Facile synthesis of a novel magnetic covalent organic frameworks for extraction and determination of five fungicides in Chinese herbal medicines

Abstract

The research of detection technologies and limited standards of disinfectant residues in food, Grant/Award Number: Z211100007021008A novel magnetic covalent organic framework was synthesized via a one-step coating approach with solvothermal reaction employing 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and 2,4,6-triformylphloroglucinol as two building blocks by covalent bonding. The prepared magnetic covalent organic frameworks were properly characterized by different techniques and employed as adsorbents of magnetic solid-phase extraction. An analytical method was developed for the simultaneous determination of five fungicides in two Chinese herbal medicine samples via magnetic solid-phase extraction coupled to ultra high performance liquid chromatography with tandem mass spectrometry analysis. Under optimized magnetic solid-phase extraction conditions, the method exhibited satisfactory recoveries (74.0−109.6%) with relative standard deviations of 0.4−4.6%, low limits of detection (0.003−0.015 μg/kg), and good linearity (R 2 > 0.9960).Compared with the traditional extraction method, the proposed method required a lower amount of adsorbent (3 mg) and extraction time (5 min). The adsorbent also had favorable reusability (not less than eight times). Therefore, the magnetic covalent organic frameworks could be a promising adsorbent for the extraction and quantitation of fungicides in Chinese herbal medicines.

Magnetic Covalent Organic Framework Composites for Wastewater Remediation

“…To mitigate these issues, surface modification has been proposed to protect MNPs from issues such as oxidation, corrosion, or agglomeration, as well as to introduce functional groups. Currently, a variety of reactants, including APTES, [9][10][11][12][13] dopamine, [14][15][16] polyethyleneimine, [17] and 3,4-dihydroxybenzaldehyde [53] have been employed to modify MNPs. The most striking advantage of this tactic is that the introduction of functional groups such as NH 2 or COOH is conducive to induce the growth of COFs on the surface of MNPs, [18] resulting in a highly efficient combination of COFs with MNPs.…”

Harnessing an amide‐based covalent organic framework in solid‐phase extraction for chlorophenol analysis in industrial wastewaters

“…In recent years, nanostructure materials have gained increasing applications in analytical techniques and sample preparations, especially in SPE [19]. Among emerging nanostructure materials, covalent organic frameworks (COFs), are a class of multidimensional crystalline nanomaterials that are constructed from light elements such as C, H, O, B, Si, and N through reversible strong covalent bonds (C-C, C-O, C-Si, B-O, B-C, and C-N) [20][21][22]. COFs possess large specific surface areas, inherent porosity, homogeneous pore apertures, and exhibit high chemical and thermal stability.…”

Fabrication of highly crystalline covalent organic framework for solid‐phase extraction of three dyes from food and water samples

“…Recently, to meet the demand for the effective adsorption of dyes, many adsorbents such as graphene oxide, layered-double hydroxide nanomaterial, polyaniline-coated magnetite/silica materials, magnetic mesoporous polyimide composite, metalorganic frameworks (MOFs) and covalent organic frameworks (COFs) [19][20][21][22][23][24] have been manufactured. Particularly, ascribed to the advantages including adjustable pore sizes, large specific surface area, high chemical stability, and abundant functional group characteristics, COFs have become the focus of attention [25][26][27][28].…”