Mixture Of N-hexane Research Articles

Isolation of Flavonoid Compounds Derived from Buni Leaves (Antidesma bunius (L) Spreng.)

The flavonoid compounds from the leaves of buni (A. bunius (L) Spreng.) have been isolated through a process of maceration utilizing methanol as the solvent. The concentrated methanol extract was combined with ethyl acetate. The concentrated ethyl acetate extract was subsequently dissolved in methanol and subjected to partition extraction using n-hexane. The concentrated methanol extract was acidified with 6% HCl, followed by partition extraction using chloroform. The concentrated chloroform extract was isolated using column chromatography, employing an eluent mixture of n-hexane and ethyl acetate in the following ratios: 90:10, 80:20, 70:30, and 60:40 (v/v). The compounds underwent purification via TLC preparative, resulting in a tawny paste with a mass of 30 mg and an Rf value of 0.31. The compound underwent additional identification through the application of Ultraviolet Visible (UV-Vis) spectroscopy, Fourier Transform-Infrared Spectroscopy (FT-IR), and Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR), leading to the conclusion that the flavonoid in question is isoflavone.

COSMO-RS prediction, experimental investigation, and mechanism analysis: A new approach to separating the n-hexane - tert-butanol azeotropic system via liquid-liquid extraction with ionic liquids

n-Hexane and tert-Butanol (TBA) are frequently utilized to refine the conditions for Grignard, Wittig, and Friedel-Crafts alkylation reactions. During the synthesis of loratadine, the formation of azeotropic mixtures n-hexane and TBA, which are challenging to separate through conventional distillation, is inevitable. This study utilizes the COSMO-RS model to identify suitable ionic liquids (ILs) for the separation of the n-hexane - TBA azeotropic system. Based on solvent capacity and selectivity, 1-ethyl-3-methylimidazolium trifluoroacetate ([EMIM][TFA]), 1-butyl-3-methylimidazolium trifluoroacetate ([BMIM][TFA]), and 1-hexyl-3-methylimidazolium trifluoroacetate ([HMIM][TFA]) were selected as extractants. The liquid–liquid equilibrium (LLE) data for the n-hexane - TBA - ILs ternary system were measured at 303.15 K and atmospheric pressure. Distribution coefficients and selectivity were calculated to evaluate the performance of the extractants, with the NRTL model used to correlate the experimental LLE data. The consistency of the NRTL model parameters was corroborated through topological analysis associated with the Gibbs tangent principle. Quantum chemical calculations, including interaction energy, ESP analysis, IGMH analysis, and QTAIM topological analysis, were performed to explore the separation mechanism at the molecular level. The results indicated that the interaction energies between the ILs and TBA were higher than those between the ILs and n-hexane, indicating a stronger attraction of ILs to TBA. Consequently, the ILs effectively separated TBA from the n-hexane - TBA azeotropic system, with extraction capacities ranked as [EMIM][TFA] > [BMIM][TFA] > [HMIM][TFA]. The quantum chemical calculations successfully explained the experimental results, aligning with COSMO-RS model predictions and confirming their reliability. IGMH and QTAIM topological analyses systematically explored the types and strengths of interactions, revealing that hydrogen bonds are predominant between the ILs and TBA, with additional contributions from van der Waals forces. Furthermore, the hydrogen bond strengths between TBA and the anions and cations of the ILs are classified as strong and moderate, respectively. This work provides valuable insights into the separation of azeotropic systems using ILs, elucidating the underlying mechanisms behind this process.

Method for determination of gamma oryzanol in dietary supplement by high performance liquid chromatography

Gamma oryzanol (GO), a phytosterol found most abundantly in rice bran oil as well as corn, barley, rye, vegetable oils and wheat bran. Thanks to its ability to slow down the development of melanin pigments, prevent the effects and spread of ultraviolet rays on the skin's surface, limiting freckles and darkening of the skin, in recent years, GO has been added to dietary supplements to help reduce melasma, brighten and smooth the skin. For the purpose of evaluating and controlling product quality, the GO analysis method was developed and validated. GO was analyzed by HPLC using a PDA detector with a C18 chromatography column (250 mm × 4.6 mm, 5 µm) and a mobile phase consisting of methanol and acetonitrile in isocratic mode 35: 65 (v/v). The test sample was extracted with a mixture of n-hexane and ethanol at a ratio of 2: 5 (v/v). The method was evaluated for system suitability, specificity, calibration curve, precision and accuracy with limit of detection and limit of quantification were 15.0 µg/g and 50.0 µg/g, respectively. The analysis results of 10 real samples including 03 pellet samples and 07 powder samples showed that the method is suitable for analyzing samples with different concentration ranges.

