Chemical Papers最新文献

Herein, we present a new eco-friendly microextraction method based on the magnetite/multi-walled carbon nanotubes reinforced and natural deep eutectic-filled hollow fiber solid/liquid phase microextraction, abbreviated as HF-SLPME, combined with HPLC–DAD analysis. This method has been developed to determine trace levels of phthalate esters, including diethyl phthalate, benzyl butyl phthalate, and di-iso-butyl phthalate in urine, blood plasma, tap water, and groundwater samples. The natural deep eutectic solvents were prepared using terpenoid-derived natural compounds containing menthol and camphor in various ratios. The HF-SLPME device was constructed by reinforcing and immobilizing the synthesized Fe₃O₄-MWCNTs within the pores of a 2.5 cm segment of hollow fiber microtube through ultrasonication, followed by filling the lumen with the natural deep eutectic solvent with both ends heat sealing. The extraction process was conducted in direct immersion mode. Values of crucial variables for HF-SLPME were optimized through a multivariate methodology based on a central composite design, with 30 extraction tests performed to determine the best conditions. The method exhibited good linearity (correlation coefficients R² > 0.996) over a dynamic range lower than 0.927–10³ µg L⁻¹. The results show that the limits of detection/quantification for the chosen PEs ranged from 0.19 to 0.27/ 0.65 to 0.92 µg L⁻¹ with enrichment factor˃ 37.24. As evidenced by intra- and inter-day precisions, satisfactory reproducibility was achieved with relative standard deviations (RSDs) below 3.7% and 5.1%, respectively. The recoveries of the selected phthalate esters from spiked real samples ranged from 88.4 to 111.1%, with relative standard deviations between 2.3 and 6.5%. This HF-SLPME-HPLC–DAD method offered a new, cost-effective, sensitive microextraction approach for determining and quantifying phthalate esters in aqueous samples with complex matrices.

The use of reverse osmosis (RO) for desalination holds great promise for addressing water scarcity issues in many parts of the world. However, membrane fouling is a significant impediment in this regard, as it reduces the quality and quantity of water produced, increases energy consumption, requires cleaning, and shortens membrane life. The use of granular activated carbon (GAC) adsorption in conjunction with ultrafiltration (UF) as a pre-treatment ensures that high-quality seawater enters the desalination process free of contaminants that could harm the plant. This method increases the efficiency and longevity of the equipment, lowers maintenance costs, and produces high-quality desalinated water for a variety of applications. In this study, GAC was made from commercially available charcoal and used to remove organic compounds, heavy metals, and microbiological contaminants from seawater. A preliminary study was conducted to determine GAC’s effectiveness in removing methylene blue (MB). The removal efficiency was found to be 78 and 99% at initial MB concentrations of 50 and 10 mg/L, respectively. The isotherm modeling confirms that the adsorption process follows the Langmuir model. In addition, the kinetic study demonstrated that MB adsorption on GAC follows the pseudo-second-order model. GAC filtration removed more than 99% of COD and significantly reduced metal concentrations such as Zn, Cu, and Cd. Bacteriological analysis of seawater treated with GAC revealed a significant reduction in total and fecal coliforms, as well as fecal streptococci, indicating the efficacy of the GAC/adsorption filtration system.

In general, the pollutants can be sequestrated from wastewater by adsorption technology under batch or continuous flow conditions. Although there are a good number of reviews on pollutants uptake under batch conditions and related operational factors affecting the process, reviews on pollutants uptake under column conditions are relatively few. Hence, the importance of this review comes as it evaluated the performance of many adsorbents under continuous flow conditions, which is considered more practical than batch process. Based on this aim, many synthetic and non-conventional adsorbents were examined which utilized for dyes uptake under batch and continuous flow conditions. It is necessary to assess the performance of the examined adsorbents using both processes to determine the most appropriate one, taking into account the high production cost of synthetic adsorbents. The performance of sixty nine adsorbents for removing different classes of dyes using batch and column type processes are examined in this review. The results are collected under the following criteria: (a) The adsorbent should have maximum uptake capacity higher than 100 mg g⁻¹; (b) Column saturation capacity, operational factors and service time for dye uptake are reported; (c) Adsorbent recycling under dynamic conditions is reported. Based on the earlier criteria a screening guide was proposed for the most efficient dye adsorbent under column conditions: (a) column saturation capacity > 184 mg g⁻¹; (b) column service time < 10 h; (c) the adsorbent should be used up to 5 cycles after regeneration with a green solvent. The most efficient synthetic adsorbent is vinylpyridine-methacrylic acid cryogel toward Basic Blue 9 with column capacity 388 mg g⁻¹, service time 0.8 h and used for 4 cycles with 100% efficiency. For non-conventional adsorbents, modified-chitosan is outstanding toward Basic Blue 9 with column capacity 379 mg g⁻¹, service time 3.4 h and used for 5 cycles with a final efficiency 93%.

