RESUMO
Core-shell magnetic Fe3O4@MIL-101(Cr) nanoparticles were synthesized via layer-by-layer self-assembly method. Using Fe3O4@MIL-101(Cr) as support, Fe3O4@MIL-101(Cr)@MIP was prepared with phenytoin as template, acrylamide as functional monomer, ethylene glycol dimethacrylate as cross-linker, methanol and acetonitrile as porogen, azoisobutyronitrile as initiator. The materials were characterized by a serious of characterization experiments. The prepared Fe3O4@MIL-101(Cr)@MIP was demonstrated to possess good separability, large adsorption capability, excellent adsorption selectivity, good durability and reusability via adsorption experiments. Subsequently, a magnetic solid phase extraction method (MSPE) based on Fe3O4@MIL-101(Cr)@MIP combined with high performance liquid chromatography-ultraviolet detector (HPLC-UV) was established for the determination of phenytoin sodium in plasma samples. Experimental parameters including pH, the amount of adsorbent, extraction time, elution conditions, the concentration of NaCl were investigated to optimize extraction process. The method was validated. The linearity was observed in the range of 0.05-40 µg mL-1 with a lower limit of quantification of 0.05 µg mL-1. The calibration equations were y = 0.2514x + 0.0319 (r2 = 0.9938), y = 0.2888x + 0.0472 (r2 = 0.9943), y = 0.2565x + 0.0418 (r2 = 0.9976), respectively. The recoveries ranged from 89.2 to 94.3%, intra- and inter-day precision (RSDs) ranged from 2.1 to 9.7% and 2.9-9.2%, respectively. The established MSPE-HPLC-UV method was time-saving, sensitive, accurate, environmental friendly, and drastically reduced the complex matrix interferences. The established method was successfully applied for phenytoin sodium determination in real plasma samples, providing new directions for therapeutic drug monitoring.
RESUMO
In this work, a variety of highly porous metal organic framework/chitosan (MOF/CS) foams (MIL-53(Al)/CS, MIL-53(Fe)/CS, MIL-101(Cr)/CS, MIL-101(Fe)/CS, UiO-66(Zr)/CS, and MIL-100(Fe)/CS) were designed and prepared by an ice-templating process. The introduction of MOFs made these foams achieve excellent inherent characters in terms of strength, stability, and adsorption ability. The MOFs incorporated in the foams retained their unique properties. Additionally, the foams were durable and their adsorption abilities had only a little loss after being recycled several times. MIL-53(Al)/CS foam was selected as an adsorbent candidate to develop an ultrasound-assisted solid-phase extraction (UA-SPE) method for the first time, owing to its particularly noteworthy performance among the prepared MOF/CS foams. The method was then successfully applied to extract trace amount of five parabens (methylparaben, ethylparaben, propylparaben, butylparaben, benzylparaben) in water samples, followed by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) detection. Several experimental parameters were investigated. Under the optimal conditions, the linear ranges were 0.5-200 µg/L with regression coefficients (r2) from 0.9948 to 0.9983. The method detection limits were between 0.09 and 0.45 µg/L. The recoveries ranged from 78.75 to 102.1% with relative standard deviations (RSDs) < 7.4%. Furthermore, the molecular interactions and free binding energies between MOFs and parabens were calculated by means of molecular docking to explain the adsorption mechanism deeply. The novel method proposed in this work exhibited many benefits such as easy operation, high enrichment efficiency, less solvent consuming, and higher sensitivity. Such a strategy would expand the application prospect of MOFs in sample pretreatment. Graphical abstract á .
