Establishment Of New Detection Methods For Clenbuterol And Quinolones In Food

Clenbuterol(CLB)belongs to β-agonists,having nutrition repartitioning effect,which is illegal used as a growth promoter in the livestock and poultry production to promote animal growth and increase the muscular mass.The quinolones is a kind of commonly-used antibiotic in livestock and aquaculture.However,CLB and the quinolones residues in food will threaten human health.Thus,it is necessary to establish a high selective and sensitivity analytical technique with efficient sample pretreatment.In this paper,molecular imprinting technique was employed to develop a biomimetic immunoassay for the determination of CLB and a novel upconversion fluorescence probe for determination of quinolones,which offered technical support for improving detection methods of food safety in our country.The derivative was synthesized by chemical reactions between CLB and methacryloyl chloride,which was characterized by nuclear magnetic resonance and mass spectrometry analysis,and the results showed that the CLB derivative was suitable for preparation CLB molecularly imprinted polymers biomimetic antibody.A novel CLB molecularly imprinted polymers(CLB MIPs)was synthesized by covalent imprinting approach using CLB derivative as compound functional monomer,ethylene glycol dimethacrylate as cross-linker,azobisisobutyronitrile as initiator on the well surface of a 96-Well microtiter plate.The conditions of polymerization were studied,and the selectivity and reuse of the MIPs were investigated.Under the optimized experimental conditions,the MIPs biomimetic antibody had good selectivity and adsorption performance.The biomimetic immunoassay was developed for determination of CLB based on this MIPs,and the linear range of the calibration curve was 10-5～103 μg/L,the minimum limit of detection was 10-7μg/L.To assess the analytical efficiency of biomimetic immunoassay,pork and water samples were spiked with CLB.The average recoveries of the spiked samples were 86.02～103.00%and 80.7～110.0%.The developed method was simple,fast and sensitive,meeting the need of CLB trace analysis.A novel quinolone magnetic molecularly imprinted fluorescent probe was synthesized by surface molecular imprinting technique with Fe3O4 nanoparticles and upconversion fluorescent microparticles using enrofloxacin as template,methyl acrylic acid as functional monomer,ethylene glycol dimethacrylate as cross-linker,benzophenone as initiator.The magnetic MIPs fluorescent probe(MIP@MUCPs)was characterized by transmission electron microscope,Fourier transform infrared spectroscopy,X-ray diffraction and vibrating sample magnetometer.The binding experimental results showed that the obtained MIPs probe had high adsorption capacity,good selective and fast adsorption kinetic(reaching adsorption equilibrium within 15 min at 60 μg/L)and stable fluorescence property.Five quinolones can significantly quench the MIP@MUCPs probe,and the standard curves for the five quinolones were under optimized experimental conditions.To assess the analytical efficiency of this fluorescent assay,tarphops oligolepisr samples were spiked with five quinolones,and the average recoveries of the spiked samples were 90.33～108.43%with relative standard deviation(RSD)below 5.53%(n=3).This method is simple,fast and economic,which is suitable for the quinolones trace detection in fish samples.