Liquid Extraction Research Articles

Validation of sibutramine and phenolphthalein determination by HPLC-PDA in natural dietary supplements for body-weight reduction

The worldwide demand for natural dietary supplements for body-weight reduction is increasing, because they are commonly believed to be safe. However, the abundance and diversity of available dietary supplements impede their quality control, potentially posing multiple health risks. A simple and cost-effective procedure involving high-performance liquid chromatography photodiode array detector (HPLC-PDA) and homogeneous liquid– liquid extraction (LLE) of samples were applied to analyze simultaneously sibutramine and phenolphthalein in natural dietary supplements used for body-weight reduction. The recoveries obtained ranged from 91.87% to 96.46%. The limits of detection and quantification were 0.33 μg/mL and 1 μg/mL, respectively. The phenolphthalein and sibutramine contents were in the range of 0.009-5.601 mg/tablet and 0.005-4.409 mg/ tablet, respectively. The results showed that the proposed HPLC-PDA method was precise and accurate. It was simple to apply to identify and quantify these and other adulterants in natural dietary supplements.

Comparison of extraction process, physicochemical properties, and in vitro digestion characteristics of chia seed mucilage polysaccharide.

The study explored five (acidic, alkaline, heating, ionic liquid, and urea solvent) extraction methods' effects on chia seed mucilage polysaccharide (CSM), an anionic polymeric macromolecule, regarding its physicochemical properties, structure, and digestion behavior. The results showed that extraction parameters have a considerable effect on modulating CSM properties. Significant differences emerged in the predominant chemical compositions: the carbohydrates and protein content ranged from 49.20±0.06% to 85.81±0.03%, and 3.20±0.13% to 14.57±0.30%, respectively. The structural analysis revealed that alkaline heating treatment facilitated the formation of protein-polysaccharide conjugates, resulting in reduced particle size, enhanced ζ-potential, and improved thermal stability (194.72±2.19J/g). The crystallinity of CSM varied, peaking at 42.9±0.22% without pH adjustment and heating. CSM extracted using 6M urea exhibited the lowest protein content, and crystallinity (25.50±0.09%), coupled with the highest gastrointestinal digestion rate and poorest thermal stability (with a carbohydrate degradability of 24.223±1.78% and enthalpy value of 62.82±0.32J/g). The CSM obtained under alkaline heating showed minute particles (201.1±10.35μm), the highest ζ-potential absolute value (20.95±2.28mV), and robust thermal stability (194.72±2.19J/g of enthalpy value), which is ideal for stabilizing emulsions or encapsulating thermolabile substances. Additionally, compared to monovalent cations‑sodium ions, divalent cations‑magnesium ions, is more tend to aggregate the CSM structure, resulting in larger molecular particles and a higher protein content. Elevated ionic concentration further diminished thermal stability. These findings suggest that CSM is a customizable, multi-purpose polymer that can be extracted in various ways based on the end-product requirements.

Synchronization of extraction and chromatographic conditions of diverse physicochemical behavior of pseudoephedrine, loratadine and desloratadine for their simultaneous determination in human plasma: Application to pharmacokinetic study

A selective, sensitive, and rapid LC-MS/MS method has been developed, optimized, and validated for the simultaneous determination of pseudoephedrine (PSE), loratadine (LOR), and LOR active metabolite, desloratadine (DES) in K3EDTA human plasma. A simple liquid–liquid extraction method was adopted for extraction of the 3 analytes and their internal standards; chlorpheniramine (CLP), loratadine D4 (LOR-D4), and desloratadine D4 (DES-D4), respectively, giving consistent recovery results (78.38––88.23 %) using diethyl ether: dichloromethane (80:20, v/v) as the extraction solvent. The chromatographic separation was challenging due to the polarity differences between PES, which is more polar, and LOR and DES, which are less polar that affected their physicochemical properties including the retention of the drugs on C18 column. The separation was achieved using of isocratic elution of 20 mM ammonium formate and 2 mM trifluoracetic acid ammonium salt: acetonitrile containing 0.15 % formic acid (12:88, v/v) as a mobile phase pumped onto a Supelco Discovery® C18 (4.6 mm x 100 mm, 5 µm) at 35 °C with a flow rate of 0.8 mL/min. The use of trifluoracetic acid ammonium salt as an ion pair reagent in the selected mobile phase allowed good retention of the polar PSE on the used C18 column with a reasonable retention time. Positive Electrospray ionization was employed followed by detection using a tandem mass spectrometer in multiple reactions monitoring (MRM) mode. The sample analysis of this study was conducted in compliance with ICH guideline M10 on bioanalytical method validation and study sample analysis. The method was linear over the concentration range of (4–1200) ng/mL for PSE, (50–15000) pg/mL for both LOR, and DES. The developed method was accurate (91.14–110.30 %), precise (0.53–7.86 %), and was applied to study the pharmacokinetic profile of the cited drugs in the plasma of healthy human volunteers after single oral administration of the fixed-dose combination Claritin D® tablet, (240/10 mg) of PSE, and LOR, respectively.

