In‐process prepared deep eutectic solvent based homogeneous liquid–liquid microextraction for the determination of irgaphos 168 and irganox 1010 in polypropylene packed drinks

In situ synthesis of a deep eutectic solvent and homogeneous liquid–liquid microextraction performed in a narrow bore tube was developed for efficient extraction of irgaphos 168 and irganox 1010 in doogh and water samples packed in polypropylene packages. First, pH of the aqueous sample solutions containing the analytes is adjusted at 9. Then a hydrogen bond acceptor (choline chloride) and a hydrogen bond donor (oleic acid) are dissolved in the solution and vortexed to obtain a homogeneous solution. The solution is filled into a narrow bore tube, in which its bottom was clogged by a septum. Then hydrochloric acid solution is injected into the solution by a syringe. The tube is placed in an ultrasonic bath. During this step, the droplets of choline chloride:oleic acid deep eutectic solvent are produced. The method indicated high enrichment factor (435 for irgaphos 168 and 488 for irganox 1010), low limits of detection (0.03 and 0.09 ng/mL for irgaphos 168 and irganox 1010, respectively) and quantification (0.13 and 0.29 ng/mL for irgaphos 168 and irganox 1010), good recovery (74 and 83% for irgaphos 168 and irganox 1010, respectively), and satisfactory repeatabilities (relative standard deviations ≤12%) can be obtained using the developed method.     

Genipin‐crosslinked gelatin hydrogel incorporated with PLLA‐nanocylinders as a bone scaffold: Synthesis,characterization, and mechanical properties evaluation

Nowadays, despite remarkable progress in developing bone tissue engineering products, the fabrication of an ideal scaffold that could meet the main criteria, such as providing mechanical properties and suitable biostability as well as mimicking the bone extracellular matrix, still seems challenging. In this regard, utilizing combinatorial approaches seems more beneficial. Here, we aim to reinforce the mechanical characteristics of gelatin hydrogel via a combination of Genipin‐based chemical cross‐linking and incorporation of the poly l ‐lactic acid (PLLA) nanocylinders for application as bone scaffolds. Amine‐functionalized nanocylinders are prepared via the aminolysis procedure and incorporated in gelatin hydrogel. The nanocylinder content (0, 1, 2, 3, and 4 wt%) and cross‐linking density (0.1, 0.5, and 1 wt/vol%) are optimized to achieve suitable morphology, swelling ratio, degradation rate, and mechanical behaviors. The results indicate that hydrogel scaffold cross‐linking by 0.5 wt% of Genipin shows optimized morphological feathers with a pore size of around 300 to 500 μm as well as an average degradation rate (40.09% ± 3.08%) during 32 days. Besides, the incorporation of 3 wt% PLLA nanocylinders into the cross‐linked gelatin scaffold provides an optimized mechanical reinforcement as compressive modulus, and compressive strength show a 4‐ and 2.6‐fold increase, respectively. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay indicates that the scaffold does not have any cytotoxicity effect. In conclusion, gelatin composite reinforced with 3 wt% PLLA nanocylinders cross‐linked via 0.5 wt/vol% Genipin is suggested as a potential scaffold for bone tissue engineering applications.     

Conformational Analysis of 2-Methoxy-2-oxo-1,3,2-dioxaphosphorinane and Its Methylthio and Methylselenyl Analogues

Russian Journal of Physical Chemistry A - This research aimed at exploring the stabilities of the conformers of 2-methoxy-2-oxo-1,3,2-dioxaphosphorinane and its methylthio and methylselenyl analogs...     

Ultrasound-assisted synthesis of novel spiro[indoline-3,5′-pyrido[2,3-d]pyrimidine] derivatives using Fe3O4@Propylsilane@Histidine[HSO4−] as an effective magnetic nanocatalyst

A simple, economical, three-component, and one-pot synthesis of novels spiro[indoline-3,5′-pyrido[2,3-d]pyrimidine] derivatives by condensation of dimethyl acetylene dicarboxylate, isatin derivatives, and 6-amino-1,3-dimethyluracil in presence of Fe₃O₄@Propylsilane@Histidine[HSO₄⁻] as an impressive catalyst via reflux and ultrasound procedure is described. The results show that ultrasound method has several advantages such as milder condition, shorter reaction time, and higher reaction yield.     

