| Molecular imprinting technology has the advantages of specific selectivity and specific identification,which the compounds with similar structure can be effectively separated, so it has been widely applied tofood safety, environmental protection and biological technology, and application prospect is broad. Inrecent years, solid phase microextraction(SPME) and stir bar sorptive extraction(SBSE) as samplepretreatment technology has been applied in environmental samples, biological samples and food testingand other fields. This paper mainly prepared a series of magnetic stir bar and a kind os steel fiber and usedthem to pretreat some food samples, coupled with high performance liquid chromatography(HPLC).1. A novel monolithic stir bar based on molecularly imprinted plolymer (MIP) was firstly developed byfilling modified neodymium magnet (Nd2Fe14B) powders into a glass tube (604mm), followed by theimprinted grafting with bisphenol A (BPA) as the template molecule by thermal polymerization. Theexperimental conditions of MIP-SBSE, such as, extraction time, desorption time, pH and salt concentrationwere optimized. Under the optimal extraction conditions, a simple method based on the coupling ofMIP-SBSE with HPLC was used for the selective determination of the model mixtures of BPA,4-phenylphenol (PP) and phenol (P) in bottled water. The recoveries of BPA, PP and P were in the range of88.5-96.1%,78.2-89.7%,81.3-89.5%at three spiked levels, respectively.2. The new matrix of Nd2Fe14B powders with high magnetic and super paramagnetic property wasused as a muddler magnetic supply in order to prepare sorptive extraction stir bars based on the molecularimprinting technique. It was carried out by a stepwise polymerization using malachite green (MG) astemplate, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) ascross linking agent. The experimental conditions such as extraction and desorption time, pH value andconcentration of salt were optimized in SBSE process. It was successfully applied to the pretreatment andanalysis of MG by HPLC in real samples. The experimental results indicated that under the optimizedexperimental conditions, the method showed good linearity in the range of10-500μg/L with a detectionlimit of0.10μg/L for MG and a spiked recovery in the range of87.5%-94.0%.3. An in-situ polymerization method was used in the preparation of a novel SPME coating，wherebutyl methacrylate-ethylene glycol dimethacrylate (BMA-EDMA) was directly bonded to the surface of amodified stainless steel wire．Coupled to HPLC，the prepared coating was applied to the extraction and determination of sudan Ⅰ—Ⅲ dyes in fermented bean curd．The experimental conditions of SPME，suchas extraction time，desorption time and salt concentration were optimized．As a result，the run-to-run (n=3)and fiber-to-fiber (n=6) relative standard deviations of this method were lower than9.19%and16.48%,respectively; and the recoveries of Sudan Ⅰ—Ⅲ dyes were in the range of79.54%~86.37%; the linearrelationships between the concentration50μg/L and900μg/L for Sudan Ⅰ—Ⅲ dyes were obtained (r2＞0.9232); the limits of detection ranged from0.303μg/L to1.808μg/L in the optimal conditions.4. An in-situ polymerization method was used in the preparation of a novel SBSE，where α-methylacrylic acid-ethylene glycol dimethacrylate (MAA-EDMA) was directly bonded to the surface of modifiedMagnetic powder．The experimental conditions of SBSE, such as extraction sorvent, extraction time,desorption time and salt concentration were optimized. Coupled to HPLC, the prepared stir bar sorptiveextraction was applied to the extraction and determination of plasticizers in water sample.. As a result, therecoveries of DBP, DMP and DEP were89.2%~92.1%,91.9%~96.6%and94.3%~96.7%, respectively; thelinear relationships between the concentration5μg/L and800μg/L for DBP were obtained; the limits ofdetection ranged from0.09μg/L to0.21μg/L in the optimal conditions. |
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