Biological Activities and Phytochemical Constituents in the Stimulatory Potential of Tithonia diversifolia Fermented Extracts: A Review

The world food production must increase by 70% to feed this massive population through the use of chemical inputs in the new millennium. Crop culture is challenged by parasitic constraints, seedlings unavailability and soil fertility issues, which can severely reduce productivity. However, the repeated uses of chemical inputs negatively impact environment, plant and human health equilibrium. So, pathogen resistance, seedling quality and plant fertilization are severely concerned over the course of time. In this context, the use of a plant extract as Tithonia diversifolia, could be a good natural alternative to chemical inputs stimulants. The lack of knowledge of phytochemical constituents involving biologicals activities in liquid form of T. diversifolia extract, need to be improved to ensure their labeling. This study reviews biological activities and main phytochemical constituents in the stimulatory potential of T. diversifolia fermented liquid extracts. The stimulatory potential bio-efficacy of T. diversifolia extracts concerns the combination of biocontrol and green fertilizer effects. The green manure is conducted by watering or mulching on varied crops, such as rice, maize or plantain banana. Existing concerns are to expand the information amounts concerning the stimulating properties of the bioactive compounds contained in the fermented liquid extracts. It would be a key to fully demonstrate their effectiveness in stimulating the mechanism of plant growth and the protection against phytopathogens. However, this review updates on the challenge of the possibility to characterize the major bioactive compounds in the extracts. The other challenge of this current work is to suggest an eco-responsible and biological labeling product based on T. diversifolia fermented liquid extract.

Supercritical fluid extraction prior pulsed electric fields to improve high-added-value compounds recovery from salmon side streams: Evaluation of protein, bioactive peptides and minerals

A sequential extraction process combining supercritical fluid extraction (SFE: 25.0 MPa, 75 min, 50.0 °C, and 10.0 mL/min flow) with pulsed electric fields (PEF: 3.0 kV/cm, 300 kJ/kg for head/backbones, 124.8 kJ/kg for viscera) or conventional extraction (CE: 60 min, 300 rpm) was optimized to enhance the recovery of high-added-value compounds, including proteins, bioactive peptides, minerals, heavy metals, and total antioxidant capacity (TAC) from salmon side streams. Protein levels increased notably with PEF, particularly in viscera liquid extracts, reaching 15.5 g/100 g. Bioactive peptides displayed anti-inflammatory, immunomodulatory, anticancer, hypolipidemic, and antithrombotic potential. Viscera liquid extracts showed high TAC (402.8 and 3263.6 μM). ICP-MS analysis revealed PEF treatment helps solid matrices retaining more minerals and heavy metals. Principal component analysis (PCA) on proteins, peptides, minerals, and heavy metals elucidated PEF's impact, identifying two main components affecting the salmon matrix and extract composition.

