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Dalton Transactions (Cambridge, England... Jul 2023Natural gas plays an important role in daily life and the petrochemical industry, but there are often large amounts of impurities which prevent the full use of methane...
Natural gas plays an important role in daily life and the petrochemical industry, but there are often large amounts of impurities which prevent the full use of methane in natural gas. Developing excellent adsorbents to purify CH from multi-component mixtures is crucial, but also faces great challenges. Here, by utilizing a ligand conformation preorganization strategy, we employ a flexible nonplanar hexacarboxylate ligand with 2 symmetry to successfully construct a robust microporous metal-organic framework {[Cu(bmipia)(HO)]·(DMF)(CHCN)} (GNU-1, bmipia = 5-[,-bis(5-methylisophthalic acid)amion] isophthalate) with an unprecedented topology. More importantly, the obtained GNU-1 not only exhibits good stability in acid-base and water environments, but also shows potential utility as an adsorbent for efficient separation and purification of natural gas under ambient conditions. The adsorption isotherms of GNU-1a (activated GNU-1) exhibit strong binding affinities for CH and CH, a remarkable uptakes of CH (6.64 mmol g) and CH (4.6 mmol g) and an excellent selectivity of 330.1 and 17.5 for CH/CH and CH/CH mixtures, respectively, at 298 K and 1 bar. The breakthrough experiments demonstrate that the ternary CH/CH/CH mixtures are completely separated using a fixed-bed separator packed with GNU-1a at ambient temperature and also show great potential for recovering the CH and CH contents from natural gas. Finally, Grand Canonical Monte Carlo simulations are adopted to ascertain potential gas adsorption mechanisms. This work proves the feasibility of optimizing the structure and pore size of MOF materials by regulating the conformation of ligands for application in the field of light hydrocarbon adsorption/separation.
PubMed: 37381747
DOI: 10.1039/d3dt00979c -
Dalton Transactions (Cambridge, England... Oct 2023An efficient water-based purification strategy for metal-organic polyhedra (MOPs) using commercially available centrifugal ultrafiltration membranes was developed....
An efficient water-based purification strategy for metal-organic polyhedra (MOPs) using commercially available centrifugal ultrafiltration membranes was developed. Having a diameter above 3 nm, MOPs were almost fully retained by the filters, while free ligands and other impurities were washed away. MOP retention also enabled efficient counter-ion exchange. This method paves the way for the application of MOPs with biological systems.
PubMed: 37341496
DOI: 10.1039/d3dt01644g -
Biotechnology Advances 2024Anaerobic digestion (AD) is an effective and applicable technology for treating organic wastes to recover bioenergy, but it is limited by various drawbacks, such as long... (Review)
Review
Anaerobic digestion (AD) is an effective and applicable technology for treating organic wastes to recover bioenergy, but it is limited by various drawbacks, such as long start-up time for establishing a stable process, the toxicity of accumulated volatile fatty acids and ammonia nitrogen to methanogens resulting in extremely low biogas productivities, and a large amount of impurities in biogas for upgrading thereafter with high cost. Microbial electrolysis cell (MEC) is a device developed for electrosynthesis from organic wastes by electroactive microorganisms, but MEC alone is not practical for production at large scales. When AD is integrated with MEC, not only can biogas production be enhanced substantially, but also upgrading of the biogas product performed in situ. In this critical review, the state-of-the-art progress in developing AD-MEC systems is commented, and fundamentals underlying methanogenesis and bioelectrochemical reactions, technological innovations with electrode materials and configurations, designs and applications of AD-MEC systems, and strategies for their enhancement, such as driving the MEC device by electricity that is generated by burning the biogas to improve their energy efficiencies, are specifically addressed. Moreover, perspectives and challenges for the scale up of AD-MEC systems are highlighted for in-depth studies in the future to further improve their performance.
Topics: Biofuels; Electrolysis; Anaerobiosis; Bioelectric Energy Sources; Bioreactors; Methane
PubMed: 38714276
DOI: 10.1016/j.biotechadv.2024.108372 -
Heliyon Oct 2023Phosphate oxygen isotope (δO) technique is an effective tool to identify the source and transformation process of phosphorus. The poor applicability of existing δO...