Development and validation of High-Performance Thin Layer Chromatographic methods for simultaneous determination of antibacterial pharmaceutical formulations containing Clindamycin phosphate.

The main objective of this research is to establish and authenticate the High-Performance Thin-Layer Chromatographic techniques for the simultaneous assessment of Clindamycin phosphate in combination with Tretinoin (formulation-1) and Clindamycin phosphate with Adapalene (formulation-2), both of which are antimicrobial combinations. In the developed HPTLC methods, for combination-1, the optimized mobile phase was a mixture of n-Hexane: Ethyl acetate: ACN: Methanol (5:2:2:1 by volume) with observed Rf values of 0.413 and 0.787 for Clindamycin phosphate and Tretinoin, respectively. Similarly, for combination-2, the mobile phase comprised n-Hexane: Diethyl ether: Dichloromethane: Acetic acid (4:4:2:0.1 by volume) with recorded Rf values of 0.407 and 0.559 for Clindamycin phosphate and Adapalene, respectively. The developed methods are successfully validated as per the regulatory guidelines. This approach proves to be significantly time-saving and costeffective, rendering it suitable for routine analyses of the formulations containing selected antibacterial active pharmaceutical ingredients and commercial formulations.

Changes of structural characteristics, functional properties and volatile compounds of Tenebrio molitor larvae protein after sustainable defatting process: Influence of the different volume ratios of n-hexane to ethanol

This work aimed to study the effect of defatting via the mixture of n-hexane and ethanol under different volume ratio on the changes of structural characteristics, functional properties and volatile compounds of Tenebrio molitor larvae protein (TMLP). The results showed that 1:0.6 vol ratio of n-hexane to ethanol rendered the highest defatting rate (P < 0.05), as well as led to the highest EAA/AA contents, sulfhydryl contents, surface hydrophobicity, solubility, water/oil holding capacities and emulsifying properties of TMLP (P < 0.05). However, higher volume ratio of n-hexane to ethanol led to negative impacts on functionalities of TMLP. Moreover, the contents of aldehydes and hydrocarbons which rendered off-flavour to TMLP significantly decreased with the increasing volume ratio of n-hexane to ethanol (P < 0.05), while the contents of pleasure flavour (hydrocarbons and ester compounds) were obviously enhanced. This study provides an eco-friendly defatting method on the processing of TMLP with superior quality attributes.

Efficient separation of linear and mono-branched hexane isomers using large-area silicalite-1 membranes

Membrane-based hydrocarbon isomer separation is a promising and energy-saving alternative to distillation. For the first time, tubular silicalite-1 membranes with large areas of 180 cm2 were employed in this study to separate linear and mono-branched hexane isomers. The membrane had a thickness of around 8 μm and showed highly (h0h) orientation. In binary and ternary mixtures of n-hexane (n-C6), 2-methylpentane (2MP), and 3-methylpentane (3MP), the effects of temperature and partial pressure on the separation performance of silicalite-1 membrane were examined. Moreover, the long-term stability of the membrane in binary and ternary mixture separation was also investigated. The large-area membrane showed a n-C6 permeance of 2.4 × 10-8 mol/(m2 s Pa) and n-C6/2MP and n-C6/3MP separation factors of 36 and 74 in the ternary n-C6/2MP/3MP (2.8 kPa/2.9 kPa/2.8 kPa) mixture with N2 as the balanced gas at 100 kPa absolute and 303 K, respectively. The scaling-up membranes demonstrated good and stable separation performance during the long-term test, highlighting the effectiveness and potential application of using large-area silicalite-1 membranes for the separation of hexane isomer mixtures.

An Integrated Metabolomics Study on Antidiabetic Activity of Christia vespertilionis Leaves Extract Using Chemometric and Molecular Docking Analysis.

