Study On The Preparation And Applicaton Of Chloramphenicol Based Molecularly Imprinted Polymer In Food Analysis

As a new technology, molecular imprinting technology is developed rapidly in recent years. Molecular imprinted polymer (MIP) has shown advantages, such as high selectivity and chemical stability and has become a potentinal stationary phase extraction material in the solid-phase extraction. The combination of MIP and solid-phase extraction (namely molecularly imprintde solid-phase estraction, MISPE) has a good prospect in determining trace analytes in drug, food and biological samples.Chloramphenicol as a broad-spectrum antibiotics,is widely used in various infectious diseases and animal feed additives. Because of the improper use and incomplete metabolism, chloramphenicol residues remain in animal-derived food. However, the hazard effect of chloramphenicol residues results a threat to human health. Chloramphenicol residues is an important part in food analysis.Because the content of chloramphenicol in food is low and the matrix of food sample are always complex, it is significance to improve the selectivity and sensitivity of the analytical method. Solid-phase extraction is a common method of improving selectivity and sensitivity, and the key is the performance of solid-phase extraction material.In this research, a chloramphenicol molecular imprinted polymer (CAPMIP) was prepared, and the preparation conditions of CAPMIP and the operation parameters of MISPE were optimized. The major conclusions are as follows:1. Molecular imprinted polymer (MIP) was prepared with chloramphenicol as the template molecule and methacrylate as monomer. The prepared CAPMIP has excellent performance, through the optimization of the proportion of monomer, crosslinker and polymerization temperature factors. It was shown that the property of CAPMIP were satisfactory when the ratio of template molecule, monomer and crosslinker was 1:4:24, polymerization temperature was 60℃.2. CAPMIP was used solid-phase extraction matercial, and the extraction condition were optimized as: 5 mL methanol, 5 mL acetonitrile and 5 mL water were used to activate the MIP column respectively, loading with 2 mL 10% the ethanol solution, washing with 3mL 20% acetonitrile solution and eluting with 2 mL acetonitrile. Under these conditions different concentrations (1~15μmoL/L) of chloramphenicol could be recovered. The recoveries were between 74.3 to 96.7%. MISPE can selectively and quantitatively recover the chloramphenicol of the samples.3. The combination of subcritical water extraction and MISPE were used in determination of chloramphenicol in feed. The standard addition recoveries of 0.02, 0.05, 0.1μmoL/g were 76.6%, 80.6% and 84.8% respectively. In contrast to subcritical water extraction alone, the combination of subcritical water extraction and MISPE showed better separation performance.