Application Of Magnetic Covalent Organic Framework Materials In Sample Pretreatment

Food analysis and drug analysis have always been a hot topic,established an excellent sample pretreatment method can eliminated the interference of complex matrix,shorten the analysis time,improve the selectivity and sensitivity.At present,magnetic solid phase extraction technology has been favored by researchers.This technology does not need the process of column filling,avoids the steps of centrifugation and filtration,greatly shortens the analysis time,and has high selectivity and sensitivity.In this study,synthesized magnetic covalent organic framework materials as magnetic solid phase extraction adsorbents,and combined with high performance liquid chromatography or fluorescence spectrophotometer,established three analytical methods of polycyclic aromatic hydrocarbons,fluoroquinolones andβ-blockers in food and medicine.1.Introduced several kinds of sample pretreatment technologies which have developed rapidly in recent years.And introduced the process and advantages of magnetic solid-phase extraction,the kinds of adsorbents and the application of magnetic solid-phase extraction in sample analysis.2.Synthesized the magnetic covalent organic framework（Fe₃O₄@COF（TP-NDA）） by solvothermal method which as a magnetic solid phase extraction adsorbent to separate and enrich trace polycyclic aromatic hydrocarbons in tea,coffee,lake water and fried chicken,and detected by HPLC-UV detector.Under the optimized conditions,the adsorption equilibrium can be achieved in 3 min.The prepared magnetic adsorbent can be reused for 10 times,the detection limit is 0.05-0.25μg·L^-1,and the quantitative limit is 0.17-0.83μg·L^-1.The recovery of the analyte in the actual sample is 74.6-101.8%.The relative standard deviation of intraday and intraday were less than 4.2%.3.Used Fe₃O₄@COF（TpPa-1）as magnetic solid phase extraction adsorbent,combined with HPLC-UV detection technology,established an analytical method for the determination of fluoroquinolones residues in milk samples.The linear range of the established method is 0.5-2000μg·L^-1,the detection limit is 0.05-0.20μg·L^-1,and the recovery of fluoroquinolones is 94.3-101.5%.The relative standard deviation of intraday and intraday was less than 5.4%.4.Established a method which using the magnetic covalent organic framework Fe₃O₄@COF（TpBD）as the magnetic solid phase extraction agent combined with synchronous fluorescence detection for simultaneous determination of propranolol and carvedilol in plasma and urine.Studied the effects ofΔλand interfering ions,and optimized the experimental parameters affecting the recovery.At the same time,under the optimal conditions,verified the method by the spiked experiment.In the standard addition samples,the recoveries of propranolol and carvedilol were 94.8-101.4%,and the relative standard deviation was less than 3.7%.