In disease treatment, the utilisation of medicinal plants has witnessed a discernible rise, driven by concerns over the adverse effects associated with synthetic drugs available in the market. Analyses of the plant Christia vespertilionis (L.f.) Bakh. F., indigenous to Malaysia, has suggested its antidiabetic property linked to α-glucosidase inhibition, but metabolites responsible for antidiabetic are unexplored. The metabolomics approaches and molecular docking simulations were integrated to identify the putative α-glucosidase inhibitors and their enzyme interaction. In this study, the crude leaves extracted from this plant were extracted using solvents of varying polarity, followed by gas and liquid chromatography coupled with mass spectrometry metabolomics. The highest inhibition activity in a mixture of n-hexane and ethyl acetate (1:1, v/v)) was observed. Six putative metabolites corresponding to antidiabetic activity were identified: palmitic acid (2), linolenic acid (4), 7-tetradecenal (5), aloeemodin-8-monoglucoside (14), bruceine I (15), and sanjidin B (16). The mechanism of action of all the identified compounds is competitive, mainly involving hydrophobic and hydrogen bonding interactions with the protein residues. Compounds 14, 15, and 16 exhibited strong binding capabilities with both enzyme crystal structures compared to the positive control, quercetin. The metabolites extracted from C. vespertilionis leaves have demonstrated promising antidiabetic effects. These antidiabetic compounds can potentially commercialise new drug candidates in managing diabetes conditions.

Hydrogel Coated Mesh with Controlled Flux for Oil/Water Separation.

Superwetting surfaces are often applied in oil/water separation. Hydrogels have been widely prepared as superhydrophilic/underwater superoleophobic materials for oil/water separation since they are naturally hydrophilic. Hydrogels usually need to be combined with porous substrates such as stainless steel mesh (SSM) due to their poor mechanical properties. However, it is usually inevitable that the pores of the substrate are clogged during the actual preparation process, leading to a significant decrease in the flux, which limits its effective application. In this study, acrylic acid (AA), chitosan (CS) and modified silica were utilized to form a layer of dual-network PAA/CS@SiO2 hydrogel by photopolymerization on SSM, followed by a simple and novel ultrasonic-assisted pore-making method to generate numerous pores in situ on the surface of the hydrogel-coated mesh, which led to an increase in water flux from 0 to 70,000 L m-2 h-1 without decreasing the separation efficiency. After 100 separations of a mixture of n-hexane and water, the flux was still higher than 50,000 L m-2 h-1 with a separation efficiency above 99%, which is superior to most of hydrogel-coated meshes reported so far. Moreover, the prepared PAA/CS@SiO2 hydrogel-coated mesh also has good environmental stability, low swelling, and self-cleaning properties. We believe that the strategy of this study will provide a simple new perspective when hydrogels block the substrate pores, resulting in low water flux.

Thin layer chromatography of methylated derivatives of sodium alkylbenzenesulfonates in water analysis by GC-MS

Sodium alkylbenzene sulfonates or linear alkyl benzene sulfonates (LAS) are the most common synthetic anionic surfactants and water pollutants. They can cause both acute and chronic toxic effects on water organisms. Selective determination of sodium alkylbenzene sulfonates as a separate class of anionic surfactants is possible using gas chromatography coupled with mass spectrometry (GC-MS) in the form of linear alkylbenzenesulfonic acid methyl esters (LABSA ME). In order to purify the extracts and concentrate the analytes, we studied the behaviour of these compounds by ascending high-performance thin-layer chromatography using Kieselgel 60 F254 and Sorbfil plates. A mixture of n-hexane and methanol solvents in a ratio of 23:1 (by volume) was used as the mobile phase. Under these conditions, sodium alkylbenzenesulphonates remain on the start line, while their derivatives (ME ABSC), obtained by methylation with trimethyl orthoformate in the presence of trifluoroacetic acid (with a yield of η=98%), form zones characterised by retention coefficient values of Rf = 0.62 and Rf = 0.71 on Kieselgel 60 F254 and Sorbfil plates, respectively. The repeatability of the Rf values was characterised by a standard deviation of 6.1 and 5.9 %, respectively (n=16). The completeness of extraction (95.0–100.0 %) of analytes from the plates by descending TLC with acetonitrile was noted. The applicability of the TLC method for the concentration of analytes and pretreatment of extracts on the example of real water samples was shown. Using GC-MS with electron impact ionisation, we determined the concentrations of sodium alkylbenzenesulphonates in water sampled in the southern basin of Lake Baikal from a depth of 400 m (0.24±0.02 µg/dm3) and in snowmelt water from the ice of the Krestovka River where it flows into Lake Baikal near the village of Listvyanka (31.1 ± 1.0 µg/dm3).

