Synthesis And Separation Characteristics Of Epoxy Resin-based Molecularly Imprinted Polymer Monoliths

The novel epoxy resin-based monolithic polymer materials are prepared from epoxy resin (EP), amine, polyethylene glycol (PEG) by in-situ step-addition polymerization. Two epoxy resin-based polymer monolithic materials are prepared with molecular imprinting technique (MIT), and the polymers are employed to enrich and separate residual pesticides and heavy metal ions. Two analysis and detection methods are established with high performance liquid chromatography (HPLC) and inductively coupled plasma atomic emission spectrometry (ICP-AES). A novel epoxy resin-based polymer monolithic column is prepared by in situ polymerization as stationary phase of HPLC to analyze the compounds, and the chromatographic separate performance is also observed.A novel molecular imprinted polymer (MIPs) monolithic column is prepared from epoxy resin, diethlenetriamine (DETA), pore-forming reagent (PEG^-1540) and malachite green (MG) as template molecules by in-situ step-addition polymerization. The MIPs are employed to adsorb MG from solutions.and detection with HPLC. The morphology of the resulting MIPs monolithic column has been characterized by FT-IR and scanning electron microscopy (SEM). The porosity is 76.8%. It's 96% of MG is adsorbed on the MIPs when pure water or acetonitrile are used as loading solutions under 40?C. The recovery of MG removed from the MIPs is from 99.6% to 115% when HAc/NH4Ac (0.125 mol·L^-1, pH=4.5): acetonitrile (3:7, V/V) is employed as eluting solution. MG, LMG, MV and CV are employed for selectivity tests. The results show that the MIPs are specificity and selectivity for rebinding to MG. 10 mL of tap water spiked with MG at the concentration of 20 to 500 ng mL?1. The relative standard deviation (RSD) of MIPs for MG extraction is in the range of 4.443–14.487%, and the recoveries are found to be 95.15–100.25%, indicating the feasibility for extract MG from the sample.A novel Cd (II) imprinted polymers is prepared from epoxy resin, diethlenetriamine-thiourea as curing agent, PEG^-1540 as pore-forming reagent and Cd (II) as template molecules by in-situ step-addition polymerization. And then the polymers are employed to adsorb trace metal ions from solutions and detection with ICP-AES. The adsorption conditions including pH, temperature, time, adsorption selectivity, the maximum adsorption, elution conditions, precision and accuracy are detailed study. The results show that the trace Cd²⁺can be quantitatively enriched at pH 6.0-7.0 in 24 hours under 60?C. The amount of Cd²⁺ adsorb per unit mass of the Cd(II) imprinted polymers increased with the initial concentration of the Cd²⁺ till the average maximum adsorption capacity is obtained. The maximum static adsorption capacities of the Cd (II) imprinted polymers is 136.58μmol·g^-1. Moreover, the Cd (II) imprinted polymers can be suitably used as adsorbent for target ions in the presence of competitor species. The recovery of Cd²⁺ is 98.6% when 0.1mol·L^-1 EDTA was employed as eluting solution.A novel epoxy resin-based polymer monolithic column is prepared from PEG^-1540, epoxy resin, diethlenetriamine with the mass ratio is 8:4:1 in the stainless steel chromatographic columns (50mm×4.6mm i.d). The column has large through-pores and hydroxyls had been characterized by scanning electron microscopy and FT-IR. The chromatographic performance on the monolithic column is evaluated. Rapid separation of nicotinamide and nicotinic acid is achieved with 100% pure water as mobile phase in 2.0min at flow rate of 1.0mL·min^-1. The resolution is 0.83. The molecular imprinted polymer monolithic materials possess several advantages including low-cost, simple and convenient preparation, storage stability, repeated operations without lose activity, high mechanical strength, durability to heat and pressure, and applicability in harsh chemical media. It's helpful to extend the application fields of the molecular imprinting technique and the monolithic column separate technique.