A Voltammetric Sensor Based on Spinel-Structured Copper Ferrite Nanoparticles Multiwalled Carbon Nanotubes Modified Carbon Paste Electrode for Determination of Dacarbazine

A simple and sensitive method was used to develop a novel sensor for determination of dacarbazine on the surface of multi-walled carbon nanotubes/CuFe₂O₄ nanoparticles modified carbon paste electrode (MWCNTs/CuFe₂O₄/CPE). Cyclic voltammetry, differential pulse voltammetry, chronoamperometry, and electrochemical impedance spectroscopy were used to investigate the electrochemical behavior of dacarbazine at the chemically modified electrode. According to the results, MWCNTs/CuFe₂O₄/CPE showed high electrocatalytic activity for dacarbazine oxidation, producing a sharp oxidation peak current at about +0.80 vs. Ag/AgCl reference electrode at pH 5.0. The peak current was linearly dependent on dacarbazine concentration over the range of 0.10–76.0 μmol L^–1 with the detection limit (3σ) of 0.08 μmol L^?1. In addition, chronoamperometry was also used to determine diffusion coefficient of dacarbazine at MWCNTs/CuFe₂O₄/CPE.     

Ultrasound-accelerated Synthesis of 1,4-Dihydropyridines in an Ionic Liquid

Summary. Hantzsch 1,4-dihydropyridine compounds were synthesized efficiently in high yields at room temperature within short times in 1,1,3,3-N,N,N′,N′-tetramethylguanidinium trifluoroacetate as ionic liquid using ultrasound irradiation. The ionic liquid can be recovered conveniently and reused efficiently.     

Synthesis of benzimidazole and quinoxaline derivatives using reusable sulfonated rice husk ash (RHA-SO3H) as a green and efficient solid acid catalyst

Research on Chemical Intermediates - In this work, a simple, rapid and efficient method for the preparation of benzimidazoles and quinoxalines from the condensation of o-phenylene diamines with...     

Design of Lead(II) Metal–Organic Frameworks Based on Covalent and Tetrel Bonding

Three solid materials, [Pb( HL )(SCN)₂] ? CH₃OH ( 1 ), [Pb( HL )(SCN)₂] ( 2 ), and [Pb( L )(SCN)]_n ( 3 ), were obtained from Pb(SCN)₂ and an unsymmetrical bis‐pyridyl hydrazone ligand that can act both as a bridging and as a chelating ligand. In all three the lead center is hemidirectionally coordinated and is thus sterically optimal for participation in tetrel bonding. In the crystal structures of all three compounds, the lead atoms participate in short contacts with thiocyanate sulfur or nitrogen atoms. These contacts are shorter than the sums of the van der Waals radii (3.04–3.47 Å for Pb ??? S and 3.54 Å for Pb ??? N) and interconnect the covalently bonded units (monomers, dimers, and 2D polymers) into supramolecular assemblies (chains and 3D structures). DFT calculations showed these contacts to be tetrel bonds of considerable energy (6.5–10.5 kcal mol^?1 for Pb ??? S and 16.5 kcal mol^?1 for Pb ??? N). A survey of structures in the CSD showed that similar contacts often appear in crystals of Pb^II complexes with regular geometries, which leads to the conclusion that tetrel bonding plays a significant role in the supramolecular chemistry of Pb^II.     

Application of spinel-structured MgFe<Subscript>2</Subscript>O<Subscript>4</Subscript> nanoparticles for simultaneous electrochemical determination diclofenac and morphine

The paper describes a sensitive method for simultaneous sensing of morphine (MOR) and diclofenac (DCF). The surface of a MgFe₂O₄/graphite paste electrode was modified with multi-walled carbon nanotubes, and the resulting sensor was characterized by cyclic voltammetry, differential pulse voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. The electrode showed an efficient synergistic effect in term of oxidation of DCF and MOR, with sharp oxidation peaks occurring at +0.370 and 0.540 V (vs Ag/AgCl) at pH 7.0. The calibration plot for MOR is linear in the 50 nM to 920 μM concentration range, and the detection limit is 10 nM (at a signal-to-noise ratio of 3). The respective data for DCF are 100 nM to 580 μM, with a 60 nM LOD. The sensor was applied to the determination of MOR and DCF in spiked serum and urine samples, with recoveries ranging between 91.4 and 100.7 %.

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Graphical abstract A sensitive method for simultaneous sensing of morphine (MOR) and diclofenac (DCF) is described. The surface of MgFe₂O₄/graphite paste electrode was modified with multi-walled carbon nanotubes, and the resulting sensor showed an efficient synergistic effect in terms of oxidation of DCF and MOR. The calibration plot for MOR is linear in the 50 nM to 920 μM concentration range, and the detection limit is 10 nM. The respective data for DCF are 100 nM to 580 μM, with a 60 nM LOD.

     

P<Subscript>4</Subscript>VPy–CuO nanoparticles as a novel and reusable catalyst: application at the protection of alcohols,phenols and amines

P₄VPy–CuO nanoparticles were synthesized using ultrasound irradiations. Relevant properties of the synthesized nanoparticles were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. After identification, the prepared reagent was used for the promotion of different types of protection reactions of alcohols, phenols and amines. Easy workup, short reaction times, excellent yields, relatively low cost and reusability of the catalyst are the striking features of the reported methods.