A study on thermophysical properties of binary mixtures of n-hexane with benzene and some alkyl-substituted benzenes within temperature range (293.15–323.15) K: Experimental and modeling approach

The current work reports densities and sound speeds, and related thermodynamic excess properties, namely excess molar volumes and excess isentropic compressibilities, measured at temperatures from (293.15 to 323.15) K and under atmospheric pressure conditions for binary mixtures of n-hexane with benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene. Redlich-Kister polynomial correlated the thermodynamic excess properties to test the quality of experimental data. Excess properties contributed to understanding molecular interactions between involved molecules and the peculiarities of their packing in the mixture. The Jouyban-Acree model was used to correlate the mixtures' experimental densities, sound speeds, and their related derived properties, namely isobaric thermal expansivities and isentropic compressibilities. The average absolute percentage deviation of the correlated values from the experimental ones was better than 0.036 %, 0.058 %, 0.040 %, and 0.146 % for density, sound speed, isobaric thermal expansivity, and isentropic compressibility, respectively, attesting to the robustness of the Jouyban-Acree correlations. Additionally, the Perturbed Chain Statistical Associating Fluid Theory Equation of State modeled the densities of the current mixtures. Schaaff's Collision Factor Theory and Nomoto's relation were compared for their ability to model the sound speeds of the mixtures. The efficacy of these models was tested by computing the average absolute percentage deviations between experimental and computed values. The modeled densities are reasonably concordant with experimental data, with an overall deviation of 0.02 %. Notably, Nomoto's relation exhibited superior performance over Schaaff's theory in modeling sound speeds of current mixtures, with an overall deviation of 0.33 %. The current findings underline the efficacy and versatility of the used models for thermodynamic modeling in systems of varying complexity.

Kirkwood-Buff Analysis of Binary and Ternary Systems Consisting of Alcohols (Methanol, Ethanol, 1-Propanol, and 2-Propanol), Water, and n-Hexane to Understand the Formation of Surfactant-Free Microemulsions.

Surfactant-free microemulsion (SFME) represents a class of fluid mixtures that can form microheterogeneous structures without detergents, offering an environmentally benign alternative to traditional microemulsions. However, the formation mechanism is still elusive. This work applies the Kirkwood-Buff theory to mixtures of alcohols, water, and n-hexane to elucidate the SFME formation mechanism. To ensure robust calculation of the Kirkwood-Buff integrals (KBIs), we construct a data set of densities and excess free energies of binary and ternary systems. Multiple excess Gibbs free energy models are assessed against this data set to select the most suitable model reproducing the experimental results. In addition, we introduce statistical methods to determine the optimal polynomial order of the Redlich-Kister correlation for the excess volume data. We first validate our methodology in binary systems. Then, we extend the calculation method to ternary mixtures. The KBI calculation results reveal that the alcohol-hexane and water-hexane interactions do not significantly affect SFME formation. In contrast, the interplay among water-water, water-alcohol, and alcohol-alcohol interactions critically influences the ability of a liquid mixture to form SFME structures. SFME systems exhibit the facile formation of water aggregates enveloped by alcohols, whereas non-SFME systems demonstrate homogeneous alcohol/water droplets dispersed in an oil continuous medium.

Development and validation of the chromatography-mass spectrometry technique for polyprenols quantitative assessment

