Research On Preparation Of Scopolamine Molecularly Imprinted Polymer And Application Of Solid-phase Extraction

Scopolamine is a decane type alkaloid which has a higher medicinal value than a tropane alkaloid analog such as atropine,and thus a separation method is required for extracting scopolamine from the mixture of tropane alkaloids.Although the molecular imprinting technique(MIT)can specifically distinct structurally similar substances,the binding sites are almost the same as the conventional functional monomers and the tropane alkaloids are assembled.In view of the inability of molecularly imprinted polymers(MIPs)synthesized by conventional functional monomers to efficiently separate scopolamine from tropane alkaloids,this paper innovatively prepared a novel molecularly imprinted polymer(MIP)with dual recognition sites for enrichment of scopolamine from plant samples.The contents and results of this paper are summarized as follows:1.MFMA-MIP was prepared by precipitation polymerization in supercritical carbon dioxide(scCO2)using scopolamine as template,monoethyl fumarate(MFMA)as jfunctional monomen EGDMA as cross-linker.The structure of the functional monomer and polymers were characterized using H NMR,FTIR,SEM and BET.The advantages of the supercritical fluid technology were verified by comparing the efficiency of the swelling method and the Soxhlet extraction method to remove the template.The assembly mechanism of MFMA and template was studied using NMR.The adsorption performance of MFMA-MIP was evaluated,and the maximum adsorption amount of scopolamine was 49.75 mg/g.As eontrols,AA-co-EAA-MIP were prepared using acrylic acid and ethyl acrylate as a fiunctional monomer.The selection performance of MFMA-MIP was evaluated with a of 3.5,ratio coefficient(P)of hyoscyamine and anisodamine of 1.8 and 2.1,higher than AA-co-EAA-MIP of 1.25 and 1.67,verifying that MFMA-MIP can distinguish the decane alkaloids in the component matrix.2.p-CA-MIP@GO was prepared on the surface of graphene oxide(GO)using scopolamine as template,using p-coduccinic acid(p-CD)as the main functional monomer,using 4-AM as the auxiliary functional monomer,using EGDMA as the cross-linker.p-CA-MIP@GO was characterized by FTIR,SEM and TG to verify the structure,surface morphology and physical properties of MIPs.The isothermal adsorption and adsorption kinetic experiments showed that the GO surface carrier was beneficial to improve the MIP adsorption effect.The maximum adsorption capacity of p-CA-MIP@GO was 77.1 mg/g,which was 5.17 times that of NIP.The selective adsorption factor for scopolamine of p-CA-MIP@GO vas4.7.The p for hyoscyamine and anisodamine is 2.04 and 2.47,which proves that p-CA.MIP@GO can be applied to the separation oftropane alkaloids from biological samples.3.The solid phase extraction column(SPE)and HPLC system were constructed using p-CA-MIP@GO as filling matrix.After optimizing the flow rate,the ratio of the eluent and elution time,the p-CA-MIP@GO-SPE-HPLC system was successfully applied to the analysis of multi-mixed matrix.The recovery of scopolamine was 93.0%-102.0%,much higher than that of hyoscyamine and anisodamine(22.0%-29.0%).In the spiked gold flower and belladonna crude extract,the recovery of scopolamine ranged from 95.0 to 103.0%,and the highest RSD was less than 7.1%.After repeated use of p-CA-MIP@GO-SPE column,the recovery of scopolamine was almost unchanged,which proved that p-CA-MIP@GO-SPE-HPLC system can be successfully applied to the analysis and enrichment of biological samples.