Application Of Magnetic Adsorbent Coated With Metal-Organic Framework Material In The Detection Of Organic Pollutants In Food And Environmental Water

Organic pollutants,as the main environmental pollutants nowadays,are produced in the usual agriculture and industrial production,and then discharged into environmental water or remain in agricultural products,and eventually ingested by humans in their daily activities.At present,the use of magnetic solid phase extraction?Magnetic solid phase extraction,MSPE?method to extract organic pollutants and then use high-performance liquid chromatography for analysis is a common method for detecting organic pollutants,but because organic pollutants are dispersed in more complex Within the matrix,it is imminent to develop a magnetic solid phase extraction adsorbent with excellent extraction capacity.In this paper,according to controlling the reaction temperature and initiator modified to the surface of Fe₃O₄,what make the organic ligand and metal ions on the surface of Fe₃O₄ self-assembly synthesis of Fe₃O₄@MIL-100?Fe?Magnetic nanoparticles.With the help of high performance liquid chromatography-diode array detector?HPLC-DAD?,phenylurea herbicides and Sudan dyes were extracted and enriched from environmental water,rice and chili paste for detection.Through theoretical calculations and the construction of molecular models,the mechanism of interaction between Fe₃O₄@MIL-100?Fe?MNPs and organic pollution?Van der Waals force,electron donor-acceptor interaction and hydrogen bonding?was inferred.At the same time,the experimental data and theoretical calculations verify that the prepared Fe₃O₄@MIL-100?Fe?MNPs has high porosity,stable conjugated structure and strong hydrogen bonds,and has a high adsorption capacity for organic pollutants.First,it was proved by experiments that Fe₃O₄@MIL-100?Fe?MNPs can effectively adsorb and extract phenylurea herbicides in environmental water samples and rice samples.In environmental water samples,the detection limit?S/N=3?of phenylurea herbicides is0.037-0.166 ng/mL,the correlation coefficient is 0.9990?R²?0.9995,the intra-day precision is 1.31%-3.22%,during the day The precision is 1.53%-3.85%.The detection limit of phenylurea herbicides in rice samples was 0.127-0.254 ng/g,the correlation coefficient was 0.9986?R²?0.9992,the intra-day precision was 1.71%-2.73%,and the intra-day precision was 1.93%-4.14%.Then,Fe₃O₄@MIL-100?Fe?MNPs were applied in chili sauce to extract Sudan dyes I-IV.In the range of 5-5000 ng/g,it showed a good linear correlation?0.9984?R²?0.9997?and a very low detection limit?0.215-0.450 ng/g?.The intra-day precision is between 0.87and 4.69%,and the intra-day precision is between 1.51 and 4.86%.Moreover,the extraction time is 7.5 min,which is superior to most previously published literatures for the detection of Sudan dyes I-IV.In summary,the experimental results show that Fe₃O₄@MIL-100?Fe?MNPs is a stable and highly efficient MSPE adsorbent with specific adsorption for organic pollutants.