Phosphate oxygen isotope (δO) technique is an effective tool to identify the source and transformation process of phosphorus. The poor applicability of existing δO pretreatment methods for sediments hindered the large-scale application of δO technology. This paper presents an optimization framework for the pretreatment of sediment δO samples based on large-scale applications, using the Fuyang River Basin as a case study. The typical channel landscape outflow lake, South Lake, was selected as the most favorable point for assessing the applicability and optimizing the mainstream δO pretreatment method, which was achieved by clarifying the sediment environmental characteristics of South Lake. To evaluate the suitability of the Blake and McLaughlin methods in South Lake, a comparative study was carried out based on five dimensions: phosphorus recovery rate, removal efficiency of organic matter, removal efficiency of extraction liquid impurity ion, experimental time, and reagent consumption cost. The findings demonstrated that the Blake method outperformed the McLaughlin method across all five dimensions. Based on the environmental characteristics of the sediments of South Lake, the Blake method was optimized from two perspectives, namely the substitution of reagents and adjustment and optimization of experimental procedures. This resulted in an enhancement of phosphorus recovery and organic matter removal efficiency, while also reducing the experimental time required. The optimized method also yielded satisfactory results when applied to the entire watershed. This research paper can thus offer valuable technical support for the widespread application of sediment δO technology.
PubMed: 37817992
DOI: 10.1016/j.heliyon.2023.e20607 -
Journal of Food Science and Technology Oct 2023Sesame oil (SO), one of the most popular and expensive edible oils, is prone to adulteration. In this study, the fatty acid profiles of pure sesame seed oil and samples...
Sesame oil (SO), one of the most popular and expensive edible oils, is prone to adulteration. In this study, the fatty acid profiles of pure sesame seed oil and samples adulterated with two less expensive edible oils (canola and sunflower) were analyzed using Gas Chromatography. A dedicated e-nose system was developed and tested on 15 mixtures of sesame-canola and sesame-sunflower samples. Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), and Multi-Layered Perceptron (MLP) methods were utilized to identify adulteration through the evaluation of Volatile Organic Compound. Result of chromatography showed that most samples of sesame oil containing impurities at levels less than 30% were recognized incorrectly in the standard range of SO fatty acids. This is while the developed e-nose system was able to detect adulteration at much lower levels. According to the results, PCA and LDA methods can describe the data set variance with precision of 95.6% and 97%, respectively. The MLP model had better results compared to PCA and LDA, with high determination coefficient (R = 0.981) and low RMSE (0.0178). Results indicate that the e-nose system provided an effective non-destructive method to detect SO adulteration at levels as low as 5%, which GC was unable to detect.
PubMed: 37599854
DOI: 10.1007/s13197-023-05792-2 -
International Journal of Molecular... Feb 2024A reversed-phase high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of the potential impurities of dexketoprofen,...
Simultaneous Determination of Enantiomeric Purity and Organic Impurities of Dexketoprofen Using Reversed-Phase Liquid Chromatography-Enhancing Enantioselectivity through Hysteretic Behavior and Temperature-Dependent Enantiomer Elution Order Reversal on Polysaccharide Chiral Stationary Phases.
A reversed-phase high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of the potential impurities of dexketoprofen, including the distomer R-ketoprofen. After screening the separation capability of four polysaccharide columns (Lux Amylose-1, Lux Amylose-2, Lux Cellulose-1 and Lux Cellulose-2) in polar organic and in reversed-phase modes, appropriate enantioseparation was observed only on the Lux Amylose-2 column in an acidified acetonitrile/water mixture. A detailed investigation of the mobile phase composition and temperature for enantio- and chemoselectivity showed many unexpected observations. It was observed that both the resolution and the enantiomer elution order can be fine-tuned by varying the temperature and mobile phase composition. Moreover, hysteresis of the retention times and enantioselectivity was also observed in reversed-phase mode using methanol/water mixtures on amylose-type columns. This could indicate that the three-dimensional structure of the amylose column can change by transitioning from a polar organic to a reversed-phase mode, which affects the enantioseparation process. Temperature-dependent enantiomer elution order and rare enthalpic/entropic controlled enantioseparation in the operative temperature range were also observed in reversed-phase mode. To find the best methodological conditions for the determination of dexketoprofen impurities, a full factorial optimization design was performed. Using the optimized parameters (Lux Amylose-2 column with water/acetonitrile/acetic acid 50/50/0.1 (//) at a 1 mL/min flow rate at 20 °C), baseline separations were achieved between all compounds within 15 min. Our newly developed HPLC method was validated according to the current guidelines, and its application was tested on commercially available pharmaceutical formulations. According to the authors' knowledge, this is the first study to report hysteretic behavior on polysaccharide columns in reversed-phase mode.
