Covalent organic framework and montomorillonite nanocomposite as advanced adsorbent: synthesis, characterization, and application in simultaneous adsorption of cationic and anionic dyes.

In this work, Schiff base network-1 (SNW-1), as a new generation of covalent organic frameworks (COFs), was synthesized and modified by fabrication of a composite with clay mineral montomorillonite (Mt). It was used for simultaneous removal of anionic and cationic dyes from aqueous solutions. The fabricated composite was characterized successfully with various techniques.

Developing a novel packed in-tube solid-phase extraction method for determination 9-tetrahydrocannabinol in biological samples and cannabis leaves.

A novel plate-like nano-sorbent based on copper/cobalt/chromium layered double hydroxide was synthesized by a simple coprecipitation method. The synthesized nanoparticels were introduced into a stainless steel cartridge using a dry packing method. Then, the packed cartridge was introduced as a novel on-line "packed in-tube" configuration and followed by high performance liquid chromatography for the determination of trace amounts of 9-tetrahydrocannabinol from biological samples and cannabis leaves.

Chitosan-based sorbent for efficient removal and extraction of ciprofloxacin and norfloxacin from aqueous solutions.

Nanosheets prepared from magnesium oxide, chitosan and graphene oxide (MgO/Chit/GO) were hydrothermally synthesized and used as a sorbent for removal of ciprofloxacin and norfloxacin from aqueous solutions. Residual antibiotics in sample were determined by HPLC/UV instrument. The sorbent was characterized by FTIR, XRD, BET, SEM, and TEM.

Synthesis and characterization of a novel biocompatible pseudo-hexagonal NaCa-layered double metal hydroxides for smart pH-responsive drug release of dacarbazine and enhanced anticancer activity in malignant melanoma.

Layered metal hydroxides have exhibited remarkable benefits in drug delivery, days or even weeks of continuous drug release with improved bioavailability and minimized adverse effects. Here, we report synthesis of a new M (Na) and M (Ca) layered double metal hydroxide-based phases with the general formula of [NaCa(OH)] (NO), and 3D pseudo-hexagonal morphology. NaCa layered double metal hydroxide (NaCa-LDH), which is biodegradable, biocompatible, and pH-sensitive, could have broad applicability in drug release and other biomedical applications.

A metal organic framework prepared from benzene-1,3,5-tricarboxylic acid and copper(II), and functionalized with various polysulfides as a sorbent for selective sorption of trace amounts of heavy metal ions.

Novel composites were obtained via direct assembly of polysulfides (S, X = 3, 4, 6) on the surface of a metal organic framework (MOF; type benzene-1,3,5-tricarboxylic/Cu(II). They are referred to as S-MOFs and were used for highly selective and efficient extraction of ultra-trace amounts of heavy metal ions from aqueous solutions. The structure of the S-MOFs was characterized by Raman spectroscopy, FT-IR, X-ray diffraction, and scanning electron microscopy.

One-step synthesis of FePtPd(OH)[Picolinic acid](HO) hybrid nanorods: efficient and stable electrocatalyst for oxygen reduction reaction in alkaline solution.

Design and synthesis of effective electrocatalysts for oxygen reduction reaction in alkaline environments is critical to reduce energy losses in alkaline fuel cells. We have systematically evaluated new approaches for reducing the Pt content while retaining the activity of a Pt-based catalyst with hydrolytic phases containing hydroxide moieties in addition to metal ions and ligands. We report for the first time architectured organic-inorganic hybrid nanorod catalyst, which is fabricated by solvothermal reaction of KMCl (M = Pd, Pt) with picolinic acid (PA) (chelating agent) in the presence of FeCl.

Evaluation of highly efficient on-line yarn-in-tube solid phase extraction method for ultra-trace determination of chlorophenols in honey samples.

In this study a novel "yarn-in-tube" configuration was introduced by packing cotton yarn inside stainless steel cartridge named packed yarn-in-tube solid phase extraction (yarn-IT-SPE) followed by high performance liquid chromatography. For the first time, cotton yarns were coated with a new polypyrrole@copper-chromium-iron ternary layered double hydroxide nanocomposite (Yarn@PPy@Cu-Cr-Fe LDH). The yarn@PPy@Cu-Cr-Fe LDH sorbent exhibited flexible substrate, high porosity, a three-dimensional, high sorbent loading, long lifetime, good mechanical stability, high anion-exchange capacity and large specific surface area as a result it is a good choice for the separation and preconcentration of acidic cholorophenols in honey samples.