Seaweed liquid extract AS novel sustainable solutions for phycobioremediation plant germination, and feed additive for marine invertebrate copepod

Several studies have shown the importance of using seaweed liquid extract (True-Algae-Max, TAM) as a fish feed additive, and fish-water conditioner. In addition, TAM has demonstrated significant growth improvement when used as a plant growth biostimulant. This study investigates whether seaweed liquid extract (TAM) can achieve good results in new experimental fields such as chromium remediation, plant germination, and live feed supplementation for marine invertebrate Copepod (Oithona nana). In this study, several doses of TAM were tested, for the first time, for their impact on the remediation of chromium (Cr6+) ions from aqueous solutions and as an aqua feed additive for marine copepods (Oithona nana). In addition, it has been tested as promising for the seed germination of Fenugreek (Trigonella foenum-graecum) and Faba bean (Vicia faba L.). The most important factors influencing the removal (%) of Cr6+, identified using a two-level Plackett–Burman factorial design, were selected for additional optimization utilizing a rotatable central composite design. The maximum adsorption of Cr6+ was 93.65% under ideal operating circumstances, which included an initial Cr6+ concentration of 60 mg L−1, a temperature of 25 °C, a pH of 3, a TAM biomass of 0.05 g, and a contact time of 60 min at agitation conditions. Plackett–Burman design data shows the significance of each factor and how well the model fits the Cr6+ removal. The results of the germination experiment revealed that the highest significant increase in seed germination was achieved using a TAM level of 0.30 mg mL−1 with V. faba (88%) and 0.03 mg mL−1 with T. foenum-graecum (96.6%). Additionally, compared to the control group, TAM at a level of 0.037 mg mL−1 showed high root length enhancement on V. faba (184%) and T. foenum-graecum (188%). The results of the copepod O. nana feeding additive experiment found that the group fed on starch supplemented with TAM at a level of 0.3 mL L−1, compared to the control group that fed starch only, showed the highest increment in population growth (134.74%), fecundity (270.16%), and population composition of males (133.45%), adults (120.37%), and nauplius (203.18%). Moreover, compared to the control group, the copepod that fed starch supplemented with TAM levels achieved the highest Omega-9 content. In conclusion, it is shown that TAM is a feasible, efficient, and sustainable solution for biodegradable adsorbent for the Cr6+ from aqueous solution, enhances plant seed germination and root length, and is a novel feed additive for marine copepod O. nana, especially in marine invertebrate hatcheries.

The use of green technologies for processing lupin seeds (Lupinus angustifolius L.): Extraction of non-polar and polar compounds for concentrated-protein flour production

This study aimed to promote the valorization of lupin seeds by extracting both non-polar and polar fractions to produce a protein-rich flour suitable for food applications. Green extraction methods such as Supercritical Fluid Extraction (SFE) and SFE followed by gas-expanded liquid extraction with ethanol/CO2 mixtures were employed. SFE yielded lupin oil with extraction yields ranging from 2.27 ± 0.02 to 4.5 ± 0.2 %, significantly influenced by temperature (40 and 60 °C) and pressure (150–350 bar). SFE extracts exhibited higher tocopherol concentration, particularly α-tocopherol (116.7–296.9 µg/g oil) and γ-tocopherol (2006–4749 µg/g oil), compared to the Bligh and Dyer (B&D) method. The fatty acid profiles were similar, although they differed slightly in composition, with the extracts obtained by SFE having higher proportions of unsaturated fatty acids (UFA) and lower proportions of saturated fatty acids (SFA). Ethanol proportion positively correlated with extraction yield (r = 0.991), resulting in higher recovery of polar lipids (PL). However, increasing ethanol percentage decreased the phenolic compounds content and antioxidant activity assessed by DPPH radical scavenging method. SFE produced lupin flour with 36 % protein content, increased by 11 % post-extraction. Ethanolic extraction also increased protein concentration, albeit less pronounced (6.8–11 % increase post-sequential extraction). Essential amino acids consistently increased post-SFE, highlighting the potential of this sustainable method to yield protein-rich flour free of non-GRAS (Generally Recognized as Safe) solvents and containing compounds essential for human health. SDS-PAGE analysis showed consistent protein profiles across all extracted flours, while FTIR assessment revealed changes in the secondary structure of proteins induced by SFE and SFE followed by gas-expanded liquid extraction processes. These findings highlight the potential of this approach to enhance the nutritional and commercial value of lupin-based products while promoting sustainable food processing practices.

The experimental substantiation of the main parameters of the extraction of gaillardia herb (Gaillardia pulchella L.)

