Preparation Of Magnetic Material And Its Application In Degradation And Detection Of Imidacloprid

The pesticide residues have become one of the issues in the fields of environmental health and food safety.Magnetic nanoparticles on the catalyst surface load,recycling still has high catalytic activity for many times,in the field of water environmental governance has great development potential.Pesticide residue detection is an important means to ensure food safety.The novel magnetic molecularly imprinted polymer（MMIP）material,as a high-performance solid phase extraction adsorbent,can efficiently enrich pesticides and has great potential for pesticide detection in complex food substrates.Fe₃O₄-GO-MnO₂magnetic catalyst was prepared to explore its application as a magnetic catalyst in the catalytic oxidation of organic imidacloprid pesticides.The Fe₃O₄-GO-MnO₂magnetic catalyst has a good effect on the catalytic oxidation of imidacloprid.The catalytic oxidation degradation rate of imidacloprid in water is good,and the average removal rate of imidacloprid can reach more than 90%when the time is less than 30 minutes.The addition amount of catalyst was low,and the reusability was good.The experimental data proved that the catalytic degradation of imidacloprid pesticides in natural water was also reliable.Magnetic molecularly imprinted polymer（MMIP）can be used as a magnetic dispersive solid phase extraction adsorbent to simplify the separation of imidacloprid from water samples.The prepared adsorbent MMIP has good adsorption performance and selectivity to imidacloprid.MMIPs were creatively synthesized in one pot via the nucleation process of Fe₃O₄magnetic nanoparticles and the polymerization process of molecular imprinted polymers（MIP）simultaneously,using imidacloprid as template and dopamine as functional monomer.The MMIPs were characterized by Fourier transform infrared spectrometry（FT-IR）and scanning electron microscopy（SEM）.Adsorption isotherm and adsorption kinetics results suggested that the equilibrium absorption capacity of 1.581 mg/g and the reasonable adsorption time of 30 minutes to MMIPs,respectively.The parameters effected on the extraction efficiency,including p H value and the amount of the adsorbent,were investigated.Under the optimal conditions,the methodological assessment indicated the valid applicability of MMIPs to extract imidacloprid in water samples with excellent recovery（88%-97.3%）and precision（1.2%-3.3%）in determining imidacloprid content.Herein,an effective method was successfully developed to rapidly determine imidacloprid in environmental water samples based on magnetic molecular imprinted polymers（MMIP）coupled with high-performance liquid chromatography（HPLC）.Imidacloprid adsorbed by magnetic molecularly imprinted polymer（MMIP）material was eluted by methanol,which can be used for HPLC-UV analysis.The established standard curve was created,and the correlation coefficient R²of the fitting curve was 0.9988.The method has the advantages of simple analysis,good enhancement coefficient and short analysis time.The results show that this method is a good choice for the determination of imidacloprid trace in aqueous environment.Figure 22 table 6 reference 68...