Enrichment of tetracycline residues from honey samples using carrier-mediated hollow fibre liquid-phase micro-extraction and quantification by LC-Q-TOF/MS

Fabrication of β-cyclodextrin-polyacrylamide/covalent organic framework hydrogel at room temperature for the efficient removal of triazole fungicides from environmental water

Triazole is frequently-used fungicide, which can leach into surface water through farmland and cause serious environmental pollution. Continuous exposure to triazole fungicides may cause harm to human health. Herein, β-cyclodextrin-polyacrylamide/covalent organic framework (β-CD-PAAM/TFPB-BD) hydrogel was fabricated at room temperature and used for the efficient removal of triazole fungicides. It displayed a short adsorption equilibrium time (50 min) and a total qe of 79.92 mg g-1. The adsorption process for triazole fungicides on β-CD-PAAM/TFPB-BD hydrogel conforms to the pseudo-second-order kinetic model and Freundlich model. The prepared hydrogel was recyclable and resistant to salt, high temperature, acid, and alkali. The reusability of fabricated sorbent can be achieved (i.e., five extraction cycles) for removal of target fungicides. Moreover, the β-CD-PAAM/TFPB-BD hydrogel was successfully applied to remove triazole fungicides in environmental water with removal efficiency ranging from 79.4% to 99.0%.

Magnetic covalent organic frameworks for rapid solid-phase extraction of phthalate esters and bisphenol A in beverage samples

Phthalate esters (PAEs) and bisphenol A (BPA) are endocrine-disrupting chemicals (EDCs), which are widely used in the production of food plastic packaging and easily migrate to food. Continuous exposure to EDCs may cause harm to human health. Herein, magnetic covalent organic framework TFP-NDA/Fe₃O₄ was synthesized by magnetizing covalent organic framework TFP-NDA through a facile coprecipitation method, and used as an adsorbent for rapid solid-phase extraction of PAEs (diethyl phthalate (DEP), diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP)) and BPA. The extraction equilibrium can be reached within 12 min. By combination with a gas chromatography-flame ionization detector, the limits of detection were 0.7-2.3 μg L^-1 and the linear ranges were 10-500 μg L^-1 for diethyl phthalate (DEP) and 10-1000 μg L^-1 for diisobutyl phthalate (DIBP), dibutyl phthalate (DBP) and BPA with R² > 0.9916. In beverage samples (plastic bottled drinking water, juice and carbonated drink), the developed method was successfully applied to extract and quantify PAEs and BPA with recoveries ranging from 81.7% to 114.2%.