Preparation Of Novel Restricted Access Media-Molecularly Imprinted Nanomaterials Materials And Application Of Their Separation And Enrichment In Real Samples

Restricted access media-molecularly imprinted polymers nanomaterials(RAM-MIPs)are widely used as adsorbents for solid phase extraction due to their predictability and specificity.The adsorbent can extract small molecules and exclude biological macromolecules,greatly simplifying the sample pretreatment process,and it has fast adsorption rate,good selectivity,large adsorption capacity,good hydrophilicity,easy elution,easy operation,and economical It has the advantages of time green and is widely used in chromatographic analysis,food and other fields.In this study,silica(Si O₂)microspheres,metal organic frameworks(MOFs)and magnetic silica(Fe₃O₄@Si O₂)microspheres were used as substrates,and surface-initiated atom transfer radical polymerization(SI-ATRP)was used to prepare It is able to selectively separate and detect target analytes from biological samples with restricted access molecularly imprinted polymers and to analyze and detect the residues of nucleosides,gatifloxacin and chloramphenicol in samples method.1.Preparation of a RAM-MIPs for selective adsorption of N₄-acetylcytidinePeople often study the nucleosides in human urine as possible biomedical markers for cancer,acquired immunodeficiency syndrome(AIDS)and systemic RNA conversion.A method has been developed to quickly separate and enrich normal and modified nucleosides in urine with good resolution.Here we have prepared N₄-acetylcytidine molecularly imprinted polymers(NRAMIPs)on the surface of silica gel.The maximum adsorption capacity of N4-acetylcytidine is 79.98 mg/g,and the protein elimination rate is 99.16%.The adsorption equilibrium is reached within 25 min.A solid phase extraction column filled with NRAMIPs was used to selectively enrich and analyze N4-acetylcytidine from human urine samples.The recovery rate was 77.6-101.9%,and the relative standard deviation was 2.6-4.3%(n=3).The detection limit(S/N=3)is 8.4?g/L.The linear range of N₄-acetylcytidine is 2.4-6.7 mg/L,and the correlation coefficient is 0.996.The results show that the method has been successfully applied to urine samples.2.Preparation and application of a new type of gatifloxacin restricted access molecular imprinting materialsA new type of restricted access molecularly imprinted nanomaterial was successfully prepared on MOFs by SI-ATRP technology.Then it was used as a solid phase extraction material,and the quinolone in the bovine serum was detected and analyzed by HPLC.NH₂-MIL-125@RAMIPs is considered to be an adsorbent for gatifloxacin.The resulting material has a good binding capacity(86.1 mg/g)and fast binding kinetics(36 min).The results show that the prepared NH₂-MIL-125@RAMIPs have excellent specific recognition ability to GTFX.Combined with high performance liquid chromatography,the SPE column packed with NH₂-MIL-125@RAMIPs was used to selectively enrich GTFX antibiotics from bovine serum.The recovery rate of GTFX is between 96.8-105.6%and the relative standard deviation is 1.7-3.2%(n=3).The detection limit(S/N=3)is 10.5?g/L.The research results show that this method has been successfully applied to the selective enrichment of GTFX in bovine serum.It provides a simple and effective method for the direct detection of GTFX in bovine serum.3.Preparation and application of chloramphenicol magnetic restricted access molecularly imprinted polymerThis experiment introduces an efficient method for the simultaneous determination of chloramphenicol.The chloramphenicol magnetic limited-entry imprinted polymer was prepared based on the bifunctional monomer method,and the sample was pretreated with solid phase extraction(SPE)and high performance liquid chromatography(HPLC)was used for detection.We characterized and studied the surface morphology and adsorption properties of the polymer.The experimental results showed that the maximum adsorption capacity of chloramphenicol was 95.08 mg/g,and the protein rejection rate was 99.4%.The adsorption equilibrium is reached within 19 minutes.A solid phase extraction column filled with CAP-RAM-MMIPs was used to selectively enrich and analyze chloramphenicol antibiotics from bovine serum.The recovery rate was 95.6-106.2%,and the relative standard deviation was 2.0-4.1%(n=3).The detection limit(S/N=3)is 11.4?g/L.These results indicate that CAP-RAM-MMIPs are highly effective pretreatment adsorbents for biological sample analysis.