Synthesis of magnetic metal organic framework/covalent organic framework hybrid materials as adsorbents for magnetic solid‐phase extraction of four endocrine‐disrupting chemicals from milk samples

Abstract

Rationale Endocrine‐disrupting chemicals (EDCs), widespread and easily ingested through the simple food chain, have been suggested to pose potential carcinogenic threats to human health. Considering food safety and public health, it is urgent to establish a sensitive and effective method to enrich and determine EDCs in food samples. Methods Novel hybrid nanocomposites Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) were synthesized through the formation of amide bonds. The as‐prepared Fe3O4 were innovatively encapsulated with 4‐aminobenzoic acid functionalized COF(A‐TpBD) to generate bare carboxyl (‐COOH), which formed amide bonds with the NH2‐MIL‐125(Ti), generating well‐defined and hierarchical hybrid materials. The Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) materials were used as the adsorbents for magnetic solid‐phase extraction (MSPE) coupled with high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) to enrich and determine EDCs (E1, E2, E3 and BPA) from milk samples. Results Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) exhibited improved adsorption efficiency and selectivity based on π‐π stacking interaction, hydrogen bonding, electrostatic interaction, and the interaction between the hydroxyl group in EDCs and titanium ions (IV, [Ti]4+). Under the optimized conditions, Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti)‐based MSPE coupled with HPLC/MS/MS showed good linearity with correlation coefficient (R2) ≥0.9983 and high sensitivity with limits of detection (LODs) in the range of 0.37–0.85 μg/L. Moreover, the developed method was successfully employed to detect EDCs in milk samples. Conclusions Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) possess good adsorption capability and selectivity for EDCs. In addition, the proposed MSPE‐HPLC/MS/MS method based on Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) is effective and sensitive for the determination of EDCs in real samples, which can be used as a robust alternative method to monitor EDCs in complex matrices.

Combining metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs): Emerging opportunities for new materials and applications

“…For instance, Farha and co-workers [97] reported the introduction of hydrophobic phenylacetylene into NU-401 via the addition reaction of imine bonds. As-obtained NU-401-Q remained an oxygen uptake up to 8.8 mol•kg −1 comparable to that of HKUST-1 [151], but more significantly showed much improved water resistance for maintaining long-term performance ability. As a proof of concept, more than 75% of the surface area of NU-401-Q was retained while NU-401 completely lost its porosity, after immersing NU-401 and NU-401-Q in deionized water for 20 h.…”

Composite materials based on covalent organic frameworks for multiple advanced applications

“…[ 83 ] Table 2 lists the representative applications of COFs‐metal oxides in magnetic solid‐phase extraction (MSPE). [ 101–111 ]…”

“…[83] Table 2 lists the representative applications of COFs-metal oxides in magnetic solid-phase extraction (MSPE). [101][102][103][104][105][106][107][108][109][110][111] In the above examples, most of them make use of Fe 3 O 4 as the carrier to build a magnetic COFs for MSPE. For example, Fe 3 O 4 @TbBd nanobeads as a new MSPE extractant can selectively isolate and enrich trace amounts of estrogens from human urine samples.…”

Integration of metal-organic frameworks and covalent organic frameworks: Design, synthesis, and applications

“…74 In addition to the above examples, the MOF/COF composites have also been used as solid-phase sorbents for sulfonamides, sedatives, among others, providing an attractive platform for the concentration and detection of pollutants in practical samples. [75][76][77] Optics and sensing Detection of toxic, hazardous, or valuable chemical species is extremely important to maintain human health and avoid the recent threat from environmental pollution. Therefore, the development of advanced sensor materials and effective detection methods for monitoring these chemicals are highly necessary.…”