Preparation Of Tolazoline And Naphazoline Imprinted Polymeric Microspheres And Application In Solid-Phase Extraction

The development,characteristics,principle,methodology and application of molecular imprinting technique were reviewed.And the advance in analytical methods of tolazoline and naphazoline were summarized.The thesis of this paper was preparation,characterization and application of molecularly imprinted polymer(MIP) with tolazoline and naphazoline as template molecule,respectively,prepared via aqueous suspension polymerization,multi-step swelling polymerization and precipitation polymerization.Scanning election microscope(SEM) and nitrogen sorption analyzer were used to analyze properties of the products.The adsorption properties and imprinting efficiency of MIP were studied through batch tests with ultraviolet spectrum,gas chromatography and high performance liquid chromatography.The experimental sections were divided into three chapters.The main results of the studies as follows:1.Preparation,characteristics and application of molecularly imprinted polymeric microspheres for tolazoline by aqueous suspension polymerizationMIP using tolazoline as target molecule were synthesized by aqueous suspension polymerization.From SEM,microspheres of MIP were 50-200μm.The adsorption properties of MIP and nonimprinted polymer(NIP) were invstigated by static rebinding tests.The maximum static adsorption capacities of the MIP and NIP for tolazoline were 95.28 and 52.66μmol g^-1,respectively, which indicted that MIP has a significantly higher binding capacity for tolazoline than NIP.The competitive tests with similarly structural naphazoline as competitor were performed to evaluate the recogenition capability of MIP for template imprinting efficiency.MIP presented a considerable selectivity to tolazoline with the separate factor up to 1.75,while they were used as sorbent of solid phase extraction(SPE).Finally,the SPE coupled to gas chromatography(GC) was applied to detected tolazoline in human urine samples with recoveries of 99-114%and RSDs of 1.5-2.5%.2.Preparation,characteristics and application of molecularly imprinted polymeric microspheres for tolazoline by multi-step swelling polymerizationBased on the previous work,MIP for tolazoline were synthesized by a different method of multi-step swelling polymerization.The obtained materials were characterized by SEM,nitrogen adsorption.The static adsorption experiments were performed to evaluate adsorption capability of MIP and NIP with the results for tolazoline was 78.9 and 38.8μmol g^-1,respectively,indicating that MIP had a significantly higher binding capacity for tolazoline than that of the NIP.MIP was used as stationary phase of SPE,and the relative selectivity coefficient(k') was 5.21,showing that MIP had higher selectivity for tolazoline than NIP.The SPE was applied to extract tolazoline from urine samples with recovery 105.9%,and it was compared with C₈-SPE with recovery 86.9%.The method of SPE-GC was applied to the determination of tolazoline in urine samples.MIP showed a promising potential for SPE of tolazoline in urine samples.3.Selective solid-phase extraction of naphazoline using imprinted polymeric microspheres as matrix prepared by precipitation polymerizationConsidering residual emulsifier or stabilizer remaining on the surfaces of the particles,leading to impair selective rebinding of MIP-sorbent to the template molecules,MIPs using naphazoline as template was prepared by precipitation polymerization with narrow size distribution between 0.5-1.0μm,which was easier and more time-saving than the former method.The effects of dispersive solvents dichloromethane(DCM),acetonitrile(ACN) and Methanol(MeOH) on partical size and morphology of MIPs(P1,P2 and P3) were investigated by SEM.The selectivity of P1,compared with NIP,C₈ and C₁₈ were evaluated via static adsorption.The results showed that the bond amount of P1 for naphazoline was significantly higher than other sorbents.P1 were applied as stationary phase of SPE to extract naphazoline from nasal drops.The recovery was more than 89%(RSD＜5%) obtained by high performance liquid chromatograph.In addition,cloud point extraction(CPE) is an extraction and preconcentraction technique based on phase separation in aqueous nonionic surfactant solution,which is a favorable alternative to traditional organic solvent extraction.The history,concept,principle and application in analysis of CPE were reviewed.CPE was primitively enmployed to enrich astemizoline from serum,and then detected.