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Zirconium dioxide nanoparticles (ZrO₂ NPs) were synthesized using simple, lucrative and easily scalable flame pyrolysis method by directly burning the precursor solution in air. ZrO₂ NPs were collected in the form of white soot one from cold surface of conical Flask (F-ZrO₂ NPs) and another from direct crucible (C-ZrO₂ NPs). The synthesized ZrO₂ NPs were characterized by various techniques viz., Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), UV–vis absorption spectroscopy, Energy Dispersive X-ray Spectroscopy (EDS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), High Resolution Transmission Electron Microscopy (HR-TEM). The synthesised ZrO₂ NPs demonstrated the monoclinic (m-ZrO₂) and tetragonal (t-ZrO₂) mixed phases with an average crystalline size of 16.96 nm. The morphological analysis elucidated the uniform distribution of spherically shaped ZrO₂ NPs. The dye degradation performance of synthesized nanoparticles was experienced for the complexed structured Methylene Blue (MB) azo dye meant for environmental applications. The synthesized nanoparticles demonstrated excellent dye removal efficiency of 97.90% along with successful reusability up to six cycles for removal of aqueous Methylene Blue (MB) hazardous colorant dye. So, the synthesised ZrO₂ NPs designated as finest contender for the wastewater treatment and various environmental applications.

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Considering the dramatic health and economic period that the world experienced during the COVID-19 pandemic, finding new drugs for the treatment of this disease is still a great scientific concern. Favipiravir (6-fluoro-3-hydroxypyrazine-2-carboxamide) is an important selective antiviral against RNA-based viruses, like SARS‐CoV‐2 virus causing COVID-19 disease, and has recently attracted considerable interest. The behavior of Favipiravir in various solvents including water, methanol, ethanol, isopropanol, methyl tert-butyl ether (MTBE), and dimethyl sulfoxide (DMSO) was investigated. A novel iron (III) complex compound derived from FAV as the ligand was synthesized. Subsequently, the newly synthesized complex was subjected to various analytical and spectroscopic techniques, including UV and infrared spectroscopy, mass spectrometry, stoichiometry analysis using the molar ratio method, and thermogravimetric analysis (TG–DTA). It was observed that the keto/enolic equilibrium of favipiravir is influenced by the choice of diluent, with the enol tautomer being the predominant form. Further analysis revealed that the isolated metal complex exhibits a tetrahedral geometry. The complexation reaction is more favorable in a protic medium than in an aprotic one, primarily due to the easier deprotonation in protic environments. Additionally, the molecular structures of the free ligand and its metal complex compound were optimized using density functional theory (DFT) simulations. This study offers valuable insights into the quantum chemical properties related to the structure. The simulation indicates significant chemical stability and a pronounced electrophilic character of the iron complex. Overall, these findings contribute to a deeper understanding of the interaction dynamics and stability of favipiravir's metal complexes.

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Turmeric, specifically its curcuminoids such as curcumin (C₂₁H₂₀O₆), possesses extensive therapeutic benefits including anti-inflammatory, anticancer, and anti-aging properties. However, curcumin’s clinical effectiveness is significantly limited by its hydrophobic nature, leading to poor bioavailability. This study aims to enhance the solubility and bioavailability of curcumin through the development of liquisolid compact dispersion formulations. To address curcumin’s limited water solubility (3.12 mg/l at 25 °C) and high oil–water partition coefficient ((text{log}Kow=3.29)), we employed a central composite design (CCD) to optimize liquisolid compact dispersion formulations. The optimization focused on the tablet’s physical properties, such as hardness, disintegration time, and dissolution rate at 30 min. Critical formulation components included Tween 80 as the liquid vehicle and Aerosil 200 as the coating material, serving as independent variables in the optimization process. The optimized formulation, containing 30 mg of Tween 80 and 75 mg of Aerosil 200, significantly improved curcumin’s dissolution rate. Experimental results confirmed the formulation’s effectiveness, with a marked reduction in the time to dissolve 63.2% of the drug to 165 min, compared to 300 min for conventional formulations. Differential scanning calorimetry and Fourier-transform infrared spectra indicated a transformation of curcumin into a non-crystalline state and the formation of hydrogen bonds with Tween 80, contributing to enhanced solubility. This study successfully demonstrates a viable strategy to enhance the bioavailability of curcumin through liquisolid compact dispersion formulations. By addressing the solubility challenges of curcumin, this technique presents a significant advancement in improving the clinical applicability of BCS class II and IV drugs, potentially benefiting a wide range of therapeutic applications.