Introduction. Polyprenols are known as a class of natural long-chain isoprenoid alcohols, which are natural bioregulators that directly participate in the synthesis of cell membrane glycoproteins. Their hepatoprotective activity is proven, as well other types of their pharmacological effects are known, which is the reason of significant interest in these substances as a promising medicinal product. It is non-trivial task to determine the sum of polyprenols in extracts as include design and implementation of accurate reproducible analytical methods, which will subsequently be used in standardization.Aim. Development and validation of the chromatographic-mass spectrometric technique for polyprenols identification and their quantitative assessment.Materials and methods. Chromatographic separation of polyprenols was performed by using an HPLC Agilent 1260 Infinity II (Agilent Technologies, США); with the mixture of methanol, n-hexane, propanol-2, and aqueous ammonium acetate solution as eluent in gradient mode. An AB Sciex QTrap® 3200MD (AB Sciex Pte. Ltd., Singapore) triple quadrupole mass spectrometer was used as a detector, with the registration of polyprenols adducts.Results and discussion. The conditions for chromatographic separation and detection of polyprenols were identified. The developed technique was validated for the following characteristics: specificity, limit of detection, limit of quantification, linearity, accuracy, precision, range of application, and stability.Conclusion. It was determined the content of polyprenols in the substance recieved from Ginkgo biloba L. and Picea abies L. The developed technique can be used in the future to assess the content of polyprenols in drug products or pharmaceutical substances.

Anti-lipase Activity of Kemuning (Murraya paniculata) Leaves Extract and Its Fractions

Kemuning (Murraya paniculata) belongs to the Rutaceae family, it grows a lot in tropical areas such as Indonesia. Traditionally, Kemuning leaves are used for weight loss preparations and are believed to contain compounds that can inhibit pancreatic lipase, including flavonoids. This study aimed to reveal the antilipase activity of Kemuning leaves extract and its fractions. The extraction of Kemuning leaves was carried out by maceration with 70% ethanol as solvent. The vacuum liquid chromatography method was used to separate the secondary metabolites in the extract with the stationary phase of silica gel and the eluent mixture of n-hexane, ethyl acetate, and methanol in a gradient manner. Meanwhile, the antilipase activity was tested by colorimetric method, with p-nitrophenyl butyrate as a substrate and orlistat as a positive control. The extract obtained was 19.94% of the weight of the simplicia. The separated extract was collected in 20 flasks and then combined based on the Rf value of the spots observed on thin layer chromatography (TLC) producing 8 fractions (fractions A-H). The percentage yields of fractions A-H were 1.20, 1.33, 1.80, 3.92, 3.57, 4.20, 16.85, and 14.47%, respectively. Antilipase activity was indicated by IC50 values, which were 17.603 ± 1.660 and 108.554 ± 1.660 µg/mL for orlistat and extract, respectively. The antilipase activities of fractions A-H were 130.19 ± 2.90, 119.52 ± 1.95, 96.95 ± 1.81, 91.65 ± 0.78, 95.30 ± 1.46, 114.76 ± 2.87, 127.07 ± 3.56, and 134,04 ± 3.16 µg/mL, respectively. Based on these results, it can be concluded that the extract and its fractions exhibit very strong antilipase activity. Keywords: Murraya paniculata; extract; fraction; antilipase

Separation of 4-substituted 5-methylpiracetam stereoisomers on polysaccharide-based chiral stationary phases

Monitoring of stereoisomer content in samples containing chiral compounds with multiple chiral centers is an important and challenging task in chiral liquid chromatography. 4-Phenyl-5-methylpiracetam, containing two chiral centers, was used as model compound to explore the stereorecognition ability of polysaccharide-based chiral selectors. Initially, the chromatographic behavior of racemic 4-phenyl-5-methylpiracetam on nineteen commercially available polysaccharide-based chiral columns was tested with a mobile phase, consisting of a mixture of ethanol and n-hexane. The obtained results were analysed, and nine chiral phases were selected for further investigation of seven newly synthesized 4-substituted 5-methylpiracetam chiral separations. Our subsequent studies showed that chiral stationary phases based on amylose tris(5-chloro-2-methylphenylcarbamate) and amylose tris[(S)-α-methylbenzylcarbamate] posess higher ability for chiral recognition of stereoisomers of the studied analytes.

