Preparation Of Novel Molecularly Imprinted Polymer Composite And Detection Performance For Sulfonamides Drug Residues

Sulfonamides?SAs?as antibiotic drugs are the emerging contaminants closely linked to people's daily life.The harmful residues of SAs drug originating from food products of animal increase the risk of people's health.However,many problems such as complicated existence form,low content and various interference lead to numerous errors in the test procedure.Therefore,the studies of pretreatment and detection technology for SAs drug residues in food sample are significant in academic and application.The main work of the article is as follows:Molecularly imprinted polymer/graphene oxide?MIP/GO?as a novel solid phase extraction adsorbent was prepared by precipitation polymerization.The adsorption quantity of MIP/GO was 1.5 times than that of the traditional MIP and it showed high selectivity for the template sulfadimidine?SM2?.The recovery range was90.55%-103.20%and the standard deviation was 3.36%-5.33%by HPLC for the analysis of SM2 in milk.This pre-treatment method was simpler,cleaner extractions and possessed high enrichment efficiency.Hollow silica?SiO₂?spheres as new stationary phase for HPLC were prepared by hard template and sol-gel technology.Polystrene?PS?latex was used as template and was removed from PS@SiO₂ by high temperature sintering.The results indicated that the hollow spheres were uniform with particle diameter of 2?m and the surface area was 511 m²/g.The chromatographic properties were evaluated and the packed column showed low column pressure,high values of efficiency?up to about 43,000N/m?and appropriate resolutions.A theoretical method was established to predict the retention time and peak shapes of sulfonamides under gradient elution in reversed-phase HPLC based on the plate theory.This approach was carried out by the retention prediction of 13 common sulfonamides in 18 kinds of gradient conditions and at different flow rates.The mean absolute deviation was 1.59%and the mean relative deviation was-0.27%which indicates the accurate prediction effect.At last,the method could also realize the optimization of separation for 13 sulfonamides.These results demonstrated that the proposed method for the retention prediction was efficient and reliable.A novel sensitive electrochemical sensor based on a glassy carbon electrode?GCE?modified with reduced graphene oxide/molecularly imprinted polymer?rGO/MIP?was developed.The rGO/MIP was prepared by the surface molecularly imprinted technique in the presence of SM2 as template molecule.The printing sites were located on the surface of the imprinted material,which could promote the response speed,adsorption and selectivity to SM2 in food sample.Under optimized conditions,the sensor had a wide linear range over SM2 from 0.5 to 500 ng/mL with a detection limit of 0.287 ng/mL?S/N=3?.The recovery range was 91.85%-104.42%and the standard deviation was 2.51%-4.45%.The sensor displays good stability,reproducibility,and does not require pre-processing of the sample,which can be further applied to quantify SAs drug residues in food with fast detection and high sensitivity.A novel 3D MIP sensor was prepared by electropolymerization of pyrrole as the functional monomer onto NiCo₂O₄ nanoneedle arrays on the 3D graphene in the presence of SM2 as template molecule.The 3D MIP sensor has abundant imprinted sites,need not pretreatment of sample and exhibits high sensitivity and good selectivity for SM2 with three dimensional structure.Under optimized conditions,the sensor had a wide linear range over SM2 from 0.2 to 1000 ng/mL with a detection limit of 0.169 ng/mL?S/N=3?.The recovery range was92.3%-102.23%and the standard deviation was 2.27%-4.10%.The 3D MIP sensor can further enhance the selectivity and sensitivity of SM2 and expand its detecting application for SAs drug residues in food.