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Graphical representation of optimizing curcumin liquisolid formulationusing central composite design (CCD) methodology

This study presents a comprehensive evaluation of flare gas recovery technologies at the GL1Z LNG plant (SONATRACH Industry-Algeria), focusing on electricity generation, LPG production, and Gas-to-Liquid (GTL) conversion. Using real-world data and simulations conducted with Aspen HYSYS v12 based on steady-state conditions, we assessed the technical feasibility and economic viability of each method. Our findings reveal that electricity generation is economically viable but offers limited CO₂ reduction benefits. LPG production provides a balanced economic solution. GTL conversion, despite higher initial costs, significantly enhances economic returns and reduces flaring by converting flare gas into high-value liquid hydrocarbons. This study introduces a simulation model, substantiated by the recent literature providing a robust framework for optimizing flare gas recovery. This study highlights the importance of evaluating and comparing tailored solutions to achieve sustainable and efficient flare gas utilization, offering valuable insights for future industrial applications.

Ni(II) {(2a5p)₂[Ni(OH₂)₆][Ni(dipic)₂]₂.2H₂O, 1} and Cu(II) {[Cu(dipic)(2a5p)(H₂O)].H₂O, 2} complexes obtained from 2-amino-5-picoline (2a5p) with dipicolinic acid (H₂dipic) and Cu(II) complex {[(H₂O)(dipic)Cu(OH)Cu(OH)(H₂O)₂Cu(dipic)(H₂O)].2H₂O, 3} of H₂dipic have been synthesized and characterized by atomic absorption spectroscopy (AAS), ultraviolet–visible region (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), conductivity measurement, magnetic measurement and X-ray crystallography. Furthermore, antimicrobial properties of starting and syntheses complexes have also been tested against C. krusei (ATCC 6258), C. albicans (ATCC 14053) and C. parapsilosis (ATCC 22019) (yeast) for antifungal activity and E. faecalis (ATCC 29212), E. coli (ATCC 25922) and S. aureus (ATCC 29213) for antibacterial activity. The antimicrobial activities of results were compared to those of standard agents such as fluconazole, levofloxacin, cefepime and vancomycin.

Biomass has a wide range of uses due to its cost-effectiveness and enormous diversity of functional groups. This research investigates the production of an inexpensive and efficient adsorbent using the stem waste charcoal (FTCC) of Tinospora cordifolia and its use in water decontamination, with a focus on the elimination of metal ions and dyes. The study shows that chemically functionalizing the surface of charcoal with APTES (3-Aminopropyltriethoxysilane) improves adsorption capabilities. Various characterization techniques, such as FTIR, FESEM, TGA, and BET studies, were used to evaluate the efficiency of FTCC. The results showed a considerable improvement in surface qualities that are favourable for adsorption. BET evaluations indicate that functionalized carbon has a high surface area of 1.45766 m².g⁻¹ and a pore volume of 0.534772 cm³.g⁻¹. Adsorption data fit well with Langmuir model and follow pseudo-second-order kinetics. Thermodynamic parameters reveal the endothermic adsorption of Congo red dye and exothermic adsorption of Cr (VI) metal ion. The batch adsorption experiments revealed that FTCC was capable of removing various dyes and metal ions from aqueous solution, with adsorption capacity 65.22 mg/g for Congo red and 56.61 mg/g for Cr (VI). The FTCC showed good reusability potential up to 6th cycle. Additionally, tests with water samples containing contaminants have been conducted to demonstrate the best adsorbent quality of FTCC. The study highlights the feasibility of using functionalized charcoal FTCC derived from agricultural debris as a renewable alternative for restoring the environment and water remediation.

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Argania spinosa is a well-known evergreen tree in Morocco and worldwide due to its significant ecological value, economic potential, and therapeutic uses. In this study, native and introduced Argan trees from two locations in Morocco (Oujda and Chouihiya) were compared for their chemical composition and in vitro antimicrobial activity. The sensitivity of different bacterial and fungal strains to Argan extracts was tested using the agar diffusion, agar well, and microdilution methods. The findings of the present study indicate that each extract from the different studied parts of the Argan tree contained a distinct amount of several compounds of considerable interest, including rutin, catechin, quercetin, and cinnamic acid, the major compound was Quercetin with a value of 18.12 mg/100g DW while the minor was trans Chalcon with a concentration of 0.01 mg/100G DW. The lowest MIC values and MBC value against bacterial strains were recorded by leaf extracts from Oujda against K. pneumoniae with a value of 2.5 mg/mL. The lowest MIC observed for fungal strains was registered against Geotrichum sp with a value of 5 mg/ml. The outcomes from this work further support that Argan and its derivatives have a promising future in combating microbial problems.