In the structure of the pharmaceutical market, the share of drugs based on the medicinal plant raw material (MPRM) is growing. Therefore, it is relevant to create a standardized domestic substance of natural origin – a liquid extract of gaillardia herb (Gaillardia pulchela L.) and develop new medicines based on it. Aim. To obtain a liquid extract by experimentally substantiating the main parameters of gaillardia herb extraction. Materials and methods. The study object was the raw material of gaillardia herb collected in the flowering phase at the Botanical Garden of the Poltava National Pedagogical University named after V. G. Korolenko (Poltava) in July and August 2022-2023, dried by the air-shade method and crushed by the rolling method. The crushed raw material was sifted through a sieve with a hole size of 10 mm. The millet was used for further research. The study of pharmaco-technological indicators was carried out according to the standard methods of the SPhU. Results and discussion. Since the complex of active substances of gaillardia herb was mainly represented by water-soluble BAS, it was necessary to choose a solvent that would remove this group of substances from the raw material as completely as possible. The experimental data obtained show that the ability to extract the BAS complex from gaillardia herb is preferred by purified water, which provides the maximum yield of extractive substances. The next stage of our research was to study the determination of the multiplicity of extraction, based on the determination of the maximum yield of extractive substances. Each of the extracts was selected fractionally with a step of DER 1:1 (drug extract ratio – the ratio of the starting material to the resulting extract). According to the data obtained, the amount of extractives passing during the extraction into the hood increases gradually up to 5 samples. Analyzing extracts from 6 to 10, it can be seen that the amount of extractives and a dry residue varies slightly; percolation with the extraction of more than 5 will lead to an increase in the consumption of the extractant and a decrease in the yield of active substances for the entire volume of the extractant. Conclusions. Based on the results of the studies conducted, the technological parameters of gaillardia herb have been determined (the volume mass – 0.453 ± 0.016 g/cm3; the bulk mass – 0.071 ± 0.001 g/cm3, the specific gravity – 1.214 ± 0.032 g/cm3, the water absorption coefficient – 1.68 ± 0.08). It has been experimentally proven that when extracting with purified water, the maximum yield of extractive substances is observed in the second volume, the yield of extractive substances is smooth, without sharp fluctuations in concentrations (in contrast to 40 and 70% ethanol). Therefore, the studies have determined an effective extractant for obtaining the extract, namely purified water. As a result of the pharmaco-technological tests conducted, the effective multiplicity of gaillardia herb extraction has been determined, which is equal to 5. The data will be taken into account when developing the technology of a liquid extract from gaillardia herb and choosing equipment for its production.

Discerning Emittable from Extractable Chemicals Identified in Consumer Products by Suspect Screening GCxGC-TOFMS.

Characterization of chemicals in household products is important for understanding this potential source of chemical exposure. Increasingly, suspect screening and nontargeted analysis techniques are used to characterize as many chemical signatures as possible. Solids such as household products are most conveniently prepared using solvent extraction, revealing what chemicals are contained within the product matrix but providing no information about the potential of those chemicals to leave the matrix and cause actual exposure. In this work, the profile and relative abundances of "extractable" chemical signatures found after solvent extraction are compared to those "emittable" to the headspace for 81 household products analyzed by two-dimensional gas chromatography time-of-flight mass spectrometry. This study retrospectively fuses data collected in separate efforts over 3.8 years and 13 analytical batches. Management of the data is made possible by recent developments in processing systems for complex data such as Highlight. Compounds were generically classified as aromatic heteroatom, aromatic hydrocarbon, glycol, hydrocarbon, long chain heteroatom, nonaromatic heteroatom, and unknown/unclassified. Class-based retention time and abundance trends were observed. Liquid extraction resulted in the greatest number of features and the highest relative abundances, while low temperature emission conditions produced the smallest number of features and lowest relative abundances.

