Synthesis And Application Of Solid Phase Extraction (SPE) Materials For The Content Analysis Of Complex Matrix Drugs (Poisons)

The content analysis of drugs?poisons?in complex matrix is closely related to our lives.Therefore,the selection of cheap and efficient solid phase extraction?SPE?materials has been a hot topic in the field of chemical analysis.In recent years,with the joint efforts of analysts all over the world,some new type of SPE materials have been developed,such as molecularly imprinted polymers,nanomaterials and biological adsorbents.Compared with traditional SPE materials,these new SPE materials often have the advantages of high enrichment efficiency,less amount of organic solvent,easy automation and diversified operation modes in the pretreatment analysis,so they are widely accepted for sample analysis in many fields such as food and medicine.Based on this,some new types of SPE materials were developed in this study.The molecularly imprinted polymers about 4-methylimidazole and clenbuterol were synthesized for the first time respectively,and were detected by HPLC.In addition,solid phase microextraction?SPME?fibers that can recognize lamotrigine specially were synthesized.These studies have confirmed that the specific and accurate detection of drugs?poisons?in complex matrix was achieved.The details are as follows:?1?On the basis of magnetic molecularly imprinted polymer?MMIP?solid-phase extraction coupled with high performance liquid chromatography,we established a new method for the determination of the 4-methylimidazole?4-MEI?in soy sauce.Scanning electron microscopy,Fourier transform infrared,X-ray diffraction and vibrating sample magnetometer were used to characterize the synthesized MMIPs.To evaluate the polymers,batch rebinding experiments were carried out.The binding strength and capacity were determined from the derived Freundlich isotherm?FI?equation.The selective recognition capability of MMIPs was investigated with a reference compound and a structurally similar compound.As a selective pre-concentration sorbents for 4-methylimidazole in soy sauce,the MMIPs showed a satisfied recoveries rate of spiked samples,ranged from 97%to 105%.As a result,the prepared MMIPs could be applied to selectively pre-concentrate and determine 4-methylimidazole in soy sauce samples.?2?Magnetic molecularly imprinted polymer?MMIP?was successfully synthesized with acrylamide as functional monomer and clenbuterol?CLB?as template molecule.The synthesized MMIPs was characterized by scanning electron microscope?SEM?,X-ray diffraction?XRD?and Fourier transform infrared spectrometer?FT-IR?.MMIPs was used to identify and bind CLB as a solid phase extraction material.The experiment data was fitted by the Freundlich isotherm adsorption model.The results show that MMIPs have excellent recognition performance for CLB.MMIPs was successfully applied as adsorbents to pre-concentrated CLB in pork samples and detect by HPLC with UV.The limit of detection?LOD?and limit of quantification?LOQ?were4.27?g L^-11 and 14.2?g L^-1,respectively.The spiked recovery rates ranged from 94.44%to102.29%.Therefore,the prepared MMIPs can be used for selective pre-concentration of CLB content in complex animal-derived food samples.?3?Solid-phase microextraction?SPME?fibers with different coatings were prepared by chemical deposition method based on stainless steel wire.Etching the stainless steel wire with hydrofluoric acid,making it rough and porous.This greatly increases the specific surface area of the stainless steel wire and enables the rapid preparation of porous gold-coated SPME fibers with large specific surface area,strong bond and controllable thickness.In addition,dopamine is a kind of biochemically active substance,which can be used to modify the nano-solid-metal micro-extraction fiber to make it more selective,and the dopamine-nano-gold composite coating SPME fiber can be prepared.