Diethyl Ether Research Articles

Bioanalysis of Endogenous Isotretinoin in Altered and Unaltered Human Plasma by Liquid Chromatography-Tandem Mass Spectrometry Coupled with Electrospray Ionization.

Bioanalytical method development and validation of endogenous Isotretinoin with Isotretinoin D5 as internal standard was done as per current regulatory guidelines. The method is simple, rugged and sensitive enough to estimate endogenous Isotretinoin using the chromatography-tandem mass spectrometry technique. An alternative approach has been adopted for quantitative analysis of endogenous Isotretinoin in human plasma. Isotretinoin free matrix (surrogate matrix) was prepared and further used for the development and validation of Isotretinoin. The method was validated in altered and unaltered plasma. The chromatographic optimization was done with column (ACE C18, 100 × 4.6mm I.D. 5μm particle size), using a mobile phase containing 1mM ammonium acetate, pH3.0 as a solvent A and solvent B (1mM ammonium acetate (pH3.0) with acetonitrile in a ratio of 10:90). A flow rate was set at 0.75mL/min in a binary gradient mode. The analyte was recovered by liquid-liquid extraction method with diethyl ether as an extraction solvent. Multi-reaction monitoring mode in negative polarity was implemented for the quantification of endogenous Isotretinoin in plasma. The calibration curve of Isotretinoin was linear (r2 > 0.9992) over the concentration range of 0.5-1000ng/mL. The intra-day precision was found in a range of 2.0-3.9% CV for altered samples and 0.9-3.7% CV for unaltered samples. The inter-day precision was found 2.6-6.1% CV for altered samples and 1.3-3.8% CV for unaltered samples. The average recovery of the extraction procedure was found 64.6% for altered samples and 62.2% for unaltered samples.

Determination of total protein and lipid contents in some soybean varieties

Soybean seeds consist of a lot of necessary nutrients for health, they are considered a complete source of protein andvegetable lipids for the human body. In this study, six soybean varieties (DT22, Coc Chum B, black soybean, Kwangan, Cuc Ha Bac and DT84) were evaluated for total protein, lipids contents and acid and iodine indexes. Total protein content was determined by the Kjeldahl method. Oil was extracted from mature seeds using the Soxhlet system with diethyl ether solvent. The results showed that levels of total protein and lipids are relatively high in tested soybean varieties. The total protein content ranged from 29.36 to 37.32%, and lipids ranged from 19.8 to 21.2%. The free acid index was from 0.12 to 1.69 mg KOH/g, the iodine value was about 52.43 to 68.64 g I2/100 g. Varieties with high protein content were black soybean and Cuc Ha Bac. Nutritionally, these varieties are all sources of high nutritional value in providing protein and essential fatty acids for humans.

Phytochemical analysis of chloroform extract of leaves of Skimmia laureola

The air-dried and powdered leaves (3 kg) of Skimmia laureola were exhaustively defatted with light petroleum ether (60-800). The petroleum free mass extracted with 90% ethanol. The ethanol extract was concentrated under reduced pressure and a suspension of the residue was made with water, which was washed with diethyl ether for several times and then partitioned with CHCl3:H2O:MeOH (6:4:4) in a separatory funnel. The chloroform layer was separated out and concentrated under reduced pressure to give CHCl3 extract (15g). The chloroform extract (10g) was subjected to repeated CC over Si-gel eluted with different proportions of n-hexane- CHCl3 and CHCl3:MeOH afforded β-stosterol (1), (E)-3’-(4-Hydroxyphenyl)-2’-propenoic methyl ester (2), (E)-3’-(4-Hydroxy-3-methoxyphenyl)-2’-propenoic methyl ester (3), Identified as bergapten (4), Identification of these compounds were made by the analysis of their chemical and spectral data.