Aqueous two-phase systems for environmentally friendlier separation of rare earth elements and transition metals: Applications and new molecular insights

Aqueous two-phase systems (ATPSs) have been proposed as an alternative liquid–liquid extraction technique applicable for the separation of economically valuable metals. However, gaps in knowledge and the need for a deeper understanding of the mechanisms involved in metal extraction still hinder the widespread adoption of these systems. In this study, ATPSs formed by TX-100 and electrolytes were employed to separate La, Pr, and Nd from Al and Fe. Use of an ATPS composed of TX-100, NH4SCN, and water, at pH 2.00, with a phase ratio of 1:5, resulted in total extraction of Al and Fe, although there was also considerable co-extraction of REEs. When a phase ratio of 1:2 was used for an ATPS composed of TX-100, (NH4)2SO4, and water, with NH4SCN as extractant, at pH 1.00, it was possible to separate Fe from the other metals, with significantly lower co-extraction of REEs and Al (%ELa = 4.05 %, %EPr = 6.19 %, %ENd = 4.87 %, %EFe = 98.61 %, %EAl = 2.54 %). The results of density functional theory (DFT) calculations correlated well with the experimental metal extraction data, demonstrating that the characteristics and solvation of the complexes formed in the ATPS played a fundamental role in metal partitioning. Measurements of the physical properties of the ATPS phases revealed variations in viscosity and interfacial tension values, which could assist in developing applications on a larger scale. The findings demonstrated that ATPSs could be used to separate REEs from transition metals, with potential applications in the recovery of REEs present in secondary sources.

New family of type V natural hydrophobic deep eutectic solvents based on thymol-acetamide/acetanilide: Characteristics, intermolecular interactions and applications in liquid–liquid extraction

To develop type V hydrophobic thymol-based Deep Eutectic Solvents (DESs) with low viscosity for liquid–liquid extraction, this work briefly reviews the thymol-based DESs reported in the literature, along with their various applications, and investigates the potential for DES formation between thymol and new materials. For this purpose, 39 combinations of thymol with different amino acids (5), acids (10), carbohydrates (13), amides (2), alkylammonium halides (4), and other compounds (5) were screened, resulting in the preparation of two new thymol-acetamide and thymol-acetanilide-based DESs. To identify the optimal molar ratios for DES formation, various combinations of thymol with acetamide and acetanilide were prepared, and their abilities to form stable liquids at room temperature, along with their thermal properties, were evaluated. Based on the solid–liquid equilibria (SLE) phase diagrams, it was found that stable liquids at ambient temperature were formed within the composition ranges of xACM = 0.29–0.40 (2.5:1–1.5:1) for THY:ACM and xACN = 0.29–0.33 (2.5:1 – 2:1) for THY:ACN. The mixtures with a molar ratio 2:1 were selected for further study, and their intermolecular interactions, characteristics, and applications in dye extraction were analyzed. FT-IR and NMR analyses were performed to investigate the structure and hydrogen bond formation between the DES components. Additionally, molecular dynamic (MD) simulations were conducted to examine the molecular structure and formation mechanisms of these DESs. The results indicated that hydrogen bonds are formed between the hydroxyl group (OH) of thymol and the carbonyl group (CO) of acetamide/acetanilide. Thermodynamic models, including regular solutions, NRTL, and Wilson, were employed to correlate the SLE phase diagrams of the studied mixtures, as determined by the DSC method. The physical properties of the prepared DESs, such as melting point, density, speed of sound, refractive index and viscosity, were measured at different temperatures. Due to their hydrophobic nature, the DESs demonstrated stability in aqueous solutions and thus can be used to extract various analytes from aqueous environments. The obtained solvents were applied for the extraction of methylene blue, methyl orange, and rhodamine B from aqueous solutions, as well as from real textile wastewater samples. Finally, to achieve optimal extraction conditions, the effects of various factors on extraction efficiency were investigated.

Di-[trioctyl-(8-phenyloctyl)-phosphonium] pamoate: synthesis and characterization of a novel, highly hydrophobic ionic liquid for the extraction of scandium, thorium and uranium.

