Multi‐walled carbon nanotube modified dummy‐template magnetic molecularly imprinted microspheres as solid‐phase extraction material for the determination of polychlorinated biphenyls in fish

Abstract

Novel multi-walled carbon nanotube modified dummy-template molecularly imprinted microspheres (MWCNTs@DMMIPs) were successfully synthesized as adsorbents for six kinds of polychlorinated biphenyls (PCBs). MWCNTs@DMMIPs were prepared by a surface molecular imprinting technique. Core-shell Fe3 O4 @SiO2 nanoparticles were employed as magnetic support. 3,4-Dichlorobenzene acetic acid was used as a dummy template instead of PCBs, methacrylic acid was used as functional monomer and ethylene glycol dimethacrylate was used as the cross-linker. The resulting absorbent was characterized by various methods. The adsorbent was employed for extracting PCBs and exhibited good selectivity and high adsorption efficiency. Furthermore, it was reusable and capable of magnetic separation. Adsorption kinetics fit well with a pseudo-second-order kinetic equation and also exhibited a three-stage intra-particle diffusion model. The Freundlich model was used to describe the adsorption isotherms. The materials were successfully applied to the magnetic dispersive solid-phase extraction of six kinds of PCBs followed by gas chromatography with mass spectrometry determination in fish samples, the limit of detection of six kinds of PCBs were 0.0028-0.0068 μg/L and spiked recoveries ranged between 73.41 and 114.21%. The prepared adsorbent was expected to be a new material for the removal and recovery of PCBs from contaminated foods.

Rapid preparation of methyltrimethoxy‐modified magnetic mesoporous silica as an effective solid‐phase extraction adsorbent

“…The calculated adsorbed amount q 2 and rate constant k 2 for the pseudo second‐order model were 0.506 mg/g and 1.5 g/mg/min, respectively. The sorption rate of the prepared material was higher than the previous reports .…”

Separation and enrichment of six indicator polychlorinated biphenyls from real waters using a novel magnetic multiwalled carbon nanotube composite absorbent

“…The magnetic Fe 3 O 4 particles were prepared according to our previously reported synthetic process . The Fe 3 O 4 @SiO 2 nanospheres were prepared according to the previously reported sol–gel method . Briefly, 0.5 g of dry Fe 3 O 4 particles were firstly pretreated with 0.1 M HCl aqueous solution (100 mL) by ultrasonication for 15 min.…”

Solid‐phase nanoextraction of polychlorinated biphenyls in water and their determination by gas chromatography with electron capture detector

“…Numerous approaches based on LLE and SPE have been successfully applied for determination of PCBs at trace levels [12][13][14][15][16]. In this field, some attempts have been made on the basis of SPME, in which some adsorbent materials such as graphene-based fibers [17,18], singlewalled carbon nanotubes (SWCNT), and multiwalled carbon nanotubes (MWCNT) [19] have been utilized. Some methods have been reported to minimize the sample or solvent requirements, and 2D GC or LC [20][21][22][23] with appropriate detectors are used for analysis.…”