Electrochemically controlled fiber-in-tube solid-phase microextraction method for the determination of trace amounts of antipsychotic drugs in biological samples.

In this study, a novel 'fiber-in-tube' configuration was applied to electrochemically controlled fiber-in-tube solid-phase microextraction of antipsychotic drugs (perphenazine and chlorpromazine) from biological samples. To prepare an electrochemically controlled fiber-in-tube solid-phase microextraction column, first eight stainless-steel wires were placed into the stainless-steel column. Then, a nanostructured Cu-Cr-Al ternary layered double hydroxide/polythiophene coating was prepared on the inner surface of the stainless-steel tube and on the surfaces of the stainless-steel wires by a facile in situ electrodeposition method.

Fabrication of zwitterionic histidine/layered double hydroxide hybrid nanosheets for highly efficient and fast removal of anionic dyes.

In this work, the bio-nanohybrids of magnesium-aluminum layered double hydroxide intercalated with zwitterionic histidine (His-LDH) was synthesized. The crystal phase, morphology, and nanostructure of the as-prepared His-LDH were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption-desorption methods. The His-LDHs were used to remove anionic dyes, including Congo red (CR), indigo carmine (IC) and sunset yellow FCF (SY) from aqueous solutions.

Functionalized layered double hydroxide with nitrogen and sulfur co-decorated carbondots for highly selective and efficient removal of soft Hg and Ag ions.

A facile composite was fabricated via direct assembly of nitrogen and sulfur co-decorated carbon dots with abundant oxygen-containing functional groups on the surface of the positively charged layered double hydroxide (N,S-CDs-LDH). The novel N,S-CDs-LDH demonstrates highly selective bindings (M-S) and an extremely efficient removal capacity for soft metal ions such as Ag and Hg ions. N,S-CDs-LDH displayed a selectivity order of Ag> Hg >> Cu >>> Pb > Zn > Cd for their adsorption.

Development of electrochemically controlled packed-in-tube solid phase microextraction method for sensitive analysis of acidic drugs in biological samples.

In the present research, for the first time, a novel "packed-in-tube" configuration has been applied to electrochemically controlled in-tube solid phase microextraction, followed by high performance liquid chromatography. In order to prepare a mini packed column, small beads of stainless steel were first placed into the stainless steel column. Then, a nanostructured polypyrrole film was prepared on the internal surface of a stainless steel tube and the surface of stainless steel particles through a facile in-situ electrodeposition method.

Multiwall carbon nanotube- zirconium oxide nanocomposite hollow fiber solid phase microextraction for determination of polyaromatic hydrocarbons in water, coffee and tea samples.

The purpose of this study was to evaluate the application of hollow fiber solid-phase microextraction (HF-SPME) followed by HPLC-UV to determine the ultra-trace amounts of polycyclic aromatic hydrocarbons (PAHs) as model analytes in complex coffee and tea samples. HF-SPME can be effectively used as an alternative to the direct immersion SPME (DI-SPME) method in complex matrices. The DI-SPME method suffers from serious limitation in dirty and complicated matrices with low sample clean-up, while the HF-SPME method has high clean-up and selectivity due to the high porosity of hollow fiber that can pick out analyte from complicated matrices.

On-line packed magnetic in-tube solid phase microextraction of acidic drugs such as naproxen and indomethacin by using FeO@SiO@layered double hydroxide nanoparticles with high anion exchange capacity.

The authors describe a 3-component nanoparticle system composed of a silica-coated magnetite (FeO) core and a layered double (Cu-Cr) hydroxide nanoplatelet shell. The sorbent has a high anion exchange capacity for extraction anionic species. A simple online system, referred to as "on-line packed magnetic-in-tube solid phase microextraction" was designed.

A nanocomposite prepared from a polypyrrole deep eutectic solvent and coated onto the inner surface of a steel capillary for electrochemically controlled microextraction of acidic drugs such as losartan.

The authors describe a new coating for use in electrochemically controlled in-tube solid phase microextraction (EC-IT-SPME). It consists of a nanocomposite that was prepared from polypyrrole and deep eutectic solvent (DES) by electrochemical deposition on the inner walls of a stainless steel capillary that serves as a working electrode. The hypertension drug losartan acts as an acidic model analyte.