A specific chiral HPLC method for lifitegrast and determination of enantiomeric impurity in drug substance, ophthalmic product and stressed samples

Lifitegrast is a lymphocyte function-associated antigen-1 (LFA-1) antagonist used to treat the indications and symptoms associated with dry eye disease (DED), one of the most common ocular surface diseases. Lifitegrast has a chiral center, and the S-enantiomer (S-Lif) is responsible for the therapeutic effects, while the R-enantiomer (R-Lif) lacks efficacy in the treatment of DED. Lifitegrast ophthalmic solution containing 5% lifitegrast was approved by the United States Food and Drug Administration (FDA) in July 2016 for the treatment of DED in patients 17 years of age and older. The objective of this study was to develop a chiral HPLC method for the determination of the enantiomeric impurity of lifitegrast in the drug substance and in the ophthalmic product. In addition, we aimed to investigate the effect of stress and stability conditions on the enantiomeric purity of lifitegrast in both drug substance and ophthalmic solution. During the method development studies, four known lifitegrast impurities (Lif. Imp. A-D) and stressed lifitegrast samples were injected to ensure the specificity of the developed method. The enantiomers of lifitegrast are well separated with a resolution of higher than 4.0. They are also well separated from the peaks of the diluent, impurities, and the placebo used to prepare the ophthalmic solution without interference in 20 min. Chiral separation was achieved using a Chiralpak AD-H column (250 × 4.6 mm, 5.0 μm) at 40 °C with a mobile phase consisting of a mixture of n-hexane, 2-propanol, and formic acid (500:500:2, v/v/v) at a flow rate of 1.0 mL/min and a detection wavelength of 260 nm. Methanol was used as the diluent, and the drug substance solution was found to be stable for 48 h at 15 °C. The optimized chiral HPLC method for lifitegrast was validated according to ICH Q2, and the calibration curves showed excellent linearity for R-Lif (0.0369 – 1.816 µg/mL). This is the first stability-indicating, specific / selective, sensitive, linear, precise, accurate, and robust chiral HPLC method for the determination of R-Lif in S-Lif. The amount of enantiomeric impurity R-Lif in S-Lif increased under all stress and photostability test conditions without exceeding the acceptable impurity limit, with the most significant increase observed at elevated temperatures (105 °C) for both the drug substance in powder form and the ophthalmic drug solution.

Mono-cyclopentyl substituted [1,3,4]thiadiazole thione tautomer: study of the spectroscopic, geometric, thermal, and biological properties

Regarding the importance of thiol-thione tautomer structure and the existence of hydrogen bonding in thione tautomer structure and its effect on geometric, physicochemical, and biological properties, mono-cyclopentyl-substituted bismuthiol was synthesized via a telescopic process in a green medium. The pure product was characterized by physical and spectroscopic techniques. The suitable crystals for single crystal study were obtained after trying different solvents and mixed solvents, and long clear needle-like crystals could be isolated from a mixture of n-hexane and ethyl acetate (volume ratio of 8:2). The FTIR spectra of bismuthiol, 2,5-bis-cyclopentylsulfanyl-[1,3,4]thiadiazole, and 5-cyclopentylsulfanyl-3H-[1,3,4]thiadiazole-2-thione were studied to define the characteristic wavenumbers of thiol and thione structures. A possible hyper-conjugative interaction between the S–H and π bond of C=N, the existence of C=S and C–N–H. and stability of thione structure was demonstrated for the new product, which supports our prediction of thione or thiol structure using the study of IR spectra. Furthermore, the influence of change in 1,3,4-thiadiazol ring and the presence N–H functional group of thione structure on the transition phases and thermal stability of bismuthiol, bis-cyclopentyl-substituted, and mono-cyclopentyl-substituted bismuthiol were investigated using TGA/DTA and DSC profile analysis. The SwissADME tool was employed to predict the biocheminformatic information of bismuthiol, bis- and mono-cyclopentyl-substituted bismuthiols, which displayed high potential of all 1,3,4-thiadizole derivatives in pharmaceutical and medicine areas. Finally, an in vitro antibacterial activity of the mono- and bis-cyclopentyl substituted bismuthiol against the gram-negative (Escherichia coli ATCC 25922) and gram-positive (Staphylococcus aureus ATCC 25923) bacterial species was conducted by the disk diffusion method with cefazolin as a blank antibiotic. The results showed superior antibacterial efficiency of both derivatives.

