The extraction of four endocrine disrupters using hollow N-doped mesoporous carbon spheres with encapsulated magnetite (Fe 3 O 4 ) nanoparticles coupled to HPLC-DAD determination

Magnetite/hollow core–shell N-doped mesoporous carbon sphere (Fe 3 O 4 /N-HCSCs) composites were prepared as a sorbent for ultrasound-assisted magnetic solid-phase extraction of four endocrine disrupter compounds (EDCs) from water samples prior to the EDCs determination by high-performance liquid chromatography with a diode array detector (HPLC-DAD) (analytical wavelength, 260 nm). The Fe 3 O 4 /N-HCSCs, which contained N-HCSCs with encapsulated magnetite nanoparticles, were also characterized. The extraction and elution conditions were optimized by a one-factor-at-a-time approach using prepared Fe 3 O 4 /N-HCSCs for the selected the EDCs (triclosan, triclocarban, bisphenol A, and tetrabromobisphenol A bis(allyl)ether). Under the optimum extraction/elution conditions, the previously mentioned procedure achieved low detection limits (0.05–0.1 μg·L −1 ), high recovery values (88.0%–97.0%), satisfactory preconcentration factors (115–136), and good reproducibility (relative standard deviations of less than 5.8%, n  = 4). Kinetic and isotherm studies showed that the adsorption process followed pseudo-second-order kinetic and Freundlich equilibrium models. The Fe 3 O 4 /N-HCSCs had a good selectivity for the selected EDCs, mainly due to the large specific surface area of the sorbent, the presence of nitrogen species on the sorbent, and the hydrophobic interaction between the EDCs and sorbent. This work revealed the potential value of the method for rapidly screening EDCs in environmental water samples.