| In present work,ED-MIL-101 was used as carrier and geniposide,quercetin and caffeic acid as template molecules to prepare molecularly imprinted polymers.The structure of MIPs was characterized by using SEM and FTIR method and so on.The adsorption behavior of this molecularly imprinted polymer toward template was studied.Molecularly imprinted polymers was used as the chromatographic stationary phase to test the selective retention toward template molecules,and the solid phase extraction performance of molecularly imprinted polymers was also discussed.?1?MIL-101 was first used as the carrier to prepare ED-MIL-101 by chemically modifying amino group.Then,geniposide ws used as template,methacrylic acid as functional monomer and divinylbenzene as crosslinker agent to prepare molecularly imprinted polymer through surface-imprintig technology.The structure of the MIP was characterized by Fourier transform infrared spectroscopy?FTIR?,X-ray diffraction?XRD?and scanning electron microscopy?SEM?.The adsorption dynamics and therodynamics behaviors were tested and the ability for the MIP in selection recognition was examined.Then,the retention factors of geniposide imprinted polymers were tested under the optimized chromatographic conditions.The performance for this polymer in solid phase extraction was evaluated.The adsorption kinetics study showed that when the MIP is used for geniposide,the adsorption equilibrium can reach within 270 minutes.When the temperature was set at 298,308,318 and 328K,the adsorption capacity for the MIPs toward the template was 55.94,46.16,38.98 and 31.47 mg/g,respectively.Adsorption theromatics analysis indicated an enthalpy value of?H=-26.997 kJ/mol.The relative selection factor was 1.9 for MIP toward geniposide.It indicated that the molecularly imprinted polymer has higher selectivity to geniposide.MIP can be used as the sorbent for solid phase extraction of geniposide from crude extract of Eucommia ulmoides,with a total recovery of 95.0%.?2?A quercetin molecularly imprinted polymer was prepared by using surface imprinting technique with quercetin as template molecule.The effect of functional monomer type and dosage on the adsorption performance of imprinted polymer was investigated.The structure characterization of the polymer was performed by using Fourier transform infrared spectroscopy?FTIR?,X-ray diffraction?XRD?and scanning electron microscopy?SEM?.The adsorption kinetics and isotherm adsorption behavior of the molecularly imprinted polymer were tested.The elution efficiency of different eluents toward quercetin adsorbed on the MIP was investigated and solid phase extraction performance of the molecularly imprinted polymer discussed.Results showed that MIP2 had the highest adsorption capacity toward the target molecule.The adsorption equilibrium could be achieved in 180 minutes,with a faster adsorption kinetics.Saturated adsorption capacity of the molecularly imprinted polymer toward the template molecule was 46.27 mg/g.Isotherm adsorption model of Langmuir,Freundlich and Dubinin-Radushkevich was used to fit adsorption isotherm values and results showed that the adsorption process of quercetin on molecularly imprinted polymer is more suitable for desciption by using Freundlich isotherm adsorption model.Eluting quercetin with water as eluent can acheive the best effect.Molecularly imprinted solid phase extraction can be applied to separate and enrich quercetin from crude extract of Eucommia ulmoides,with a total recovery of 98.26%.?3?A caffeic acid imprinted polymer based on ED-MIL-101 as the matrix was prepared by using surface imprinting technique with caffeic acid as the template.The influence of the type and volume of functional monomer on the adsorption capacity of the MIPs was explored.The MIPs obtained were characterized by using Fourier transform infrared spectroscopy?FTIR?,X-ray diffraction?XRD?and scanning electron microscopy?SEM?.The retention behavior of caffeic acid and its structural analogues on molecularly imprinted polymers as a chromatographic stationary phase was investigated.The results showed that MIP4 obtained using 0.2 mmol 4-VP as the functional monomer had the highest adsorption capacity.When the MIPs was used as the adsorbent,the adsorption equilibrium can be reached within 4 h.The second-grade dynamics dsorption model was shown best for describing this adsorption process of the MIPs.Adsorption isotherm was constructed and the saturated adsorption capacity for the MIPs toward the template was 37.62mg/g.Scatchard analysis revealed that there exsisted two types of adsorption sites in the MIPs,with a dissociation constant of2.842×10-2mg/mL and a maximum binding site number of 62.38mg/g for the high affinity sites,and a dissociation constant of 1.972×10-33 mg/mL and a maximum binding site number of 31.04 mg/g for the low affinity sites.Under the optimized chromatographic conditions,the retention factor of the imprinted polymer to the template molecule can reach 10.36,showing higher retention performance.When the molecularly imprinted polymer was used as the adsorbent in solid phase extraction,the recovery of the target was 90.13%?... |
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