Based On Reusable Molecularly Template Synthesis Of Indole Butyric Acid Imprinted Polymers And Analytical Application

Fluorescence analysis provides an important tool for the analysis anddetermination of trace analytes in complex samples, due to its many features such ashigh sensitivity, selectivity, using less amount of sample, the simple instrumentation,rapid determination and so on. Molecularly imprinted polymer (MIP) is a type ofsynthesized material with specific recognition ability to the imprinted template.Therefore, MIPs could be utilized for SPE in compound-specific and group-specificextraction modes. Combining fluorescence method with molecularly imprintedsolid-phase microextraction can improve extraction efficiencies and sensitivity. In thisresearch, An improved multiple co-polymerization technique combined withfluorescence were developed to prepare a novel molecularly imprinted polymer(MIP)-coated solid-phase microextraction (SPME) membrance using IBA as template.Three type auxins were successfully conjugated with3-aminopropyltrioxysilane(APTES) and immobilized on quartz slide to fabricate a fluorscent sensingmembrance. Here we report the solid-phase synthesis of molecularly imprintedpolymer nanoparticles using reusable template molecular.Main content of the work is as follows:1. We determined fluorescence excitation and emission spectra of IAA, IPAand IBA. The effect of the pH was investigated and pH=9was selected as theappropriate pH for fluorescence measurement; the linear range of calibration curve ofIAA, IPA and IBA were2-24μg/mL，2-16μg/mL，0.5-32μg/mL respectively; thelimit of detection (LOD) of IAA, IPA and IBA were0.565，0.426，0.515μg/mL. andThe limit of quantation (LOQ) of IAA, IPA and IBA were1.62，1.29，1.56μg/mL. Inorder to investigate validity of proposed method, a recovery experiment was carriedout by adding the known amount of standard auxins (IAA, IPA and IBA) mixture intolaboratory tap water and the recovery was found in the range of93.06%～108.69%,RSD was0.26%～2.72%. Comparison of two different extraction methods for mungbean was performed. By liquid-liquid extraction,0.68μg/g of auxin content wasfound with recovery in the range of99.5%～101.25%, with RSD less than3.6%. Andby MISPE method, effective extraction was achieved and auxin content was found tobe0.96μg/g with recovery in the range of90%～100%, and its RSD was less than 4.5%。2. The purpose of this part was to prepare a novel IBA-MIP-SPME coating byimproved multiple co-polymerization method with IBA as template, under theoptimized condition in which MAA, EGDMA, chloroform were used as functionalmonomer, across-linker, polymerization solvent respectively. A series IBA standardsolution of10～60mg/L in buffer pH=2.5were used to investigate the extractionperformance. When equilibrium reached, the extraction capacities of IBA-MIP-SPME coating was about16.89mg/L; The selectivity of the MIP-and NIP-coatedwas investigated with IAA, IPA and TA as the structural analogues of IBA template.The result indicated that IBA-MIP-SPME has high selectivity to template IBA.IBA-MIP-SPME coating can clean up auxins from mung bean extraction andrecovery was in the range of72.4～83.3%with RSD (n=3) less than7.4%。3. IPA and IBA was successfully condensed with3-aminopropyltrioxysilane(APTES) by using IAA. The chemical structures of the synthesized substances wascharacterized by the1H-NMRm, IR Spectral, UV and Fluorescence.4. Molecularly imprinted nanoparticles were prepared by applying theimmobilized template solid-phase synthesis approach with MAA as functionalmonomer, EGDMA and TRIM as across-linker, acetonitrile as polymerization solvent,N,N-diethldithiocarbamic acid benzly ester as iniferter and pentaerythriol-tetrakis-(3-mercaptopropionate) as chain transfer agent under UV irradiation. IBA-MIN wasalso used to extract auxins from mung bean and the extraction recovery was in therange of88.75%～91%with RSD (n=3) less than3.6%。...