We synthesized and characterized a novel, task-specific ionic liquid for metal extraction with considerably reduced leaching behavior compared to similar, phosphonium-based ionic liquids. The synthesis involves the design of the novel compound [TOPP]2[PAM] featuring both a highly hydrophobic cation and a functional anion. The characterization of the novel ionic liquid confirmed the formation of the desired structure and sufficient purity. The high viscosity of [TOPP]2[PAM] is responsible for the comparably high working temperature of 50°C. Extraction experiments demonstrated the suitability of [TOPP]2[PAM] for extracting Sc, Th and U from aqueous matrices, whereby extraction efficacies of 87.3% ± 9.1% (Sc), 95.8% ± 2.3% (Th) and 92.7% ± 0.3% (U) were achieved over 24h. Furthermore, Sc could be separated to a high degree via selective extraction from Th as well as from the rare earth elements Y, La, Ce, Nd, Eu, Ho and Lu. Th was separated from La, Ce, Nd, Eu, Ho and Lu at pH 1.00. During all extraction experiments, leaching into the aqueous extraction matrix peaked at only 0.134% ± 0.011% after 24h. The loading capacities for [TOPP]2[PAM] differed between the investigated metals, the highest values being achieved for U. After extraction, 82.7% ± 2.8% of the extracted Sc could be recovered from the IL using nitric acid (10%), but less of Th and U.

Detection of volatile organic compounds in soils (literature review)

Volatile organic compounds (VOC) are major environmental pollutants. Due to their high mobility, they penetrate into all environmental objects, pose an environmental threat and health risks. Getting into the soil, they deteriorate its quality. VOC content requires reliable control. There is presented a review of the literature, including methods of the US Environmental Protection Agency, and regulatory and methodological documents of the Russian Federation regulating methods of selection, storage, preparation and analysis of soil samples for VOC content. The dominant place among methods for monitoring for VOCs belongs to gas chromatography with various types of detectors. For multicomponent analysis of complex objects, gas chromatography with mass selective detection is used due to the wide capabilities provided by the mass detector. A universal mass spectrometry method used in analytical laboratories is electron impact ionization mass spectrometry. For research purposes, modern highly sensitive methods are used – mass spectrometry based on the proton transfer reaction PTR-MS, ion trap mass spectrometry PIT-MS, negative ion ionization mass spectrometry NI-PT-CIMS, time-of-flight mass spectrometry of the transfer reaction proton PTR-TOF-MS. The collection and storage of samples for VOC analysis requires compliance with regulations to prevent both loss of analytes and sample contamination. Sample preparation includes methods such as vacuum and azeotropic distillation, thermal desorption, liquid extraction, various options for static and dynamic headspace analysis.

Identification and quantification of the molecular species of bilirubin BDG, BMG and UCB by LC‒MS/MS in hyperbilirubinemic human serum.

Unconjugated bilirubin (UCB) is a byproduct of the heme group that indicates irregularities in the metabolism of several important biological molecules, such as hemoglobin. UCB is processed by hepatic UGT1A1, which catalyzes its conjugation to the metabolites bilirubin diglucuronide (BDG) and bilirubin monoglucuronide (BMG). The serum concentrations of BDG and BMG may indicate liver injury or dysfunction. The aim of this study was to standardize and validate a method for the identification and simultaneous quantification of BMG, BDG and UCB by LC‒MS/MS. Liquid‒liquid extraction allows the separation of UCB, BMG and BDG from the serum of healthy subjects or patients with liver injury. Detection and quantification were performed using an LC‒MS/MS method. Compound separation was achieved with a BEH-C18 column at 40°C. The mobile phase was prepared with 5 mM ammonium acetate (pH 6) and acetonitrile, and a flow gradient was applied. This is the first study to directly quantify BMG and UCB levels in human serum; no postcalculations or correction factors are needed. However, BDG quantification requires calculations and a correction factor. We identified the molecular species with ionic transitions m/z1+ 585.4 > 299.2 for UCB, 761.3 > 475.3 for BMG, 937.3 > 299.5 for BDG and mesobilirubin 589.4 > 301.3 (IS). The procedures used in this study allowed the simultaneous identification and quantification of the molecular species of bilirubin, BDG, BMG and UCB. Analysis of the serum levels in patients with hyperbilirubinemia revealed that patients with acute-on-chronic liver failure had elevated levels of these species.

