Metal–organic framework UiO-66 coated stainless steel fiber for solid-phase microextraction of phenols in water samples

Ordered mesoporous polymers in situ coated on a stainless steel wire for a highly sensitive solid phase microextraction fibre

Development of facile and effective methods for fabrication of high-performance solid phase microextraction (SPME) fibres remains a great challenge. Herein, a new class of ordered mesoporous polymers (OMPs) in situ coated on a stainless steel wire were successfully developed and utilized as a highly sensitive and stable SPME fibre for the first time. Because of the highly ordered mesoporous structure of its OMP coating, the π-π interactions and the dispersion forces, the OMP-coated SPME fibre exhibited much better extraction properties as compared to the commercial PDMS fibre. The findings could provide a new benchmark for preparing well-defined porous materials for the SPME application.

Recent advances in applications of nanomaterials for sample preparation

Sample preparation is a key step for qualitative and quantitative analysis of trace analytes in complicated matrix. Along with the rapid development of nanotechnology in material science, numerous nanomaterials have been developed with particularly useful applications in analytical chemistry. Benefitting from their high specific areas, increased surface activities, and unprecedented physical/chemical properties, the potentials of nanomaterials for rapid and efficient sample preparation have been exploited extensively. In this review, recent progress of novel nanomaterials applied in sample preparation has been summarized and discussed. Both nanoparticles and nanoporous materials are evaluated for their unusual performance in sample preparation. Various compositions and functionalizations extended the applications of nanomaterials in sample preparations, and distinct size and shape selectivity was generated from the diversified pore structures of nanoporous materials. Such great variety make nanomaterials a kind of versatile tools in sample preparation for almost all categories of analytes.

Metal-organic framework UiO-66 modified magnetite@silica core-shell magnetic microspheres for magnetic solid-phase extraction of domoic acid from shellfish samples

Fe3O4@SiO2@UiO-66 core-shell magnetic microspheres were synthesized and characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry, vibrating sample magnetometry, nitrogen adsorption porosimetry and zeta potential analyzer. The synthesized Fe3O4@SiO2@UiO-66 microspheres were first used for magnetic solid-phase extraction (MSPE) of domoic acid (DA) in shellfish samples. Combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a fast, simple and sensitive method for the determination of DA was established successfully. Under the optimized conditions, the developed method showed short analysis time, good linearity (r(2) = 0.9990), low limit of detection (1.45 pg mL(-1); S/N = 3:1), low limit of quantification (4.82 pg mL(-1); S/N = 10:1), and good extraction repeatability (RSD ≤ 5.0%; n = 5). Real shellfish samples were processed using the developed method, and trace level of DA was detected. The results demonstrate that Fe3O4@SiO2@UiO-66 core-shell magnetic microspheres are the promising sorbents for rapid and efficient extraction of polar analytes from complex biological samples.

Synthesis of a metal-organic framework confined in periodic mesoporous silica with enhanced hydrostability as a novel fiber coating for solid-phase microextraction

A metal-organic framework/periodic mesoporous silica (MOF-5@SBA-15) hybrid material has been prepared by using SBA-15 as a matrix. The prepared MOF-5@SBA-15 hybrid material was then deposited on a stainless-steel wire to obtain the fiber for the solid-phase microextraction of phenolic compounds. Modifications in the metal-organic framework structure have proven to improve the extraction performance of MOF/SBA-15 hybrid materials, compared to pure MOF-5 and SBA-15. Optimum conditions include an extraction temperature of 75°C, a desorption temperature of 260°C, and a salt concentration of 20% w/v. The dynamic linear range and limit of detection range from 0.1-500 and from 0.01-3.12 ng/mL, respectively. The repeatability for one fiber (n = 3), expressed as relative standard deviation, is between 4.3 and 9.6%. The method offers the advantage of being simple to use, rapid, and low cost, the thermal stability of the fiber, and high relative recovery (compared to conventional methods) represent additional attractive features.

Novel dextran/graphene oxide composite material as a sorbent for solid-phase microextraction of polar aromatic compounds

A novel dextran/graphene oxide-coated SPME fiber was prepared and used for extraction of phenols and halogenated aromatic compounds.

Isoreticular bio-MOF 100–102 coated solid-phase microextraction fibers for fast and sensitive determination of organic pollutants by the pore structure dominated mechanism

The stepwise ligand exchange strategy was successfully utilized for the improvement of adsorption ability of a series of bio-MOFs SPME fibers.