Search

Compositions of coexisting phases (liquid–liquid equilibrium), solubility, and critical states for the quaternary acetic acid–n-butyl alcohol–n-butyl acetate–water system were carried out at 328.15...

In the field of industrial crystallization, liquid–liquid phase separation (LLPS) easily makes the crystallization process into an uncontrollable state, making it extremely difficult for people to ...

2,2-Difluoroethanol (DFE) is an important aliphatic fluorine-containing chemical intermediate. During its preparation, an azeotropic mixture of DFE and water is formed. To recover DFE from its aque...

The adsorption of two-dimensional (2-D) graphene oxide (GO) nanosheets at liquid-liquid interfaces has broad technological implications from functional material preparations to oil-water emulsification. Molecular-level understanding of the adsorption thermodynamics and the interfacial behavior is of great significance. Here, the adsorption free energy of GO nanosheets at the water-cyclohexane system was simulated, in which the effect of oxygen-containing groups and deprotonation has been investigated. It was observed that the neutral GO (GO-COOH) has obvious interfacial activity with a reduction of interfacial tension, while the deprotonated GO (GO-COO-) shows a weak interface affinity. There exists an optimal oxidization degree that could cause the best interfacial stability, which is attributed to the balance of interfacial hydrophilic-hydrophobic interactions. The interaction arising from water is the main factor determining interfacial activity. The interfacial morphology and dynamics of GO nanosheets have also been simulated, in which an anisotropic 2-D translation and rotation along the interface were revealed. Our simulation results provide new insight into the adsorption mechanism and dynamics behavior of GO at the oil-water interface.

In the present study, liquid–liquid flow dynamics are compared in three different geometries experimentally. These are straight glass capillary, serpentine geometry made of glass capillary, and ser...

Intrinsically disordered proteins (IDPs) populate an ensemble of dynamic conformations, making their structural characterization by experiments challenging. Many IDPs undergo liquid-liquid phase separation into dense membraneless organelles with myriad cellular functions. Multivalent interactions in low-complexity IDPs promote the formation of these subcellular coacervates. While solution NMR, Förster resonance energy transfer (FRET), and small-angle X-ray scattering (SAXS) studies on IDPs have their own challenges, recent computational methods draw a rational trade-off to characterize the driving forces underlying phase separation. In this Perspective, we critically evaluate the scope of approximation-free field theoretic simulations, well-tempered ensemble methods, enhanced sampling techniques, coarse-grained force fields, and slab simulation approaches to offer an improved understanding of phase separation. A synergy between simulation length scale and model resolution would reduce the existing caveats and enable theories of polymer physics to elucidate finer details of liquid-liquid phase separation (LLPS). These computational advances offer promise for rigorous characterization of the IDP proteome and designing peptides with tunable material and self-assembly properties.

The approach coupling computational fluid dynamics and a population balance model (PBM) was adopted to simulate the hydraulic performance of liquid–liquid dispersions in a pump-mixer. Behaviors of ...

Liquid–liquid equilibrium data were obtained for aqueous two-phase system (ATPS) composed of [poly(ethylene oxide) (PEO1500), poly(propylene oxide) (PPO425), poly(ethylene oxide)11–poly(propylene o...

Liquid-liquid two-phase flows are central to solvent extraction processes. In a columnar solvent extraction contactor, the turn-down ratio can be increased by imposing oscillatory flow over steady ...

In this work, the Dispersive Liquid-Liquid Microextraction (DLLME) method has intensified the extraction of Zinc from aqueous solution utilizing 1-butyl-3-methylimidazolium hexafluorophosphate [BMI...

An efficient, rapid, simple and repeatable sample preparation method based on pressurised liquid extraction combined with deep eutectic solvent-based dispersive liquid–liquid microextraction was de...

