Research On The Application Of Novel Porous Organic Framework Materials For Enrichment And Analysis Of Fungicides And Phenolic Endocrine Disruptors In Water

Metal Organic Frameworks（MOFs）and Covalent Organic Frameworks（COFs）are two types of novel porous organic framework materials.MOFs consist of metal clusters and multifunctional organic ligands,while COFs are formed by covalent bonding of organic ligands containing light elements such as C,B,O,Si,and N.They exhibit excellent properties,such as tunable pore size,high surface area,good thermal and chemical stability,and can be used as efficient adsorbents in sample pre-treatment processes.Excessive use of fungicides can lead to their accumulation in water,soil,and crops,posing a threat to the ecological environment and human health.Endocrine disruptors can negatively affect cell function and cause reproductive and developmental toxicity.These compounds are widely present in environmental water and sediments,and establishing reliable analytical methods to detect fungicides and phenolic endocrine disruptors in water is crucial.Due to the low concentrations of fungicides and phenolic endocrine disruptors in environmental water and the complex sample matrix,appropriate sample pretreatment methods must be used before instrumental analysis to remove sample matrix interference and enrich the target analytes.This article reports the synthesis of two porous organic framework materials,Fe₃O₄@Tp BD and Ui O-66-C,which were utilized for the enrichment and analysis of fungicides and phenolic endocrine disruptors in water.The key findings are summarized as follows:（1）A magnetic covalent organic framework material,Fe₃O₄@Tp BD,was prepared by an in-situ synthesis method and used as an extraction adsorbent to enrich four fungicides（thiabendazole,fuberidazole,carbendazim,and isoprothiolane）in water.Adsorption between Fe₃O₄@Tp BD and fungicides was achieved throughπ-πconjugation,hydrogen bonding,and electrostatic interactions,and a magnetic solid-phase extraction combined with ultra-high-performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）method was developed to determine trace levels of the four fungicides in water.A series of magnetic solid-phase extraction conditions were optimized,including the magnetic proportion and amount of Fe₃O₄@Tp BD,p H of the water sample,adsorption time,type and volume of elution solvent,elution time and salinity,and the optimal extraction conditions were determined.Good linearity was obtained for the four fungicides within the concentration range of 3-1200 ng/L,and the method detection limit and quantification limit were 0.06-0.28 ng/L and 0.20-0.92 ng/L,respectively.The intra-day and inter-day precision ranged from 2.8%to 10.0%and 4.4%to 15.7%,respectively.The method was applied to the detection of the four fungicides in actual water samples,and the spike recoveries in tap water and reservoir water ranged from 77.1%to 119.1%.The method has high sensitivity,good accuracy and precision,and simple and time-saving sample pretreatment,providing a new option for the analysis of fungicides in environmental water.（2）A porous carbon material derived from MOF,Ui O-66-C,was synthesized using a solvothermal method and used as an extraction adsorbent to enrich four types of phenolic endocrine disruptors（bisphenol A,4-tert-octylphenol,4-nonylphenol,and nonylphenol）in water.The adsorption between Ui O-66-C and the phenolic endocrine disruptors was based onπ-πconjugation,pore channel adsorption,and hydrophobic interactions.A vortex-assisted dispersive solid-phase extraction method coupled with UPLC-MS/MS was established to determine the four phenolic endocrine disruptors in water.A series of dispersive solid-phase extraction conditions were optimized,including the amount of Ui O-66-C,p H value of water sample,adsorption time,type and volume of eluent,elution time and salinity.The four phenolic endocrine disruptors showed a linear correlation in the concentration range of 0.5-100μg/L,with detection and quantification limits of 0.01-0.13μg/L and 0.03-0.42μg/L,respectively.The intra-day and inter-day precision were 1.5-10.6%and 6.1-13.2%,respectively.The method was applied to the detection of phenolic endocrine disruptors in tap water and reservoir water,and the recoveries of the four phenolic endocrine disruptors ranged from 77.1%to 116.6%.This method has good accuracy and precision,providing a rapid,efficient,and sensitive new approach for detecting phenolic endocrine disruptors in environmental water.