Molecularly Imprinted-solid Phase Extraction Array Chips For Pretreatment And Its Application In Food Safety Analysis

According to the molecularly imprinted solid-phase extraction?MISPE?technology and carbon nanomaterials technology,three kinds of MISPE monolithic columns integrated with different array microchips were developed.The novel pretreatment device has the advantages of simple,practice,low price and good adsorption/removal capacity,coupling with high performance liquid chromatography?HPLC?for the harmful substances analysis in food samples.The MISPE monolithic columns were prepared by suitable synthetic method and embedded into PDMS/glass chip to form the MISPE array chip for sample pretreatment,which was able to extract the target substances by specific binding sites in polymers and clear-up the matrix in food samples effectively.A method was developed for the sensitive detection of analytes in different food samples by HPLC.This paper includes some parts as following:1.The introduction was started form this: Firstly,the introduction of the research background and significance was presented in this paper.Then,the principle,preparation method and condition,the present development situation and the actual application of molecularly imprinted solid-phase extraction technology were included.The microchip technology,including the preparation methods,materials,the development situation and the solid-phase extraction technology application in microchip,were also described.Moreover,nanomaterials technology was introduced to improve the adsorption/removal capacity of MISPE and encased binding site in MISPE polymers,including the classification,synthesis methods of graphene and the application of molecularly imprinted solid-phase extraction technology coated with nanomaterials.Moreover,the principle,classification and the present research of molecularly imprinted monolithic column were simply introduced.At last,in view ofV the actual food safety problems,the chip-based MISPE polymers coated different functional nanomaterials was proposed as pretreatment technique in this paper.2.Faced with the abuse of food additives,a MISPE-PDMS/glass array chip coated silanized graphene oxide?GO/Si O₂-MISPE?was established as a novel pretreatment device in this part for selective adsorption and sensitive detection of rhodamine B?RB?in chili powder by high performance liquid chromatography-fluorescence detection?HPLC-FLD?.Firstly,the GO/Si O₂-MISPE monolithic columns were synthesized under a suitable condition by using RB as template,methyl acrylamide?MAA?as monomer,GO/Si O₂ as matrix material,ethylene glycol dimethyl methacrylate?EDMA?as crosslinker,methanol: toluene: dodecanol?0.5:1:1.5,v/v/v?as mixed porogen and azodiisobutyronitrile?AIBN?as initiator.Besides,the combination of silanized coverglass and prepared PDMS substance was succeed by plasma bonding means to obtain PDMS/glass hybrid chip.Four GO/Si O₂-MISPE monolithic columns were embedded into the microchannels in chip to carry out the process of activation,sample injection,washing and elution on the array chip drive with the help of micro-injection pump.The GO/Si O₂-MISPE monolithic columns were prepared by optimizing the molar ratio of template/monomer/ crosslinker?T:M:C?,polymerization conditions?including means,time,temperature?,the types and ratios of porogen and eluant.The inner morphology and molecular structure of GO/Si O₂-MISPE columns were characterized by scanning electron microscopy?SEM?and Fourier transform-infrared?FT-IR?spectroscopy.The adsorption capacity and specificity of homemade monolithic columns and property and enrichment factor of array chip were investigated by HPLC.The GO/Si O₂-MISPE array chip as pretreatment method was reliable for RB detection with advantages of simple,accurate,high sensitivity and good effect in actual sample analysis.3.Faced with the safety problems of environmental hormone residues in aquatic products,an analytical technique for selective,simultaneous determination of bisphenol A?BPA?and nonyl phenol?NP?in grass carp samples was established by a dual-imprinted MISPE-PDMS/glass array chip coated silver-modified graphene oxide?Ag/GO?in this part.The dual-imprinted MISPE monolithic columns wereVI synthesized successfully by in-situ polymerization using BPA and NP,MAA,Ag/GO,EDMA,methanol:toluene?1:0.3,v/v?,AIBN as dual-templates,monomer,supporting matrix,crosslinker,mixed porogen and initiator,respectively.In addition,eight good performance columns were selected and embedded into SPE channels of array chip,which bonded to silanized glass to obtain Ag/GO-MISPE chip and connected with injection pump and collection device by two inlet/outlet ports for the next process.The hybrid array chip device showed higher binding capacity and better selectivity to two analytes-BPA&NP.Some influence factors such as T:M:C ratio,polymerization conditions,the types of porogen and eluant were optimized in this experiment.The morphology and structure of Ag/GO-MISPE monolithic columns were characterized by SEM and FT-IR spectroscopy.Adsorption capacity and specificity of Ag/GO-MISPE columns and different properties and enrichment factors of dual-imprinted array chip were also tested.The results showed the proposed method could feasibly applicable to simultaneous determination of BPA and NP in aquatic products samples.4.Faced with the actual status of antibiotic drug residues in animal-derived samples,a novel method for simultaneous determination of tetracycline?TC?,chlorotetracycline?CTC?and deoxytetracycline?DC?in egg samples was established by radiant-type multi-imprinted MISPE-PDMS/glass array chip coated magnetic graphene oxide?Fe₃O₄/GO?.Three kinds of Fe₃O₄/GO-MISPE columns of TC,CTC,DC were prepared by in-situ polymerization with TC,CTC,DC as single templates,using MAA,Fe₃O₄/GO,EDMA,methanol:acetonitrile:butanediol?1:1:0.3,v/v/v?,AIBN as monomer,matrix material,crosslinker,mixed porogen and initiator,respectively.Afterwards,each of the four Fe₃O₄/GO MISPE monolithic columns of TC,CTC,DC were elected and embedded into 12 microchannels of PDMS substrate,which then bonded to silanized glass for the next process.Same as above steps,the influence factors such as T:M:C moral ratio,synthetic conditions,the types of porogen,eluant and washing solvent were optimized by turns in this experiment.The inner morphologies and molecule structures of Fe₃O₄/GO-MISPE columns were examined by SEM and FT-IR spectroscopy.Adsorption capacity and specificity ofFe₃O₄/GO-MISPE columns of TC,CTC,DC and properties and enrichment factors radiant-type multi-imprinted array chip were also investigated by HPLC-FLD.