A Microscopic Experimental Study on the Dominant Flow Channels of Water Flooding in Ultra-High Water Cut Reservoirs

The water drive reservoir in Shengli Oilfield has entered a stage of ultra-high water cut development, forming an advantageous flow channel for the water drive, resulting in the inefficient and ineffective circulation of injected water. Therefore, the distribution characteristics of water drive flow channels and their controlled residual oil in ultra-high water cut reservoirs are of great significance for treating water drive dominant flow channels and utilizing discontinuous residual oil. Through microscopic physical simulation of water flooding, color mixing recognition and image analysis technology were used to visualize the evolution characteristics of water flooding seepage channels and their changes during the control process. Research has shown that during the ultra-high water content period, the shrinkage of the water drive seepage channel forms a dominant seepage channel, forming a “seepage barrier” at the boundary of the dominant seepage channel, and dividing the affected area into the water drive dominant seepage zone and the seepage stagnation zone. The advantage of water flooding is that the oil displacement efficiency in the permeable zone is as high as 80.5%, and the remaining oil is highly dispersed. The water phase is almost a single-phase flow, revealing the reason for high water consumption in this stage. The remaining oil outside the affected area and within the stagnant flow zone accounts for 89.8% of the remaining oil, which has the potential to further improve oil recovery in the later stage of ultra-high water cut. For the first time, the redundancy index was proposed to quantitatively evaluate the control effect of liquid extraction and liquid flow direction on the dominant flow channels in water flooding. Experimental data showed that both liquid extraction and liquid flow direction can regulate the dominant flow channels in water flooding and improve oil recovery under certain conditions. Microscopic physical simulation experiments were conducted through the transformation of well network form in the later stage of ultra-high water content, which showed that the synergistic effect of liquid extraction and liquid flow direction can significantly improve the oil recovery effect, with an oil recovery rate of 68.02%, deepening the understanding of improving oil recovery rate in the later stage of ultra-high water content.

Increasing the selectivity of optical anion sensors with cationic extracting agents

ABSTRACT Anions play an important role in our life, from storing our genetic code on the polyanion DNA, to being the active ingredient in agricultural fertilisers and other industrial processes. Consequently, chemists have been designing systems that can sense anionic species through a variety of methods, such as unimolecular chromophores or sensor arrays. Nonetheless, most existing sensing approaches still have some drawbacks, particularly related to obtaining adequate selectivity and achieving sensing of anions in aqueous environments. In this manuscript, we report a liquid–liquid extraction (LLE)-based sensing approach that allows the conversion of non-selective optical anion sensors that only work in organic media, into selective sensing systems that allow detection of anions in water. We tested this approach on deprotonation-based anion sensors (alizarin, naphthol AS, 4-nitrophenol, BI-Lawsone, and chromophore 1) and hydrogen bonding-based anion sensors (1,2-diaminoanthraquinone and 4-nitro-1,2-phenylenediamine). In general, the deprotonation-based sensors could be converted from a non-selective sensor for basic anions (NCO¯, H2PO4¯, AcO¯ and F¯) to a selective sensing system for NCO¯ with the aid of carefully chosen tetraalkylammonium salts as extracting agents. On the other hand, the hydrogen-bonding based sensors could be converted to a selective sensing system for the hydrophobic anion ClO4¯ using similar tetraalkylammonium salts.

Recovery of bioactive compounds from pineapple waste through high-pressure technologies

This study aimed to obtain bioactive compounds from the residue from pineapple (Ananas comosus L. Merril) juice processing, using supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE). The SFE were performed using ethanol as a co-solvent and evaluating different pressure, temperature, and co-solvent percentage. For the PLE, temperature and ethanol percentage were assessed. The best extraction conditions for SFE were 20 MPa, 60 °C, and 15 % ethanol, while for PLE they were obtained at 10 MPa, 100 °C with 50 % and 75 % ethanol. Both methods presented a higher concentration of bioactives than other recognized vegetable waste sources. However, it was observed that PLE showed a higher overall extract yield, phenolic compounds, flavonoids, carotenoids, and antioxidant activity. The main phenolic compounds identified were caffeic acid and ferulic acid. Therefore, pineapple residue is a potential source of bioactive compounds, and the pressurized liquid extraction technique proved more efficient for their recovery.

