Preparation of molecular imprinted microspheres based on inorganic–organic co-functional monomer for miniaturized solid-phase extraction of fluoroquinolones in milk

Olefin Cross Metathesis as a Versatile Method for the Facile Functionalization of Porous Polymers

Olefin cross metathesis has been employed for the first time for the postpolymerization chemical modification of porous polymers. High quality microspheres of poly(divinylbenzene) were synthesized by the precipitation polymerization of divinylbenzene-55 in porogenic solvents, and the olefin cross metathesis reactions of the pendent (polymer-bound) vinyl groups not consumed by polymerization were performed with diverse coupling partners in dichloromethane using the Grubbs 2 catalyst, leading to microspheres decorated with a wide range of functional groups.

Fabrication of magnetic Fe3O4@nSiO2@mSiO2-NH2 core-shell mesoporous nanocomposite and its application for highly efficient ultrasound assisted dispersive µSPE-spectrofluorimetric detection of ofloxacin in urine and plasma samples

In this research, a sensitive, simple and rapid ultrasound assisted dispersive micro solid-phase extraction (USAD-µSPE) was developed using a synthesized core-shell magnetic mesoporous nanocomposite (Fe₃O₄@nSiO₂@mSiO₂-NH₂) as an efficient adsorbent for the preconcentration and spectrofluorometric determination of ofloxacin (OFL) in biological samples. The synthesized adsorbent was characterized using FT-IR spectroscopy, transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), energy dispersive X-ray (EDX) spectroscopy, thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) analysis. The application of this magnetic nanocomposite as a sensitive solid phase for removal, preconcentration and spectrofluorometric quantification of trace amount of OFL was developed. Influence of various variables including pH, sorbent dosage, desorption solvent properties and sonication time on present method response was studied and optimized. The results showed that using the proposed method OFL can be determined in the linear concentration range of 1.0-500.0µgL^-1 with a limit of detection as low as 0.21µgL^-1 and relative standard deviation less than 2.5 (%). The results of human urine and blood plasma analysis showed that the method is a good candidate for biological sample analysis purposes.

Synthesis of Sponge-Like Material for the Extraction of Fluoroquinolones in Milk

The new sponge material was prepared by the copolymerization of polystyrene and methacrylic acid. The polystyrene seed was prepared by two-step seed swelling polymerization. Scanning electron microscopy images showed that the sponge material were clumps with porous morphologies. The adsorption behaviour of the sponge material was analysed by detecting pefloxacin and enfloxacin in milk samples. Under the optimized conditions, good linearity was obtained in the range 0.05-10.0 μg g−1, with a correlation coefficient (r2) of ≥ 0.9991. The recoveries at three spiking levels ranged from 85.6 to 106.9% with relative standard deviations (RSDs) of ≤6.6%. The sponge material could be applied to the rapid screening of Pefloxacin and enfloxacin in complicated milk-product matrices.