Highly selective and efficient removal of arsenic(V), chromium(VI) and selenium(VI) oxyanions by layered double hydroxide intercalated with zwitterionic glycine.

In this study, a new strategy for highly selective and extremely efficient removal of toxic oxyanions (Cr(VI), Se(VI), and As(V)) from aqueous solutions using zwitterionic glycine intercalated layered double hydroxide (Gly-LDH) was reported. Hence, to investigate the effect of zwitterionic glycine on the adsorption capacity, selectivity factor and adsorption mechanism of LDHs, two NiAl LDHs intercalated with different inter-layer anions, including NO and glycine, were synthesized. The obtained results show that the adsorption capacity and selectivity factor of oxyanions through ion exchange mechanism in NO-LDH is lower than Gly-LDH.

Polythiophene/graphene oxide nanostructured electrodeposited coating for on-line electrochemically controlled in-tube solid-phase microextraction.

In this work, a novel polythiophene/graphene oxide (PTh/GO) nanostructured coating was introduced for on-line electrochemically-controlled in-tube solid phase microextraction of amitriptyline (AMI) and doxepin (DOX) as antidepressant drugs. The PTh/GO coating was prepared on the inner surface of a stainless steel tube by a facile in-situ electro-deposition method and it was used as a working electrode for electrochemically control in-tube solid phase microextraction. In the PTh/GO coating, GO acts as an anion dopant and sorbent.

On-line electrochemically controlled in-tube solid phase microextraction of inorganic selenium followed by hydride generation atomic absorption spectrometry.

In this work, for the first time, a rapid, simple and sensitive microextraction procedure is demonstrated for the matrix separation, preconcentration and determination of inorganic selenium species in water samples using an electrochemically controlled in-tube solid phase microextraction (EC-in-tube SPME) followed by hydride generation atomic absorption spectrometry (HG-AAS). In this approach, in which EC-in-tube SPME and HG-AAS system were combined, the total analysis time, was decreased and the accuracy, repeatability and sensitivity were increased. In addition, to increases extraction efficiency, a novel nanostructured composite coating consisting of polypyrrole (PPy) doped with ethyleneglycol dimethacrylate (EGDMA) was prepared on the inner surface of a stainless-steel tube by a facile electrodeposition method.

Preparation and evaluation of a novel molecularly imprinted polymer coating for selective extraction of indomethacin from biological samples by electrochemically controlled in-tube solid phase microextraction.

In the present work, an automated on-line electrochemically controlled in-tube solid-phase microextraction (EC-in-tube SPME) coupled with HPLC-UV was developed for the selective extraction and preconcentration of indomethacin as a model analyte in biological samples. Applying an electrical potential can improve the extraction efficiency and provide more convenient manipulation of different properties of the extraction system including selectivity, clean-up, rate, and efficiency. For more enhancement of the selectivity and applicability of this method, a novel molecularly imprinted polymer coated tube was prepared and applied for extraction of indomethacin.

Electroplating of nanostructured polyaniline-polypyrrole composite coating in a stainless-steel tube for on-line in-tube solid phase microextraction.

In this work, a novel and efficient on-line in-tube solid phase microextraction method followed by high performance liquid chromatography was developed for preconcentration and determination of trace amounts of parabens. A nanostructured polyaniline-polypyrrole composite was electrochemically deposited on the inner surface of a stainless steel tube and used as the extraction phase. Several important factors that influence the extraction efficiency, including type of solid-phase coating, extraction and desorption times, flow rates of the sample solution and eluent, pH, and ionic strength of the sample solution were investigated and optimized.

Ultrasound-assisted liquid-phase microextraction based on a nanostructured supramolecular solvent.

Novel ultrasonically enhanced supramolecular solvent microextraction (USESSM) then high-performance liquid chromatography with ultraviolet detection have been used for extraction and determination of phthalates in water and cosmetics. Coacervates consisting of decanoic acid-based nano-structured aggregates, specifically reverse micelles, have been used the first time as solvents for ultrasound-assisted emulsification microextraction (USAEME). Sonication accelerated mass transfer of the target analytes into the nano-structured solvent from the aqueous sample, thus reducing extraction time.