Arylene Diimide Derivatives as Anolyte Materials with Two-Electron Storage for Ultrastable Neutral Aqueous Organic Redox Flow Batteries

Arylene Diimide Derivatives as Anolyte Materials with Two-Electron Storage for Ultrastable Neutral Aqueous Organic Redox Flow Batteries

Production and characterisation of self-blowing lignin-based foams

Self-blowing lignin-furanic foams were produced using formulations comprising Kraft lignin and furfuryl alcohol as the major components. Diethyl ether, Tween 85 and sulphuric acid were used as blowing agent, surfactant and catalyst. The influence of the components and the ratio of furfuryl alcohol to lignin was investigated with regard to the foam density, mechanical properties, water absorption, thermal properties, and fire behaviour. Depending on the formulation, the density of lignin-furanic foams ranged between 60 and 320 kg m−3. Increasing the furfuryl alcohol content increased the density of the foams. Low-density foams were obtained with a higher proportion of diethyl ether. The compression strength and modulus of elasticity (MoE) of lignin-furanic foams also increased with foam density. All lignin-furanic foams showed good thermal stability and residual masses by thermogravimetric analysis. Cone calorimetric analysis showed that lignin-furanic foams have poor flammability and self-extinguish within few seconds.

COMPOSITION OF LIPOPHILIC COMPONENTS OF RHODODENDRON ADAMSAY ETHER EXTRACT AND AC-TIVITY AGAINST SARS-COV-2 MAIN PROTEASE

The composition of the lipophilic components of the Adams rhododendron RhododendronadamsiiRehd. Acid and neutral components were identified using gas-liquid chromatography with mass spectrometric detection. Methyl tert-butyl ether (MTBE), which has all the advantages of diethyl ether, but is devoid of its disadvantages, was used as the raw material extractant. It does not form peroxides and does not create increased gas contamination due to its higher boiling point. As a result, comparison with databases identified triterpene, phenolcarboxylic and aliphatic acids with a chain length of 8 to 30 carbon atoms, including saturated, unsaturated and dibasic acids. More than 150 triterpene and aliphatic components of the unsaponifiable residue and acid fractions have been identified. Previously, unsaponifiable residues of lipophilic extracts were practically not studied. Only components of Rh.adamsiiand other species of the genus rhododendron essential oils have been studied in detail. For bioactivity testing, samples of the whole extract and its fractionation products were prepared. Some of the studied samples show inhibitory activity against the main protease of SARS-CoV-2.

Study of PCCI engine operating on pine oil diesel blend (P50) with benzyl alcohol and diethyl ether

This article examines the effect of premixing of benzyl alcohol and Diethyl Ether (DEE) in a CI engine fuelled with pine oil diesel fuel blend. The fuel sample is prepared by blending 50% of pine oil with 50% of diesel fuel (P50) on volume basics. The benzyl alcohol and diethyl ether were injected in the premixing ratio of 10% and 20% on the CI engine fuelled with P50. The experimental analysis was conducted in a 4-stroke single cylinder CI engine with added provision to operate on PCCI mode. The engine was operated with constant speed and tested at different torque condition ranging from 0 to 100 % in the interval of 25%. The experiment results shows that premixing of benzyl alcohol and diethyl ether enhanced the brake thermal efficiency by 4.5 % and 8.75 % than P50 respectively and brake specific energy consumptions was low when compared to neat P50 operation. Premixing of diethyl ether and benzyl alcohol increased the emission of CO and HC whereas reduced smoke and NOx emission. There was increase in peak combustion pressure and heat release rate with the premixing of benzyl alcohol however, premixing of diethyl ether resulted in reverse trend.

Concentrated Platinum‐Gallium Nanoalloy for Hydrogen Production from the Catalytic Steam Reforming of Ethanol

AbstractThe steam reforming of ethanol (SRE) is a key process for the production of H2 and other vital hydrocarbons. The present work describes the synthesis of Platinum‐Gallium (Pt−Ga) nanoalloys supported on mesostructured cellular foam (MCF‐17) via ultrasound‐assisted impregnation method. Ga was substituted with Pt in different wt.% i. e. Pt/MCF‐17, Pt99.9Ga0.1/MCF‐17, Pt99Ga1/MCF‐17, and Pt90Ga10/MCF‐17 and was evaluated towards the SRE at a temperature range of 473K‐773 K towards hydrogen (H2), acetaldehyde (CH3CHO), diethylether (DEE), ethylene (C2H4), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and ethane (C2H6). The SRE activity and H2 formation rate with Pt90Ga10/MCF‐17 catalyst were observed to be 68.1 % and 3047.2 nmole g−1 sec−1, which is 9.8 and 4.5 times more than the Pt/MCF‐17 counterparts. Moreover, as observed from DRIFTS, NH3‐TPD and XPS studies Ga showed high interaction with Pt in the electron deficit state which resulted in the increased dehydrogenating and acidic properties that resulted in a higher yield of H2.

