Study On Methyltestosterone Imprinted Polymers And Its Application In Solid Phase Extraction

Molecular imprinting technique (MIT) is a kind of rising technique for dividing molecules, it's often described as a way of making a molecular lock to match a molecular key. The polymers which have a high affinity and selectivity to the imprinted molecules can be prepared. MIT is developing quickly these years. It has been reported recently that molecularly imprinted polymers have a good foreground applied in solid phase extraction, enzyme-mimicking catalyzer, chemical-bionic sensor and so on.The paper consists of four chapters as follows:1. This chapter summarizes the development of the preparation and application of molecularly imprinted polymers (MIP), analyses the issue and offers an insight in the near future.2. A methyltestosterone-imprinted polymer was prepared using bulk polymerization through a molecular imprinting technology, with MAA as functional monomer and EGDMA as cross-linker. The physical properties were characterized by means of SEM and BET. The affinity of the MIP as HPLC solid phase for the template and its structural analogs was studied. The influence of the mobile phase using different volume fractions of water in the acetonitrile on the retention behavior was also discussed. In addition, equilibrium binding experiments were carried out to evaluate the adsorption properties and selective recognition ability of the MIP. The results showed that, the stronger polarity of the the mobile phase was, the weaker recognition ability of the MIP to the template was. The maximal apparent adsorptive capacity has reached 8.8567μmol/g, and the ability of recognition reached 5.34, thus exhibited selectivity and recognition ability to the template.3. Further application of the above MIP was explored. MT-SPE columns were prepared using dry and wet method, respectively. Then the washing solution and eluting solution were optimized after the standard methyltestosterone solution in acetonitrile as loaded. The recoveries were calculated separately, and the two methods were generally compared. The results showed that, the filling of MT-SPE using wet MIP exhibited better uniformity. So the recovery was 96.72%, otherwise, the recovery using dry MIP was 85.02%. Moreover, the recovery was still above 90% after using 15 times. As a result, MIP-SPE exhibited high stability and durability.4. A methyltestosterone-imprinted polymer was prepared using precipitation polymerization, with MAA as functional monomer and EGDMA as cross-linker. The physical properties were characterized by means of SEM and BET. The influences of polymerization methods, the solvent volume and the initiate on the formation of microspheres was studied. In addition, equilibrium binding experiments were carried out to evaluate and compare the adsorption properties and selective recognition ability of the MIPs. The results showed that the particle size of the microspheres would reach a largest limiting point (about 1.7μm) when the ratio of the template to the solvent is 1:500 (mmol:mL). Moreover, the MIPs using precipitation polymerization exhibited highest selectivity and recognition ability to the template when the ratio of the template to the solvent is 1:200 (mmol:mL). The maximal apparent adsorptive capacity has reached 44.1643μmol/g, and the specific separation ability has also reached 22.28. In addition, the physical properties, the adsorption properties and selective recognition ability of the MIPs, which were separately prepared using bulk polymerization and precipitation polymerization were also investigated in the paper.