Forecasting mixture composition in the extractive distillation of n-hexane and ethyl acetate with n-methyl-2-pyrrolidone through ANN for a preliminary energy assessment

&lt;abstract&gt; &lt;p&gt;We developed an artificial neural network (ANN) to predict mole fractions in the extractive distillation of an n-hexane and ethyl acetate mixture, which are common organic solvents in chemical and pharmaceutical manufacturing. The ANN was trained on 250 data pairs from simulations in DWSIM software. The training dataset consisted of four inputs: Feed flow inlet (T1-F), Feed Stream Mass Flow temperature pressure (FM1-F), Make-up stream mass flow (FM2-MU), and ERC tower reflux ratio (RR-ERC). The ANN demonstrated the ability to forecast four output variables (neurons): Mole fraction of n-hexane in the distillate of EDC (XHE-EDC), Mole fraction of N-methyl-2 pyrrolidone in the bottom of EDC (XNMP-EDC), Mole fraction of ethyl acetate in the distillate of ERC (XEA-ERC), and Mole fraction of N-methyl-2 pyrrolidone in the bottom of ERC (XNMP-ERC).The ANN architecture contained 80 hidden neurons. Bayesian regularization training yielded high prediction accuracy (MSE = 2.56 × 10&lt;sup&gt;–7&lt;/sup&gt;, R = 0.9999). ANOVA statistical validation indicated that ANN could reliably forecast mole fractions. By integrating this ANN into process control systems, manufacturers could enhance product quality, decrease operating expenses, and mitigate composition variability risks. This data-driven modeling approach may also optimize energy consumption when combined with genetic algorithms. Further research will validate predictions onsite and explore hybrid energy optimization technologies.&lt;/p&gt; &lt;/abstract&gt;

Analysis of Organic Compounds in Residual from Wheat Stalk Depolymerized in Supercritical Methanol

Liquefaction of biomass is a practical source of clean liquid fuel and possible source of value-added chemicals. But if solid residual formed during liqufaction can’t be properly handled, it will be a new environmental problem. In this study, we use n-hexane and carbon disulfide to extract (under ultrasonic) the biomass residual from wheat stalk depolymerized in supercritical methanol. In the fraction extracted by n-hexane, Oxy-compounds and compounds containing benzene ring are present in high concentration. The fraction extracted by carbon disulfide is separated by column chromatography. The first sub-fraction eluted by n-hexane only detected three compounds, benzenethiol, diphenylmethane and diphenyldisulfide. The second sub-fraction eluted by n-hexane is mainly alkyl-benzenes and alkyl-cyclohexanes. Nine saturated fatty hydrocarbons from C21 to C29 are eluted in the sub-fraction eluted by mixture of n-hexane and benzene.

Solubility measurement and correlation for γ-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane in four binary solvents (ethyl acetate + n-hexane, n-heptane, n-octane, iso-octane) at temperatures from 283.15 K to 323.15 K

The solubility of γ-CL-20 in four binary solvents (n-hexane, n-heptane, n-octane, iso-octane mixtures of n-hexane, n-heptane, n-octane and iso-octane mixed with various mole fractions of ethyl acetate) was determined using the gravimetric method at temperatures ranging from 283.15 K to 323.15 K under atmospheric pressure in this work. The experimental solubility data of γ-CL-20 were correlated and fitted to the thermodynamic models such as the modified Apelblat equation, van’t Hoff equation, CNIBS/R-K equation, and Jouyban-Acree model. In the temperature range of 283.15 K–323.15 K. The solubility of γ-CL-20 declines monotonically and slowly with increasing temperature and the temperature dependence is invisible in all of the solution systems. Additionally, it demonstrates that the solubility in binary solvent combinations rises as the ethyl acetate (EtOAc) mole fraction does.

Double step method in lipid extraction from biomass &lt;i&gt;Aurantiochytrium sp&lt;/i&gt; powder

&lt;p&gt;&lt;em&gt;&lt;span&gt;Aurantiochytrium sp&lt;/span&gt;&lt;/em&gt;&lt;span&gt; is a marine microalgae that is rich in lipids. Extraction of lipids from microalgae requires effort to select a suitable solvent and extraction method. This research used a double-step extraction method to study a mixture of n-hexane and methanol as a solvent. The variables studied were stirring time, the n-hexane to methanol (H/M) mixture ratio, and the solvent-to-biomass ratio (S/B). This research concluded that an optimum stirring time was 30 min, and a mixture of n-hexane and methanol solvents with a volume ratio of 1:1 is optimum. The optimum solvent-to-biomass ratio was S/B=20 mL/g dry microalgae. Under these conditions, the yield of oil was 83.88%. Double-step extraction can increase the yield by 10-40%.&lt;/span&gt;&lt;/p&gt;