A simple, sensitive and matrix-effect free analytical method for simultaneous determination of Cd, Hg and Pb in drug samples (i.e., commercial dosage tablets) by inductively coupled plasma optical emission spectrometry (ICP OES) has been developed. According to the United States Pharmacopeia (USP) Chapter 232, those metals are considered elemental impurities from class 1 and they must be assessed in pharmaceutical production as well as in quality control evaluation. In order to increase the sensitivity of the analysis, dispersive liquid–liquid microextraction (DLLME) was performed and seven factors affecting analyte extraction were optimized by multivariate analysis. A microvolume of analyte enriched phase was directly introduced into the plasma using a multi-nebulizer, providing a high enrichment factor. When compared to conventional ICP OES analysis, DLLME improves the limit of quantitation (LOQ) values on average 40-fold for all analytes. Consequently, LOQ values were significantly lower than their permissible daily exposure limits for oral drugs. Accuracy was evaluated by addition and recovery experiments following USP recommendations in eight commercial drug samples. Recovery and RSD values were within the range of 90–108% and 1–9%, respectively. The authors are grateful to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, process no. 141634/2017-0, 202722/2019-8, 305201/2018-2 and 428558/2018-6), the Regional Government of Valencia (Spain) (PROMETEO/2018/087) for the financial support, Agilent Technologies Inc. for the loan of the ICP OES spectrometer, and Ingeniatrics for the MultiNeb® provided. This study was financed in part by the Coordenaçao de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. The authors extend their appreciation to Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society.

G-quadruplex DNA interacts with the N-terminal intrinsically disordered domain of the DEAD-box helicase Ded1p, diminishing RNA unwinding activity but enhancing liquid–liquid phase separation of Ded1p in vitro and in cells. The data highlight multifaceted effects of quadruplex DNA on an enzyme with intrinsically disordered domains., G-quadruplex (G4) DNA inhibits RNA unwinding activity but promotes liquid–liquid phase separation of the DEAD-box helicase Ded1p in vitro and in cells. This highlights multifaceted effects of G4DNA on an enzyme with intrinsically disordered domains.

Liquid–liquid phase separation (LLPS) plays an important role in a variety of biological processes and is also associated with protein aggregation in neurodegenerative diseases. Quantification of LLPS is necessary to elucidate the mechanism of LLPS and the subsequent aggregation process. In this study, we showed that ataxin-3, which is associated with Machado–Joseph disease, exhibits LLPS in an intracellular crowding environment mimicked by biopolymers, and proposed that a single droplet formed in LLPS can be quantified using Raman microscopy in a label-free manner. We succeeded in evaluating the protein concentration and identifying the components present inside and outside a droplet using the O–H stretching band of water as an internal intensity standard. Only water and protein were detected to be present inside droplets with crowding agents remaining outside. The protein concentration in a droplet was dependent on the crowding environment, indicating that the protein concentration and intracellular environment should be considered when investigating LLPS. Raman microscopy has the potential to become a powerful technique for clarifying the chemical nature of LLPS and its relationship with protein aggregation., Liquid–liquid phase separation (LLPS) plays an important role in a variety of biological processes. We have established a method to quantify a single droplet formed by LLPS using the Raman band of water as an internal standard.

This work describes a rapid solvent-minimized process to effectively determine four common paraben preservatives (methyl-, ethyl-, propyl- and butyl-paraben) in surface water samples. The method involved the use of a combination of a novel ultrasound-assisted simultaneous-silylation within dispersive liquid–liquid microextraction (UASS-DLLME) with detection by gas chromatography-tandem mass spectrometry (GC-MS/MS). To overcome the challenges related to the different experimental conditions, multivariate experimental design approaches conducted by means of a multilevel categorical design and a Box–Behnken design were utilized to screen and optimize parameters that have significant influences on the efficiency of silylation and extraction. The method was then validated and shown to provide low limits of quantitation (LOQs; 1–5 ng L−1), high precision (3–11%), and satisfactory mean spiked recoveries (accuracy; 79–101%). Upon analyzing samples of surface water obtained from the field, we found that, in total, there was a relatively high concentration of the target parabens ranging from 200 to 1389 ng L−1. The sources of the elevated levels of these parabens may be from the release of untreated municipal wastewater in this region, and also due to the widespread application of parabens in personal care and food products.

DBP, one of the phthalic acid esters (PAEs), is known as an endocrine disruptor and is toxic to humans in abnormal concentrations. Here, a high-density and ordered SERS substrate based on the self-assembly of triangular Ag nanoplate (TAgNP) arrays is developed for DBP detection. Benefiting from the ordered arrangement and sharp corners of TAgNPS, the arrays can provide sufficient and uniform hotspots for reproducible and highly active SERS effects. Using Rhodamine 6G (R6G) as a reporter molecule, the SERS enhancement factor (EF) of the TAgNP arrays was found to be as high as 1.2 × 107 and the relative standard deviation was 6.56%. As a trial for practical applications, the TAgNP array substrates were used for the detection of dibutyl phthalate (DBP) in edible oils. In this assay, edible oil samples were added to hexane as an organic phase for the formation of the TAgNP arrays, which caused DBP to be loaded at hotspots. DBP in edible oils could be identified at concentrations as low as 10-7 M. This SERS substrate based on the TAgNP arrays has great potential applications in the high sensitivity and reproducible detection of contaminants in food.

