Study On The Application Of Magnetic Solid Phase Extraction Coupled With High Performance Liquid Chromatograph In The Detection Of Food Contaminants

In recent years,with the rapid development of economy and society,and the improvement of industrialization,the food safety problem occurred frequently,which has a serious impact on human health.In order to ensure food safety,it is an urgent task to vigorously supervise the food quality.Due to the complex composition of the food sample matrix,the extremely low content of the target analytes,and the interference of other components,the performance of detection were often affected by the matrix efffects.So it is necessary to pretreat the sample in a suitable way to achieve the enrichment of the target analytes before sample detection.For the sample pretreatment technology,magnetic solid phase extraction?MSPE?is a novel sample pretreatment technology.The extraction process of MSPE is simple and efficient,which can extract and concentrate the analytes in a short time.The low dosage of organic solvents in the extraction process can reduce the harm of reagent to the environment.In addition,the rapid separation of the target analytes from the mixture could be achieved by magnetic separation,which effectively avoids interference of impurities in the sample.Due to these advantages,MSPE attracts widespread attention and is widely used in the analysis of food samples.In this paper,we synthesized the novel magnetic nanocomposites and applied them to MSPE as adsorbents coupled with high performance liquid chromatography?HPLC?for the determination of polycyclic aromatic hydrocarbons?PAHs?in sausage and barbecue,estrogens in meats,and phenylurea herbicides in the fruits.The specific researched contents were as follows:?1?The novel magnetic nanocomposites?Fe₃O₄@COFs?were prepared and characterized by transmission electron microscopy?TEM?,X-ray diffraction?XRD?,Fourier transform infrared?FT-IR?spectra,N₂ adsorption-desorption isotherms and magnetic properties measurement.Fe₃O₄@COFs were served as adsorbent in MSPE for separation and enrichment of 11 PAHs in sausage and barbecue samples.The PAHs were determined by high performance liquid chromatography with diode array detector?HPLC-DAD?.The influencing factors of extraction efficiency,including elution solvent,amount of adsorbent,extraction time,desorption time and desorption solvent volume were investigated systemically.Under the optimal conditions,the analysis data of 11 PAHs all showed the good linear relationships with their concentration at the concentration ranges of 2-200?g/kg,with correlation coefficients?R²?between 0.9971 and 0.9995.The detection limits?LODs?were in the range of 1.43-56.33 ng/kg.The spiked recoveries of the 11 PAHs in real samples ranged from 83.2%to 119.3%,with the relative standard deviations?RSD?from 1.6%to 5.4%.The proposed method was successfully applied for detection of PAHs in sausage and barbecue samples.?2?The novel magnetic nanocomposites?Fe₃O₄@COFs?were prepared and applied as adsorbent in MSPE for separation and enrichment of 7 estrogens in meats.The estrogens were determined by HPLC-DAD.The influencing factors on extraction efficiency of MSPE,including elution solvent,extraction time,desorption time,amount of adsorbent and desorption solvent volume were investigated systemically.Under the optimal conditions,the analysis data of 7 estrogens all showed the good linear relationships with their concentration at the concentration ranges of 1-200?g/kg,with R² between 0.9974 and 0.9998.The LODs were in the range of 0.7-2.7?g/kg.The spiked recoveries of 7 estrogens in meat samples ranged from 89.8%to 108.4%,with RSD from 1.4%to 6.1%.The proposed method was successfully applied for detection of estrogens in meats.?3?The novel magnetic nanocomposites?Fe₃O₄@COFs?were prepared and as adsorbent in MSPE for separation and enrichment of 3 phenylurea herbicides in fruits.The analytes were determined by HPLC-DAD.Under the optimal conditions,the analysis data of 3phenylurea herbicides all showed the good linear relationships with their concentration at the concentration ranges of 1-200?g/kg,with R² between 0.9960 and 0.9991.The LODs were in the range of 0.8-1.3?g/kg.The spiked recoveries of 3 phenylurea herbicides in fruit samples ranged from 83.5%to 106.5%,with RSD from 1.9%to 4.5%.The proposed method was successfully applied for detection of phenylurea herbicides in food samples.