Preparation And Application Of Novel Molecularly Imprinted Polymers Based On MOF Materials

Molecularly imprinted polymers（MIPs）are a kind of novel polymer materials that has been developed rapidly in the past two decades.It attracts intensive attentions due to its advantages such as good specificity and wide practicability.In order to solve the problems of traditional MIPs including slow mass transfer rate and low identification efficiency,an effective method is to use porous materials as carrier to synthetic MIPs.In this thesis,three novel metal organic frameworks（MOFs）-molecularly imprinted polymers（MOFs@MIPs）were synthesized using porous MOF materials（NH₂-MIL-101（Cr）and SOM-ZIF-8）as carriers.As pretreat adsorption agents,MOFs@MIPs were used respectively for the enrichment of diclofenac sodium（DS）,ochratoxins A（OTA）and zearalenone（ZEN）in actual samples,and then the analytes were detected by high performance liquid chromatography（HPLC）.The main contents are as follows:（1）Detection of DS based on a novel solid phase extraction adsorbent MIL-101（Cr）@MIPsA novel molecularly imprinted polymer（MIL-101（Cr）-MIP）was prepared using porous MOF（MIL-101（Cr））as the carrier.The as-synthesized MIL-101（Cr）-MIP is of good dispersion,large surface area and great adsorption capacity(optimal adsorption time:30 min,adsorption capacity:15.8 mg·g^-1),as well as excellent selectivity and repeatability for DS adsorption.MIL-101（Cr）-MIP was used as the pretreat adsorbent of dispersive solid phase extraction（DSPE）for the enrichment of DS in urine,and the adsorbed DS was detected by HPLC.Under optimal conditions,the range of average recovery of DS was 88.3～101.6%,with relative standard deviation（RSD）of 5.6%.This research provided a high selective and accurate pretreat method for the detection of DS in human urine.（2）Detection of OTA based on SOM-ZIF-8@MIPs as a novel solid phase micro-extraction（SPME）coatingThe SOM-ZIF-8/MIPs were fabricated by combinating structural analogs of OTA as the template molecules,alobarbital as the functional monomer and porous MOF（SOM-ZIF-8）as the carrier.The synthesized SOM-ZIF-8/MIPs were adsorbed on the surface of glass capillary by sol-gel method to prepare SOM-ZIF-8/MIPs-SPME for the adsorption of OTA.The results demonstrated that SOM-ZIF-8/MIPs had great adsorption capacity to OTA(adsorption time:30 min,adsorption capacity:1.3 mg·g^-1)with good selectivity and repeatability.The SOM-ZIF-8/MIPs-SPME was used as the adsorbent coating for the enrichment of OTA in rice and corn samples,and the adsorbed OTA was detected by HPLC.Under optimal conditions,the range of average recovery of OTA was82.0～103.1%,with RSD less than 2.7%.The research provides a simple and high selective pretreat method for the detection of OTA in moldy food.（3）Detection of ZEN based on a novel extraction membrane SOM-ZIF-8@MIPsThe MOF/MIPs were fabricated by combinating structural analogs of ZEN as the template molecules,alobarbital as the functional monomer and porous MOF（SOM-ZIF-8）as the carrier.The synthesized MOF/MIPs were combinated with polyvinylidene fluoride（PVDF）to fabricate a novel extraction membrane MOF/MIPs-M for the adsorption of ZEN.The results demonstrated that MOF/MIPs-M had great adsorption capacity to ZEN(adsorption time:45 min,adsorption capacity:241.7μg·g^-1)with good selectivity and repeatability.The liner range of detection was 12～30 ng·g^-1（R²=0.9957）,with a limit of detection（LOD）of 1.7 ng·g^-1 and a limit of quantification（LOQ）of 5.1 ng·g^-1.The MOF/MIPs was used as the adsorbent membrane for the enrichment of ZEN in grain samples,and the adsorbed ZEN was detected by HPLC.Under optimal conditions,the range of average recovery of ZEN was 83.8～97.0%,with RSD less than 8.9%.The research provides an efficiently,selective and accurate pretreat method for the detection of ZEN in grain.