Background: Aflatoxin B1 is a secondary toxic metabolite produced by several aspergillus species. This study was conducted to determine the presence of aflatoxin in tomato paste samples. Methods: A total of 30 tomato pastes were analyzed for Aflatoxin B1 contamination via HPLC-FLD. Analyte extraction was done by dispersive liquid-liquid microextraction. Results: The limit of detection (LOD) and limit of quantitation (LOQ) were 0.14 and 0.44 µg/kg, respectively. The recovery rates ranged from 91 to 94%. The findings showed all samples were contaminated with Aflatoxin B1 and the average concentration was 1.1 ± 0.02 µg/kg. The amount of aflatoxin B1 in 6 samples was higher than the limit set by the European Union. Conclusion: The proposed method was successfully applied to the analysis of tomato paste samples with quantitative results. The main advantages of the developed method include its simplicity in operation, rapid achievement of a very high sample, and low cost.

Putrescine and cadaverine are biogenic amines that serve as potential biomarkers for several types of cancers and monitoring food quality. Electrochemical sensing of putrescine and cadaverine by non-enzymatic routes remains a challenge because of their inertness at unmodified electrode surfaces and hence a liquid-liquid interface strategy has been employed for their detection. In the present study, electrochemical sensing of cadaverine and putrescine has been demonstrated by simple and facilitated ion-transfer processes using a liquid-liquid microinterface supported by a microcapillary. A microinterface was constructed in different configurations by varying the aqueous phase composition in the absence and presence of dibenzo-18-crown-6, and the ion-transfer ability of putrescine and cadaverine was studied in these configurations. A peak shaped voltammogram was observed in the backward scan, due to the linear diffusion of putrescine and cadaverine from the organic to the aqueous phase. The detection ability in the presence of dibenzo-18-crown-6 was observed in the concentration ranges of 0.25-25 μM and 0.25-40 μM for putrescine and cadaverine with detection limits of 0.11 and 0.17 μM respectively. In the presence of dibenzo-18-crown-6, the electrochemical sensing of putrescine and cadaverine was more pronounced compared to the simple ion-transfer process.

Liquid-liquid phase separation (LLPS), a type of phase transition that is important in organisms, is a unique means of forming biomolecular condensates. LLPS plays a significant role in transcription, genome organisation, immune response and cell signaling, and its dysregulation may cause neurodegenerative diseases and cancers. Exploring the regulatory mechanism of LLPS contributes to the understanding of the pathogenic mechanism of abnormal phase transition and enables potential therapeutic targets to be proposed. Many factors have been found to regulate LLPS, of which post-translational modification (PTM) is among the most important. PTMs can change the structure, charge, hydrophobicity and other properties of the proteins involved in phase separation and thereby affect the phase transition behaviour. In this review, we discuss LLPS and the regulatory effects of PTMs, RNA and molecular chaperones in a phase separation system. We introduce several common PTMs (including phosphorylation, arginine methylation, arginine citrullination, acetylation, ubiquitination and poly(ADP-ribosyl)ation), highlight recent advances regarding their roles in LLPS and describe the regulatory mechanisms behind these features. This review provides a detailed overview of the field that will help further the understanding of and interventions in LLPS.

In Parkinson's disease with dementia, up to 50% of patients develop a high number of tau‐containing neurofibrillary tangles. Tau‐based pathologies may thus act synergistically with the α‐synuclein pathology to confer a worse prognosis. A better understanding of the relationship between the two distinct pathologies is therefore required. Liquid–liquid phase separation (LLPS) of proteins has recently been shown to be important for protein aggregation involved in amyotrophic lateral sclerosis, whereas tau phase separation has been linked to Alzheimer's disease. We therefore investigated the interaction of α‐synuclein with tau and its consequences on tau LLPS. We find α‐synuclein to have a low propensity for both, self‐coacervation and RNA‐mediated LLPS at pH 7.4. However, full‐length but not carboxy‐terminally truncated α‐synuclein efficiently partitions into tau/RNA droplets. We further demonstrate that Cdk2‐phosphorylation promotes the concentration of tau into RNA‐induced droplets, but at the same time decreases the amount of α‐synuclein inside the droplets. NMR spectroscopy reveals that the interaction of the carboxy‐terminal domain of α‐synuclein with the proline‐rich region P2 of tau is required for the recruitment of α‐synuclein into tau droplets. The combined data suggest that the concentration of α‐synuclein into tau‐associated condensates can contribute to synergistic aSyn/tau pathologies.