Effects of aluminum powder additives on deflagration and detonation performance of JP-10/DEE mixed fuel under weak and strong ignition conditions

As a high-density hydrocarbon fuel with good comprehensive properties, JP-10 is widely used in scramjets and detonation engines. Previous work has improved the ignition susceptibility and reduced incomplete combustion product concentration of JP-10 liquid fuel by blending diethyl ether (DEE). However, the density and bulk calorific value of hydrocarbons do not increase indefinitely with the increase of the ring structure, and the low temperature properties of the fuel gradually deteriorate with the increase of density. Therefore, adding metal dust with higher combustion calorific value to improve the energy density of mixed fuel is a new solution. In the present work, the deflagration and detonation properties of multiphase mixed fuels obtained by adding three aluminum powders with different morphologies and particle sizes (flake aluminum powder, small spherical aluminum powder, large spherical aluminum powder) to the JP-10/DEE mixed fuel were investigated. Under weak ignition conditions, the addition of aluminum powder increases the average burning rate of the multiphase mixed fuel and flame intensity significantly. The increase rate of the flame intensity when spherical powders are added is lower than that of the flake aluminum powder. The addition of aluminum powder is conducive to the early acceleration of deflagration, and the flame intensity reaches a high level earlier. Although the aluminum powder increases the energy of the reaction system, it also aggravates the incomplete combustion of JP-10/DEE in the oxygen-depleted state, and generates a large amount of soot. Under the strong ignition conditions, the DDT process of JP-10/DEE/aluminum powder can be divided into four stages: the slow propagation stage, shock wave formation stage as a result of compression wave superposition, coupling evolution stage of shock wave and flame front, and the detonation stage, respectively corresponding to four different pressure wave pattern. The strong ignition method greatly accelerates the evaporation of JP-10/DEE and the melting of the aluminum core in the initial stage, so that the multiphase mixture quickly changes from a slow propagation mode to a strong deflagration mode.

Experimental Studies on Thermal-Barrier-Coated Engine Fuelled by a Blend of Eucalyptus Oil And DEE.

The present experiment deals with the study of the effect of addition of diethyl ether (DEE) on the performance and emission characteristics of a thermal-barrier-coated (TBC) engine run on papaw (Carica papaya) and eucalyptus oil blends. The fuels studied were test blends, CPME30Eu70 (papaw methyl ester 30% and eucalyptus oil 70%) and CPME30Eu70 + 10% DEE, and diesel. Optimum results were obtained for CPME30Eu70 with DEE in a TBC engine. The addition of DEE creates a lean mixture, and its low viscosity, high cetane number, and volatility improve the performance of biofuel-powered engines. The investigation shows that the addition of 10% DEE gives the best results in brake-specific energy consumption (BSEC), brake-specific fuel consumption (BSFC), and brake thermal efficiency (BTE). The BTE of the DEE-adapted CPME30Eu70 blend was 32.2%, whereas for diesel it was 31.8%, which was 1.2% higher than that of CPME30Eu70 at normal mode of operation. The addition of DEE to CPME30Eu70 reduced BSEC and BSFC by 8.9 and 7.2%, respectively, compared to a non-coated engine powered by CPME30Eu70. The combination of DEE and CPME30Eu70 nominally decreased nitrogen oxide emissions. The carbon monoxide and hydrocarbon emissions of CPME30Eu70 after DEE addition were 0.195% vol. and 38 ppm, respectively, which were 13.3 and 5.1% lower than those for CPME30Eu70 powered by a compression ignition engine. The experiment found that adding DEE to CPME30Eu70 could improve its atomization and spray characteristics. Moreover, the performance and emission characteristics of the CPME30Eu70-powered engine were enhanced.