Topics: Amylose; Chromatography, Reverse-Phase; Temperature; Polysaccharides; Cellulose; Chromatography, High Pressure Liquid; Water; Acetonitriles; Stereoisomerism; Ketoprofen; Tromethamine
PubMed: 38473945
DOI: 10.3390/ijms25052697 -
Se Pu = Chinese Journal of... Dec 2023The addition of -agonists to animal feed can significantly improve the lean-meat rate of pigs, cattle, sheep, and other animals. However, the food residues of -agonists...
The addition of -agonists to animal feed can significantly improve the lean-meat rate of pigs, cattle, sheep, and other animals. However, the food residues of -agonists are harmful to human health. When meat with -agonist residues is consumed, poisoning symptoms such as palpitation, dizziness, and muscle tremors may develop, and damage to the cardiovascular system, liver, and kidney may occur. In this study, a method based on ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was established for the rapid detection of 14 -agonists (clenbuterol, salbutamol, ractopamine, clorprenaline, terbutaline, tulobuterol, bromobuterol, bambuterol, zilpaterol, mabuterol, fenoterol, arformoterol, cimaterol, and cimbuterol) in animal food sources. The sample pretreatment method and chromatographic conditions were optimized. The samples were hydrolyzed with -glucuronidase hydrochloride/aryl sulfate esterase in ammonium acetate buffer (pH 5.2). Enzymatic hydrolysis was performed in a constant-temperature water bath ((36±2) ℃) oscillator for 16 h. The samples were cooled to room temperature and extracted with 0.5% formic acid acetonitrile. NaCl was added to separate the organic and aqueous phases, and 5 mL of the upper organic layer was purified using a one-step purification solid-phase extraction column. After drying with nitrogen at 50 ℃, the residue was dissolved in 0.4 mL of 0.2% formic acid aqueous solution. The samples were passed through a 0.22 μm filter and detected by UHPLC-MS/MS with gradient elution using acetonitrile and 0.1% formic acid aqueous solution as the mobile phases. The analytes were separated on a Phenomenex Kinetex F5 column and detected by positive-ion scanning in multiple-reaction monitoring (MRM) mode. Internal and external standard methods were used for quantitative analysis. The effects of the extract pH, solid-phase extraction column, purification method, and dissolved solution on the extraction efficiency were optimized during pretreatment. UHPLC-quadrupole time-of-flight MS was used to verify the purification effect of the one-step purification solid-phase extraction column, and the results indicated that this type of column could remove most of the phospholipids, sphingolipids, and glycerides in the sample extract. The factors influencing the different chromatographic columns and mobile phases were investigated. MS scanning was conducted in positive-ion mode with needle pump injection in mass-only mode, and the two daughter ions with the highest responses for each target were selected as the quantitative and qualitative ions. The declustering potential (DP) and collision energy (CE) of each ion were separately optimized in MRM mode. The switching mode of the mass spectrum and waste liquid was used, and the mobile phase was switched to waste liquid after all the target peaks were removed. These steps ensured that impurities in the sample flowed out of the column in a timely manner and that the effects of excessive impurities on the mass spectra were avoided. The 14 -agonists showed good linear relationships in the range of 1.0-50 μg/L, with correlation coefficients of >0.99. The limits of detection (LODs) and quantification (LOQs) were in the range of 0.1-0.2 and 0.3-0.6 μg/kg, respectively. The average recoveries of the 14 -agonists ranged from 70.25% to 117.48%, with relative standard deviations (RSDs) in the range of 0.63%-14.29% at low, medium, and high spiked levels. Pork, beef, and mutton samples were selected and analyzed using the developed method. The results were close to those of the national standard method, indicating that the method is accurate and reliable. Moreover, the proposed method has good stability and high accuracy; thus, it is suitable for the qualitative and quantitative determination of -agonists in animal meat.
Topics: Humans; Animals; Swine; Cattle; Sheep; Chromatography, High Pressure Liquid; Tandem Mass Spectrometry; Meat; Acetonitriles; Ions; Solid Phase Extraction
PubMed: 38093540
DOI: 10.3724/SP.J.1123.2023.03008 -
Small Methods Aug 2023MXenes are an emerging class of 2D materials with unique properties including metallic conductivity, mechanical flexibility, and surface tunability, which ensure their...