Hydrocyclones are widely used in industry and CFD has been used to compute them. Reynolds stress turbulence models (RSM), which are computationally costly and oftentimes hard to converge, are often...

In this paper, novel high extraction efficiency hydrophobic eutectic solvents (DESs), n-octanoic acid as a hydrogen bond donor (HBD) and menthol as a hydrogen bond acceptor (HBA), were selected from five hydrophobic DESs to extract trace diphenylamine (DPA) in fruits apple, pear and orange under ultrasonic-assisted liquid-liquid micro-extraction (UA-LLME) technology before high-performance liquid chromatography (HPLC) analysis. Working parameters such as the DESs type, molar ratio, extractant volume, and ultrasonic time of the LLME hydrophobic DESs technology were optimised. Average recoveries between 96% and 108% were obtained on actual samples. This method gave lower detection limit (LOD) than other existing methods due to combining the high-efficiency extraction of hydrophobic DES and high sensitivity of fluorescence detector. This method was sensitive and eco-friendly, and can be used for the determination of trace components in fruits.

In this study, four ternary liquid–liquid equilibrium systems containing a solvent, furfural, and water were investigated by performing liquid–liquid equilibrium measurements at two different tempe...

From the liquid–liquid equilibrium (LLE) data of a linear polymer, an investigation of the Sanchez and Lacombe equation of state (SL-EOS) is performed with the goal of describing the swelling of th...

The ternary liquid–liquid equilibrium (LLE) data for cyclohexanone (CYC) + phenol + water were determined at T = (298.15, 313.15, and 323.15) K and atmospheric pressure. The distribution coefficien...

Biological materials represent a major source of inspiration to engineer protein-based polymers that can replicate the properties of living systems. Combined with our ability to control the molecular structure of proteins at the single amino acid level, this results in a vast array of attractive possibilities for materials science, an interest that is undeniably related to simplified procedures in gene synthesis, cloning, and biotechnological production. In parallel, it has been increasingly appreciated that living organisms exploit liquid-liquid phase separation (LLPS) to fabricate extracellular structures. In this article, we discuss the central role of protein LLPS in the fabrication of selected biological structures, including biological adhesives and hard biomolecular composites, and how physicochemical lessons from these systems are being replicated in synthetic analogs. Recent translational applications of protein LLPS are highlighted, notably aqueous-resistant adhesives, stimuli-responsive therapeutics carriers, and matrix materials for green structural composites. Ministry of Education (MOE) Nanyang Technological University National Research Foundation (NRF) Published version A.M. acknowledges financial support from the Singapore Ministry of Education (Grant Nos. MOE 2018-T2–1-043 and MOE 2019-T3-1-012) and from the Strategic Initiative on Biomimetic and Sustainable Materials (IBSM) at NTU. J.Y. acknowledges financial support from the Singapore National Research Foundation Fellowship (NRF-NRFF11–2019-0004).

This paper describes a novel method for the sensitive determination of imidacloprid using homogeneous liquid−liquid microextraction via flotation assistance (HLLME-FA) in water samples. After the extraction procedure, low density organic solvent was separated by air flotation. Various parameters affecting the extraction efficiencies such as the types of extraction and homogeneous solvents, the volumes of extraction and homogeneous solvents, extraction time and ionic strength were studied. Under the optimized conditions, the detection limit of imidacloprid was 0.02 µg/L. The experimental results indicated that there was good linearity (r2 = 0.9995) over the range of 0.25–500 µg/L. The relative standard deviation (n = 3) at the concentration level of 1.0 µg/L of imidacloprid in sea, well and river water samples was 11.1%. The proposed method has been successfully applied to the determination of imidacloprid in real water samples.

The main bitter constituents of sambiloto (Androgaphis paniculata (Burm., F) Ness) are diterpene lactones, namely andrographolide and deoxyandrographolide which have been reported to have antidiabetic, cytotoxic, antiatherosclerosis, anti-inflammatory, and antimicrobial activity. There are many studies that performed the isolation of deoxyandrographolide and andrographolide from A. paniculata herbs, but most of them included several steps that make them not efficient. This research was conducted to do an isolation of deoxyandrographolide and andrographolide through liquid-liquid fractionation (LLF) due to its simplicity, low cost, and time efficient. The extraction of deoxyandrographolide and andrographolide from the herbs was carried out using chloroform as the solvent by using Soxhlet apparatus, and LLF was performed to isolate the compounds. The identities of the compounds were confirmed by TLC scanner compared to its standard references. Hence, these present methods were successfully isolated and determined deoxyandrographolide and andrographolide of A. paniculata. The compounds were also showed relatively moderate cytotoxicity on 3T3-L1 cell lines using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, with LC50 of deoxyandrographolide and andrographolide; 29.3173 µg/mL and 37.7011 µg/mL, respectively.

