Facile synthesis of a core-shell structured magnetic covalent organic framework for enrichment of organophosphorus pesticides in fruits.
A facile strategy was developed for the fabrication of a magnetic covalent organic framework (COF) via grafting of the monomers, 2,5-dihydroxyterephthalaldehyde (Dt) and 1,3,5-tris(4-aminophenyl) benzene (Tb) onto surface-modified Fe3O4 nanoparticles. The magnetic COF, named as magnetic COF-DtTb, was readily fabricated without high temperature or harsh reaction conditions. The synthesized magnetic COF-DtTb nanoparticles were fully characterized, presenting a regular core-shell spherical structure, large specific surface area, superparamagnetism, and good thermal stability. Their potential as an enrichment adsorbent was investigated to establish an efficient magnetic solid-phase extraction method for the determination of organophosphorus pesticide residues in fruits. Systematic method validation revealed good linearity in the concentration range of 1-200 μg L-1 (correlation coefficient >0.9957). The method limits of detection were in the range of 0.002-0.063 μg kg-1, the method limit of quantification was 1.00 μg kg-1 and recoveries ranged from 72.8% to 111% with RSDs lower than 12.3%. The results indicated that magnetic COF-DtTb possesses superior trace enrichment properties for organophosphorus pesticides in fruits.
['Lin|Xiangping|X|', 'Wang|Xinquan|X|', 'Wang|Jiao|J|', 'Yuan|Yuwei|Y|', 'Di|Shanshan|S|', 'Wang|Zhiwei|Z|', 'Xu|Hao|H|', 'Zhao|Huiyu|H|', 'Qi|Peipei|P|', 'Ding|Wei|W|']
D000327:Adsorption D002853:Chromatography, Liquid D003372:Coumaphos D005638:Fruit D057230:Limit of Detection D058185:Magnetite Nanoparticles D000073396:Metal-Organic Frameworks D009946:Organothiophosphorus Compounds D010573:Pesticide Residues D010706:Phosmet D052616:Solid Phase Extraction D021241:Spectrometry, Mass, Electrospray Ionization D053719:Tandem Mass Spectrometry
Magnetic covalent organic framework Organophosphorus pesticides Fruits Magnetic solid-phase extraction