MXenes are an emerging class of 2D materials with unique properties including metallic conductivity, mechanical flexibility, and surface tunability, which ensure their utility for diverse applications. However, the synthesis of MXenes with high crystallinity and atomic stoichiometry in a low-cost process is still challenging because of the difficulty in controlling the oxygen substitute in the precursors and final products of MXenes, which limits their academic understanding and practical applications. Here, a novel cost-effective method is reported to synthesize a highly crystalline and stoichiometric Ti C T MXene with minimum substitutional oxygen impurities by controlling the amount of excess carbon and time of high-energy milling in carbothermal reduction of recycled TiO source. The highest used content (2 wt%) of excess-carbon yields TiC with the highest carbon content and minimal oxygen substitutes, which leads to the Ti AlC MAX phase with improved crystallinity and atomic stoichiometry, and finally Ti C T MXene with the highest electrical conductivity (11738 S cm ) and superior electromagnetic shielding effectiveness. Additionally, the effects of carbon content and substitutional oxygen on the physical properties of TiC and Ti AlC are elucidated by density-functional-theory calculations. This inexpensive TiO -based method of synthesizing high-quality Ti C T MXene can facilitate large-scale production and thus accelerate global research on MXenes.
PubMed: 36855195
DOI: 10.1002/smtd.202201715 -
Archives of Microbiology May 2024In many European regions, both local metallic and non-metallic raw materials are poorly exploited due to their low quality and the lack of technologies to increase their...
In many European regions, both local metallic and non-metallic raw materials are poorly exploited due to their low quality and the lack of technologies to increase their economic value. In this context, the development of low cost and eco-friendly approaches, such as bioleaching of metal impurities, is crucial. The acidophilic strain Acidiphilium sp. SJH reduces Fe(III) to Fe(II) by coupling the oxidation of an organic substrate to the reduction of Fe(III) and can therefore be applied in the bioleaching of iron impurities from non-metallic raw materials. In this work, the physiology of Acidiphilium sp. SJH and the reduction of iron impurities from quartz sand and its derivatives have been studied during growth on media supplemented with various carbon sources and under different oxygenation conditions, highlighting that cell physiology and iron reduction are tightly coupled. Although the organism is known to be aerobic, maximum bioleaching performance was obtained by cultures cultivated until the exponential phase of growth under oxygen limitation. Among carbon sources, glucose has been shown to support faster biomass growth, while galactose allowed highest bioleaching. Moreover, Acidiphilium sp. SJH cells can synthesise and accumulate Poly-β-hydroxybutyrate (PHB) during the process, a polymer with relevant application in biotechnology. In summary, this work gives an insight into the physiology of Acidiphilium sp. SJH, able to use different carbon sources and to synthesise a technologically relevant polymer (PHB), while removing metals from sand without the need to introduce modifications in the process set up.
Topics: Iron; Acidiphilium; Oxidation-Reduction; Hydroxybutyrates; Polyesters; Polymers; Culture Media; Biomass; Polyhydroxybutyrates
PubMed: 38775940
DOI: 10.1007/s00203-024-04005-4 -
Materials (Basel, Switzerland) Sep 2023The effect of the channel interface of top-gate InGaZnO (IGZO) thin film transistors (TFTs) on the electrical properties caused by exposure to various wet chemicals such...
The effect of the channel interface of top-gate InGaZnO (IGZO) thin film transistors (TFTs) on the electrical properties caused by exposure to various wet chemicals such as deionized water, photoresist (PR), and strippers during the photolithography process was studied. Contrary to the good electrical characteristics of TFTs including a protective layer (PL) to avoid interface damage by wet chemical processes, TFTs without PL showed a conductive behavior with a negative threshold voltage shift, in which the ratio of Ga and Zn on the IGZO top surface reduced due to exposure to a stripper. In addition, the wet process in photolithography increased oxygen vacancy and oxygen impurity on the IGZO surface. The photo-patterning process increased donor-like defects in IGZO due to organic contamination on the IGZO surface by PR, making the TFT characteristics more conductive. The introduction of ozone (O) annealing after photo-patterning and stripping of IGZO reduced the increased defect states on the surface of IGZO due to the wet process and effectively eliminated organic contamination by PR. In particular, by controlling surface oxygens on top of the IGZO surface excessively generated with O annealing using UV irradiation of 185 and 254 nm, IGZO TFTs with excellent current-voltage characteristics and reliability could be realized comparable to IGZO TFTs containing PL.
PubMed: 37763439
DOI: 10.3390/ma16186161