This work comprises the separation of an azeotropic mixture (hexane/ethyl acetate) with two different ionic liquids, viz, (1-ethyl-3-methylimidazolium tetrafluoroborate, [EMIM][BF4], and 1-ethyl-3-...

Liquid-liquid phase separation (LLPS) of proteins that leads to formation of membrane-less organelles is critical to many biochemical processes in the cell. However, dysregulated LLPS can also facilitate aberrant phase transitions and lead to protein aggregation and disease. Accordingly, there is great interest in identifying small molecules that modulate LLPS. Here, we demonstrate that 4,4’-dianilino-1,1’-binaphthyl-5,5’-disulfonic acid (bis-ANS) and similar compounds are potent biphasic modulators of protein LLPS. Depending on context, bis-ANS can both induce LLPS de novo as well as prevent formation of homotypic liquid droplets. Our study also reveals the mechanisms by which bis-ANS and related compounds modulate LLPS and identify key chemical features of small molecules required for this activity. These findings may provide a foundation for the rational design of small molecule modulators of LLPS with therapeutic value., Dysregulated liquid-liquid phase separation (LLPS) of proteins can facilitate aberrant phase transitions and lead to protein aggregation and disease. Here, authors demonstrate that 4,4’-dianilino-1,1’-binaphthyl-5,5’-disulfonic acid (bis-ANS) and similar compounds are potent biphasic modulators of protein LLPS.

Published data on various versions of the homogeneous liquid–liquid microextraction (HLLME) of organic compounds are generalized and systematized, and a classification of these versions is given. The main HLLME procedures are discussed. Examples of the application of HLLME to the separation of organic compounds in the analysis of environmental samples, food products, and biological fluids are given.

The types of the steady states for a continuous stirred-tank reactor are studied depending on the process parameters, in particular, a parameter not affecting the position of the steady states, by way of example of a liquid–liquid heterogeneous system, in which an exothermic reaction proceeds. It is shown that the change in the coarse steady states occurs through degenerate steady states.

In this article, Aspen Plus was used to simulate a process for separating the mixture of decanol + undecanol + tetradecane + pentadecane to obtain decanol + undecanol product and tetradecane + pent...

The dispersive liquid–liquid microextraction (DLLME) was evaluated as a strategy to improve the MIP OES sensitivity for molybdenum determination in lamb meat. Initially, the dispersive (methanol) and extracting (tetrachloromethane) solvents were selected based on a mixture design. The best results were achieved with methanol and carbon tetrachloride as dispersive and extracting solvent, respectively. The operational parameters, such as pH, volume of dispersive and extractant solvents, and complexing agent concentration (8-hydroxyquinoline) were optimized using a Box-Behnken design. The optimal conditions were established as pH 3.8, 90 μL of carbon tetrachloride, 480 μL of methanol, and 1.09 mmol L-1 of 8-hydroxyquinoline. Besides, the use of external gas module control (EGCM) was explored to minimize the matrix effects caused by the organic solvent introduction. The accuracy of the proposed method was estimated employing a certificate reference material (bovine liver, NIST 1577c) and the obtained recovery was 92%. The limit of detection was found to be 0.20 μg g-1, and the enrichment factor was 4.5. The DLLME-MIP OES was applied for six samples of lamb meat, and the results compared to ICP-MS presented no statistical difference. Therefore, the proposed method showed satisfactory accuracy and suitable sensitivity.

The separation of cyclopentanone from aqueous solutions with recommended (propan-2-yl) benzene (cumene) solvent was investigated at different temperatures of 293.2, 298.2, and 308.2 K and with the ...

The synergistic extraction of phenol from aqueous solution with diisopropyl ether (DIPE) and n-pentanol was studied at 298.15 K under 101.3 kPa. The liquid–liquid equilibrium (LLE) data of the quat...

Ternary liquid–liquid equilibrium (LLE) data were measured for the {water + phosphoric acid + aromatic esters (benzyl acetate, benzyl benzoate, dimethyl phthalate, and diethyl phthalate)} systems a...