Selectivity of Ethanol Conversion on Al/Zr/Ce Mixed Oxides: Dehydration and Dehydrogenation Pathways Based on Surface Acidity Properties

AbstractZirconia‐alumina mixed oxides (Zr+Ce)O2−Al2O3 with various mol. ratios (5, 10, 20, 50, and 75 % alumina) were prepared using the sol‐gel method. The catalysts were characterised via XRD, SEM, DTA/TG, BET, and FT‐IR spectroscopy. The acidities of the catalysts were measured through the absorption of anthraquinone and pyridine probe molecules using EPR and IR spectroscopy, respectively. Catalytic activity and selectivity were investigated for ethanol conversion to acetaldehyde, ethylene, and diethyl ether, which were used as model reactions to identify surface‐active sites. The relationship between the surface structure and the dehydration/dehydrogenation activity was evaluated. Diethyl ether formation is promoted by the presence of the ZrO2 tetragonal phase at a low ZrO2/Al2O3 ratio in the sample composition, at which the Lewis acid site has an aluminum‐oxygen environment. The reaction mechanism was also discussed. In the low‐temperature reaction region, dehydrogenation competes with dehydration; ethylene and acetaldehyde share a common reactive intermediate.

Continuous Essential Oil and Oleoresin Extraction from Star Anise (Illicium verum) by Hydrodistillation and Solvent Extraction

Star anise (Illicium verum) is widely used as a medicinal herb and spice. The extracts, essential oil and oleoresin, can be produced by hydro-distillation and steam distillation, while solvent and supercritical fluid extraction can be used to extract oleoresin. In this work, the star anise is distilled to obtain the oil, subsequently, its residue is extracted by solvent extraction to get the oleoresin. Whole and grounded star anise fruit is distilled by hydro-distillation for 8, 12, 16, 20, and 24 hours, thus the highest yield is obtained at 20 hours from grounded fruit, and the highest trans-anethole content of 68.50% is obtained at 8 hours from grounded fruit. Residue from the whole fruit-distillation process is extracted by Soxhlet extraction with three types of solvent (ethanol, diethyl ether, and n-hexane) for 6 hours. The highest yield was obtained from ethanol extraction with 1.16% yield and the highest content of trans-anethol was obtained from n-hexane fraction. One sample with the highest content of anethole from whole and grounded fruit-distilled oil and oleoresin are picked, and later they are tested to measure their antioxidant capacity by Ferric Reducing Antioxidant Power Assay (FRAP).

Evidence for Oxonium Ions in Ethereal "Hydrogen Chloride".

Although solutions of hydrogen chloride in ethereal solvents like diethyl ether or dioxane are commonly employed in the laboratory, the solution structure of these reagents has yet to be firmly established. Here, we analyze solutions of ethereal hydrogen chloride or deuterium chloride in toluene, in dichloromethane, or in the absence of a co-solvent by in situ infrared spectroscopy. The resulting spectra are inconsistent with free HCl or often-proposed 1:1 HCl-ether complexes but closely match the predicted spectra of oxonium ions generated via protonation of diethyl ether. Molecular dynamics simulation of the oxonium chloride complexes provides evidence for an outer-sphere contact ion pair. These results suggest new approaches for tuning the acidity of strong Brønsted acids in organic solvents and demonstrate the importance of conducting spectroscopic measurements under reaction-relevant conditions.

Validation of a radioimmunoassay method for cortisol in buffalo milk whey. A preparatory step for future sensor technology

One animal-based method to evaluate welfare is the presence of stress. In dairy ruminants, the responses to stressors include the activation of both neuroendocrine and autonomous nervous system that can be evaluated through an endocrine assessment. The present study aimed to validate a radioimmunoassay method for cortisol in buffalo milk. Three formulations (whole and skimmed milk and whey) and three solvents (methanol diethyl ether and dichloromethane) were tested: methanol was characterised by the best extraction efficiency (69.88%), whey cortisol concentrations showed a significant correlation with whole extracted milk and were not affected by fat content variation during the milking session. The RIA used in the present study showed good precision, sensitivity and specificity: the dilutions test indicated the high reproducibility of the results, overlapping of the dilution curve and standard curve highlighted high specificity and the lack of interfering factors by buffalo whey matrix. It is concluded that the present assay suits the cortisol measurement in buffalo milk and the ranges described could be employed in the calibration of a biosensing technologies directly integrated in milking parlour systems. Highlights Buffalo milk whey revealed to be a matrix of great interest because of its high stability in terms of storage, transportation and processing. RIA method suits the cortisol measurement in buffalo milk Ranges described can be employed in the calibration of biosensors for non-invasive assessment of cortisol

