Preparation And Application Of Metal-organic Hybrid And Imprinted Polymer Monolith For Microextraction Of Phosphoserine

Protein phosphorylation is an important post-translational modification process,which plays an important role in the regulation of eukaryotic cell growth,differentiation,signal transmission,etc.It also has an impact on regulation of hormones,production of disease,and adaptation of irritation.It is critical to the activity of life.Phosphorylation of serine,the most ubiquitous process in protein phosphorylation,plays an important role in changing the conformation of protein structure,which can make the enzyme activation or inactivation,and alter the function of cell by mediating the interaction of the protein recognition.Understanding the mechanism of phosphorylated serine（P-Ser）on organisms has significance in research of disease and the development of drugs.Before analysis of phosphorylated substances,the study of P-Ser in biological samples is vital.However,the organism is complex and biological sample contains various proteins and amino acids,the detection of P-Ser should be greatly interfered.Hence,the quantitative analysis of P-Ser is a huge challenge.In this paper,molecular imprinting technology and modification of metal-organic hybrid polymer were applied to synthesize complex monolith for effective P-Ser extraction from biological samples,which improved sensitivity of HPLC-ESI-MS/MS.This paper includes the following two parts:（1）P-Ser molecularly imprinted polymer monolithic column was synthesised in the pipet tip using P-Ser as template,acrylamide as functional monomer,methanol and water as the solvent.The effects of the amount of methanol and water on polymerization were investigated.The materials were characterized using infrared spectrum,scanning electron microscopy,thermogravimetric analysis and nitrogen adsorption method.The selectivity of monolithic column was explored.The derivative method of P-Ser was optimized.Under the optimized extraction conditions,an SPME-HPLC-MS/MS method for the determination of P-Ser in pork liver samples was established and applied.The LOD was 2.5 ng g^-1,the recoveries were between 95.5%and 100.4%with RSDs were less than 4.4%,and it was proved that it could be used for the actual sample analysis.（2）Under the optimized synthesis conditions,organic-inorganic hybrid polymer monolithic column was synthesized in the pipet tip.Metal-organic hybrid polymer was synthesized on the pore surface of the polymer through the layer-by-layer self-assembly method.It was used as SPME medium in conjunction with HPLC-MS/MS.In the polymer monolithic column,methylacrylic acid（MAA）was used as functional monomer which could coordinate with metal ion.Using infrared spectrum,scanning electron microscopy（SEM）,XPS spectra,nitrogen adsorption method to characterize the structure and properties of the material.The extraction conditions was optimized.The SPME-HPLC-ESI-MS/MS method was used to pork liver samples of P-Ser sensitive detection.The LOD was 2.2 ng g^-1,the recoveries were between 93.6%and 104.0%with RSDs were less than 5.7%.