Simultaneous analysis of eight phenolic environmental estrogens in blood using dispersive micro-solid-phase extraction combined with ultra fast liquid chromatography–tandem mass spectrometry

Preparation of sheet-like covalent organic frameworks and their application for efficient preconcentration of 4-(tert-octyl)-phenol and 4-nonylphenol in textiles

In the design of highly ordered (covalent organic frameworks) COFs with "ordered domains size and orientation" construction in a well-defined arrangement, the molecular monomers are the key factors. Here, the effect of molecular monomers on the construction of COFs has been studied, and two kinds of molecular monomers, i.e., ethanediamine (flexible amine ligand) and 4,4'-diaminobiphenyl (rigid amine ligand) have been used for developing sheet-like COFs-I and sheet-like COFs-II, respectively. Furthermore, they have been evaluated in the dispersive solid phase extraction (dSPE) procedure for textiles prior to the analysis of alkylphenol by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). The results showed that, the optimal usage amount of sheet-like COFs-II used in the dSPE procedure was less than that of sheet-like COFs-I, which may be explained by much higher adsorption capacity of sheet-like COFs via hydrogen-bonding and π-π stacking interactions. Rectilinear calibration graphs were obtained for 4-(tert-octyl)-phenol (4-tOP) and 4-nonylphenol (4-NP) in the range 0.2-20 µg/kg with determination coefficient (r²) higher than 0.9990, and the limits of detection (LODs) of 4-tOP and 4-NP were 0.039 µg/kg and 0.048 µg/kg, respectively. The developed method has been successfully applied to analysis of 50 textile samples, in which 4-tOP and 4-NP were found in six samples with concentrations in the range of 1.6 μg/kg-20.9 μg/kg.

A novel technique for simultaneous determination of drugs using magnetic nanoparticles based dispersive micro-solid-phase extraction in biological fluids and wastewaters

In this study, a novel method was developed to measure acidic and basic drugs in biological and wastewater samples. The method used magnetic nanoparticles based on Vortex-Assisted Dispersive Micro-Solid Phase Extraction (SPE) and then identifying with HPLC-UV. The magnetic nanoparticle (Fe₃O₄@SiO₂@Kit-6@NH₂) has been used as an efficient adsorbent for the extraction of acidic and basic drugs ibuprofen (IFB), fenoprofen calcium (FPC), methocarbamol (MTC), and clonazepam (CZP). The magnetic nanoparticle was characterized by techniques including SEM, XRD, EDX, and FT-IR. The effect of various parameters in the V-D-μ-SPE method was studied completely through the design of the response surface methodology (RSM) of the Box–Behnken design (BBD) based response method and the utility function. The parameters affecting the extraction efficiency were optimized including sample pH, adsorbent amount, absorption time, the salt concentration in the sample solution, CTAB of concentration, desorption time, and the volume of an eluent. After optimization, the limit of detection and calibration curve in the linear range were obtained 0.062–0.32 μg L⁻¹ and 0.1–800 μg L⁻¹, respectively. Its linear correlation was R²> 0.9951. The relative standard deviation (n = 5) was between 2.4% and 5.1%. Finally, this method was used to determine target analytes in human serum, urine, and wastewater.•

In this study, for the first time, a novel method for the determination of some drugs from human serum, urine, and wastewater samples.

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The Synthesized Fe₃O₄@SiO₂@Kit-6@NH₂ NPs based V-D-μ-SPE was characterized by techniques including SEM, XRD, EDX, and FT-IR.

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The effects of various parameters in the V-D-μ-SPE methods were studied through the design of the RSM of BBD.

Detection of four phenolic oestrogens by a novel electrochemical immunosensor based on a hexestrol monoclonal antibody

A novel HEX monoclonal antibody/MACA/nanogold electrochemical immunosensor was constructed to detect four phenolic oestrogens by a nanosized effect, layer by layer self-assembly and antigen–antibody specific immune technology.

Determination of chlorophenoxy acid herbicides by using a zirconium-based metal–organic framework as special sorbent for dispersive micro-solid-phase extraction and high-performance liquid chromatography

This study reports a Zr-based MOF with 2-amino-benzenedicarboxylic acid ligand as an adsorbent for chlorophenoxy acid herbicides from biosamples.

Vortex-Assisted Dispersive Micro-Solid Phase Extraction Using CTAB-Modified Zeolite NaY Sorbent Coupled with HPLC for the Determination of Carbamate Insecticides

A vortex-assisted dispersive micro-solid phase extraction (VA-D-μ-SPE) based on cetyltrimethylammonium bromide (CTAB)-modified zeolite NaY was developed for preconcentration of carbamate pesticides in fruits, vegetables, and natural surface water prior to analysis by high performance liquid chromatography with photodiode array detection. The small amounts of solid sorbent were dispersed in a sample solution, and extraction occurred by adsorption in a short time, which was accelerated by vortex agitation. Finally, the sorbents were filtered from the solution, and the analytes were subsequently desorbed using an appropriate solvent. Parameters affecting the VA-D-μ-SPE performance including sorbent amount, sample volume, desorption solvent ,and vortex time were optimized. Under the optimum condition, linear dynamic ranges were achieved between 0.004-24.000 mg kg(-1) (R(2) > 0.9946). The limits of detection (LODs) ranged from 0.004-4.000 mg kg(-1). The applicability of the developed procedure was successfully evaluated by the determination of the carbamate residues in fruits (dragon fruit, rambutan, and watermelon), vegetables (cabbage, cauliflower, and cucumber), and natural surface water.

Magnetic molecularly imprinted polymers–silver nanoparticle based micro-solid phase extraction for the determination of polycyclic aromatic hydrocarbons in water samples

In this study, an efficient and sensitive magnetic molecularly imprinted polymer–silver nanoparticle (MMIPS) system was successfully synthesized.

Application of Ni:ZnS nanoparticles loaded on magnetic multi-walled carbon nanotubes as a sorbent for dispersive micro-solid phase extraction of phenobarbital and phenytoin prior to HPLC analysis: experimental design

Ni:ZnSNPs loaded on magnetic MWCNTs are introduced for dispersive micro-solid phase extraction for the first time.

Comparison between dispersive liquid–liquid microextraction and ultrasound-assisted nanoparticles-dispersive solid-phase microextraction combined with microvolume spectrophotometry method for the determination of Auramine-O in water samples

Novel dispersive solid phase micro-extraction and dispersive liquid–liquid micro-extraction determination of Auramine-O content in various real samples.

Rapid determination of memantine in human plasma by using nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer d-μ-SPE and UFLC-MS/MS

A novel, simple, and sensitive method based on the use of dispersive micro-solid-phase extraction (d-μ-SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the determination of memantine (ME) was developed and validated over the linearity range 0.05-10.0 µg/L with 100 μL of human plasma using memantine-D6 (ME-D6) as the internal standard. The novel nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer (NR-CF-Mag-MIP) was synthesized by ultrasound-assisted suspension polymerization, using ME as a template molecule, methacrylic acid as a functional monomer, and divinylbenzene as a cross-linking agent. The NR-CF-Mag-MIP was used as the d-μ-SPE sorbent to extract ME from human plasma samples. The obtained results demonstrated the higher extraction capacity of NR-CF-Mag-MIP with recoveries between 97.6 and 101%. The limits of quantification (LOQs) for ME was 0.015 µg/L. Validation results on linearity, specificity, accuracy, precision, and stability, as well as on application to the analysis of samples taken up to 480 h after oral administration of 20 mg (two 10 mg capsules) of ME in healthy volunteers demonstrated the applicability to bioequivalence studies.