Renewable energy approach towards powering the CI engine with ternary blends of algal biodiesel-diesel-diethyl ether: Bayesian optimized Gaussian process regression for modeling-optimization

The present study investigates the performance and emissions of a small diesel engine powered with ternary blends of algal biodiesel, diesel, and diethyl ether. The findings indicate that the addition of diethyl ether improved the brake thermal efficiency, peak pressure inside cylinder, and net heat release rate. This is because the additives have a greater oxygen value, higher cetane number, and volatility. However, an increase in NOX emissions was observed. Gaussian Process Regression, a modern supervised machine learning approach, was utilized to develop a prognostic model for the engine's performance and exhaust emission. The Bayesian technique for hyperparameter optimization was used to strengthen the predictive model's training process. As model input parameters, engine load, fuel mixing ratio, and fuel injection pressure were used. The response variables were brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), NOx, HC, and CO. The created prophetic models predicted engine performance and exhaust emission data with high accuracy, as shown by correlation coefficient values ranging from 0.9746 to 0.9999, low mean squared error up to only 11.023, and low mean absolute error ranging from 0.001 to 2.591. The prognostic model for engine performance and emission developed with Bayesian optimized Gaussian process regression could provide a robust simulation and prognostication efficiency.

Purification and characterisation of phytochemicals extracted from Rhizophora mucronata: Their efficacy against Pseudomonas aeruginosa infection in Catla catla

Abstract The aim of this work is to purify and characterise bioactive molecules from various solvent extracts prepared with the leaves of Rhizophora mucronata, a mangrove plant. In vitro assessment of antibacterial activity of n-hexane, diethyl ether, ethanol, and aqueous extracts (AEs) against Bacillus subtilis (0.4 ± 0.1, 1.1 ± 0.3, 0.9 ± 0.1, and 1.2 ± 0.7 mm), Staphylococcus aureus (1.2 ± 0.1, 2.3 ± 0.5, 3.2 ± 1.2, and 4.4 ± 1.7 mm), Klebsiella pneumoniae (0.5 ± 0.3, 1.7 ± 0.4, 3.9 ± 1.4, and 3.9 ± 0.9 mm), and Pseudomonas aeruginosa (0.2 ± 0.1, 2.5 ± 0.6, 3.7 ± 0.5, and 4.2 ± 1.3 mm) has proven to act as potent similar to that of commercial antibiotic. Corresponding to antibacterial activity result, antioxidant activity was also higher for AE (75.97% ± 0.5%) compared to remaining extracts (73.77% ± 2.5%, 69.99% ± 0.4%, and 65.24% ± 1.8%) at a concentration of 500 μg·mL−1. Considering both the activities, AE was selected for separation of bioactive molecule by deploying two purification techniques – column chromatography and preparative thin layer chromatography consecutively. After purification, the sample was injected into mass spectrometer and the presence of N-p-coumaroyltyramine and luteolin with excellent antibacterial and antioxidant properties (13.1 ± 2.2 mm and 80.9% ± 2.3%, respectively) were recognised. Further, in vivo investigations on Catla catla fingerlings infected with P. aeruginosa indicated that partially purified extracts cured the infection and resulted in a 100% survival rate.

Development and Validation of a New GC-FID Method for the Determination of Short and Medium Chain Free Fatty Acids in Wine.

A new analytical method for the determination of six volatile short and medium-chain fatty acids (acetic, propionic, isobutyric, isovaleric, hexanoic, and octanoic acids) through liquid-liquid extraction with diethyl ether, followed by GC-FID analysis, was developed and validated. The extraction conditions were optimized by evaluating the effect of the number of extractions (1 to 3) and the effect of the addition of salts (NaH2PO4, (NH4)2SO4, NaCl, (NH4)2SO4/NaH2PO4) to increase the concentration of the analytes in the ethyl ether phase. Results showed that a single extraction allows obtaining the highest sensitivity (due to the impossibility of evaporating the solvent to avoid losses of the analytes). The use of salting out agents, in particular, NaH2PO4, showed an important increase in the extraction extent, on average, 1.5 times higher as compared to the extraction performed without salt. The proposed method is rapid, requiring a total of 30 min for preparation and analysis, and it makes use of small amounts of sample (500 µL) and solvent (400 µL). The method was then applied to quantify the analytes in 5 white wines and 5 red wines, allowing to highlight some clear differences between red and white wines, with the red ones having a significantly higher amount of acetic acid (715.7 ± 142.3 mg/L in red wines and 351.5 ± 21.2 mg/L in white wines) and the white wines having a significantly higher amount of hexanoic and octanoic acid (6.1 ± 3.0 mg/L and 2.6 ± 0.8 mg/L, respectively, are the mean concentrations in white wines, and 4.7 ± 0.8 and 2.4 ± 0.4 mg/L, respectively, are the mean concentrations in red wines).

