| Lincomycin (lincomycin, LIN) belongs to the Lincosamides antibiotic drug, which is widely used in the prevention of animal diseases. Due to improper use and incomplete metabolism, drug residues in animal-derived food was caused. Detection of it was an important part of the food safety testing in our country. But because of lower average content of drug residues in food samples, and the complex sample matrix, it was significance to look for a highly specific selective extraction material. With molecularly imprinted polymer (Molecularly imprinted polymers, MIP) used as adsorbent materials, molecularly imprinted solid-phase extraction column (Molecularly imprinted solid phase extraction, MISPE) could enrich the target molecules from the complex sample matrix accurately. So molecularly imprinted solid phase extraction provides a new efficient and effective sample pre-treatment method in determining trace analyses in drug.Based on the above situation, the thesis was mainly composed of the following three parts.1The selection of functional monomerThe interaction binding energies between lincomycin using as template of molecularly imprinted polymers and function monomers were calculated by molecular dynamics through Material Studio. Acrylamide (AM), Methyl acrylic acid (MAA)2-Vinyl pyridine (2-VP) and4-Vinyl pyridine (4-VP) were taking as function monomers. Then the MIP had been prepared by LIN as template and the above monomers as function monomers respectively. According to molecular mechanics calculation, LIN with4-VP had the highest binding energy which was-98.26kj/mol. The adsorption capacity of MIP was testing by gas chromatography(GC). The results showed that the complex of LIN with4-VP had the maximum adsorption capacity which was102.8umol/g meaning the binding capacity of it was stronger than other function monomers, the same to the analysis of molecular mechanics calculation.4-VP was selected as the best function monomer for MIP.2The preparation and performance characterization of lincomycin molecularly imprinted polymer (LIN-MIP)Molecular imprinted polymer was prepared by LIN as the template molecular and 4-VP as monomer. The preparation conditions of MIP had been optimized from the proportion of monomer, the proportion of crosslinker, polymerization temperature and polymerization time. LIN-MIP with the best compositions were obtained. It was0.5mmol LIN,5mmol4-VP,15mmol EGDMA, at60℃for24h.Then the characterization of LIN-MIP was evaluated. The shape, size of the imprinted polymer were observed by Scanning electron micrograph (SEM). Ultraviolet ray (UV) analysis was used to study the interaction between LIN and4-VP. It showed that there was hydrogenbond between MIP and the template. High retention factor and selective adsorption ability were achieved by static adsorption experiment, dynamic equilibrium adsorption experiment and Scatchard analysis. Compared with non-imprinted polymer(NIP) particles, the MIP sorbent showed high adsorption capacity and selectivity for lincomycin. Imprinted factor was2.54and the equilibrium adsorption reached about150min. Scatchard analysis showed that there were2classes of binding sites forming in the MIP.3Lincomycin molecularly imprinted solid phase extraction column (LIN-MISPE) apply to preconcentration of LINWe use the LIN-MISPE-GC to develop a new method for LIN detection. Compared to the methods of C18, it exhibited high precision and robust accuracy for LIN at all three spiked levels of0.15,0.3and0.5μmol/L in milk samples, and the recovery were83.6%,87.9%,89.3%. The analysis of Gas chromatography chromatogram showed that LIN-MISPE had the potential to apply to selective separation and preconcentration of LIN. |
PDF Full Text Request