,and chromatographic performance of separation of phenol,naphthol,biphenyl,and phenanthrene.The poly(HDDMA)monolith column prepared under the optimal conditions was characterized by infrared spectroscopy,scanning electron microscopy,stability and reproducibility.The results showed the poly(HDDMA)monolith column had good stability and permeability in the mobile phase flow rate of4 mL/min.It was used as stationary phase of high-performance liquid chromatography to seperate three kinds of small molecular compounds(phenol,aromatic hydrocarbon,benzoic acid).These three kinds of small molecular compounds can be successfully separated by optimizing the flow rate and composition of the mobile phase.The separation mechanism may be hydrophobic interaction.(2)A polymer monolithic column was prepared by using 1,6-hexanediol dimethacrylate(HDDMA)and trimethylolpropane triacrylate(TMPTA)as common monomers.The ability to separate benzene,biphenyl,phenanthrene,permeability and chromatographic performance were used as indicators to optimize the ratio between the two monomers and the porogen system.The monolithic column under optimal preparation conditions was characterized by infrared spectroscopy,scanning electron microscopy,stability,reproducibility.The results showed the poly(HDDMA-TMPTA)monolith column had good stability and permeability when the mobile phase flow rate was 2 mL/min.The aromatic compounds were successfully separated using poly(HDDMA-TMPTA)as high-performance liquid phase stationary phase.However,the separations of phenols and benzoic acids were not ideal.(3)A graphene oxide-doped trimethylolpropane triacrylate monolith column in a pipette tip was prepared.The selection of monomers,selection of porogen system,and the amount of graphene oxide was optimized by single rotation method.The graphene oxide-doped trimethylolpropane triacrylate monolithic column was characterized by infrared spectroscopy and scanning electron microscopy.The results showed the monolithic column was successfully prepared.The response surface methodology was used to optimize the extraction process and successfully enriched the eight sulfonamides in the water samples.Sulfonamides had good linearity in the range of10-160?g/L,R~2 both reach 0.99,and the detection limit was 0.93-5?g/L,which can achieve the enrichment detection of trace sulfonamides in complex samples.