Operating Range, Performance and Emissions of an HCCI Engine Fueled with Fusel Oil/Diethyl Ether: An Experimental Study

The main disadvantages of HCCI engines are the knocking tendency at high engine loads, the challenge of the start of the combustion, control of the combustion phase, and the narrow operating range. In this study, we aimed to control the combustion processes in HCCI engines and to expand their working range by improving the fuel properties of fusel oil by the addition of diethyl ether. Thus, the variations in the in-cylinder pressure, rate of heat release, indicated mean effective pressure, start of combustion, combustion duration, CA50, indicated thermal efficiency, mean pressure rise rate, hydrocarbon and carbon monoxide emissions were investigated. It was observed that the in-cylinder pressure and rate of heat release were taken into advance and the test engine could be operated for a wider range by increasing the diethyl ether ratio in the blend. The indicated mean effective pressure increased by 67.5% with DEE40 fuel compared to the DEE80. Under the same operating conditions, HC and CO emissions decreased by 41.6% and 56.2%, in use of DEE40. Furthermore, the highest indicated thermal efficiency was obtained as 42.5% with DEE60 fuel. Maximum hydrocarbon and carbon monoxide emissions were observed with DEE80 fuel as 0.532% and 549 ppm, respectively.

Synthesis of Oxygenated Hydrocarbons from Ethanol over Sulfided KCoMo-Based Catalysts: Influence of Novel Fiber- and Powder-Activated Carbon Supports

Ethanol has become a viable feedstock for basic organic synthesis. The catalytic conversion of ethanol provides access to such chemicals as diethyl ether, ethyl acetate, and acetaldehyde. Carbonaceous materials are extensively studied as supports for heterogeneous catalysts due to their chemical and thermal stability, high surface area, and tunable texture. In this paper, ethanol conversion over K10Co3.7Mo12S-catalysts supported on novel activated carbon (AC) materials (i.e., novel powder-AC (DAS and YPK-1), fiber non-woven AC material (AHM), and fabric active sorption (TCA)) was investigated. The catalysts were prepared by the incipient wetness co-impregnation method followed by sulfidation. The catalysts were characterized by employing N2 adsorption–desorption measurements, TEM, SEM/EDX, UV–Vis spectroscopy, and XRF. Catalytic performance was assessed in a fixed-bed down-flow reactor operating at 320 °C, 2.5 MPa, and with continuous ethanol feeding in an He atmosphere. Activity is highly dependent on the support type and catalyst’s textural properties. The activity of the fiber-supported catalysts was found to be greater than the powder-supported catalysts. Ethanol conversion at T = 320 °C, P = 2.5 MPa, and GHSV = 760 L h−1 kgcat−1 increased as follows: (38.7%) KCoMoS2/YPK-1 < (49.5%) KCoMoS2/DAS < (58.2%) KCoMoS2/TCA < (67.1%) KCoMoS2/AHM. Catalysts supported by powder-AC enhanced the formation of MoS2-crystallites, whereas the high acidity of fiber-AC seemed to inhibit the formation of MoS2-crystallites. Simultaneously, a high surface area and a microporous catalytic structure enhance the formation of oxygenates from hydrocarbons. The dehydration and dehydrogenation reactions, which led to the creation of ethene and acetaldehyde, were shown to require a highly acidic catalyst, while the synthesis of ethyl acetate and higher alcohols required a less acidic catalyst.

Experimental study of castor biodiesel ternary blends with ethanol, butanol, diethyl ether and dibutyl ether in a diesel engine

Experimental study of castor biodiesel ternary blends with ethanol, butanol, diethyl ether and dibutyl ether in a diesel engine