Comb-grafted poly(vinyl phosphate)-based molybdovanadate heteropoly acid for efficient deep oxidative desulfurization using ionic liquid extractants under mild conditions

The development of simple and efficient desulfurization catalysts has garnered increasing attention in the field of desulfurization. In this study, comb-grafted polyethylene phosphomolybdenum-vanadium heteropoly acid catalysts (P-VPA-MomVn) were synthesized via the bulk polymerization method. The structure and morphology of the catalysts were investigated by FTIR, GPC, 1H NMR, XRD, XPS and SEM. By incorporating ionic liquid as an extractant, the P-VPA-Mo10V2 demonstrates high activity in oxidative desulfurization, removing all DBT from the model oil with a low O/S molar ratio under mild conditions. It is noteworthy that when the reaction temperature is 30 °C, the O/S molar ratio is 3, and the reaction time is 60 min, the catalyst exhibits excellent recycling lifetime of 10 cycles without a significant decline in activity. The incorporation of the ionic liquid further enhances its extraction efficiency, indicating that the catalyst not only possesses a stable structure but also holds strong prospects for industrial application.

Araçaúna (Psidium myrtoides) flour: Sequential extraction with supercritical carbon dioxide and pressurized fluids

Araçaúna (Psidium myrtoides) is a native fruit from the Brazilian Atlantic Forest. It was studied for the proximate composition of its flour and sequential extraction using supercritical fluid extraction (SFE) in the first stage with CO2 and pressurized liquid extraction (PLE) with ethanol and water in the second and third stages, respectively, at 50°C and 60°C. The proximate analysis revealed essential information about the flour regarding the content of protein, carbohydrates, lipid, ash and moisture. The sequential extraction at 60°C resulted in high yields (42.22 %). The first stage using SFE captured the volatile fraction, notably 1,4-diethylbenzene, which corresponds to 53.70 % of the total volatile compounds identified in the araçaúna. Comparing the second and third stages, the third stage with water at 50°C produced the highest levels of phenolic compounds (33.06±2.26 mg GAE/g extract), total monomeric anthocyanins (3.91±2.10 mg C3G/g extract), antioxidant activity by ORAC (415.13±13.66 µmol TE/g extract) and FRAP (747.16±18.49 µmol TE/g extract), and cyanidin-3-glucoside as the predominant compound (4.83 % w/w).

Antibiotics in honey: a comprehensive review on occurrence and analytical methodologies.

Honey is a food of great nutritional importance and has always been used for human consumption. The production of honey and other beekeeping products depends on the proper functioning of this extremely important sector, as it has a direct impact on other sectors such as agriculture. The decline in bee colony numbers has been linked, among other factors, to bacterial diseases affecting bees, including American and European foulbrood, and Nosema spp. disease. In this matter, prophylactic or therapeutic use of veterinary drugs in apiculture is common but can lead to their accumulation in bees and in honey. Consumption of contaminated honey can have adverse effects such as allergic or hypersensitivity reactions, carcinogenicity, reproductive effects, and teratogenicity. Commission Regulation (EU) N ⍛ 37/2010 sets MRLs for antibiotics in various foods, but these limits are not set for api-products. The lack of harmonized rules has led some countries to set recommended concentrations and minimum performance limits. Nonetheless, to achieve this goal, development of accurate and precise analytical methodologies is crucial. In recent years, the analysis of antibiotics in honey has led to the development of methods in an extensive range of families, including aminoglycosides, amphenicols, lincosamides, macrolides, nitroimidazoles, quinolones, sulfonamides, tetracyclines and nitrofurans. This review work entails an in-depth exploration of occurrence studies, extraction methodologies, and analytical techniques for the determination of antibiotics in apiculture products. It was found that the most used extraction methods include solid-phase extraction, dispersed solid or liquid phase extraction and QuEChERS. Due to the complexity of the honey matrix, samples are often diluted or acidified using McIlvaine buffer, H 2O, MeOH, acidified ACN and TCA solution. This is usually followed by a purification step using SPE cartridges or PSA. Golden analytical methodologies include high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer (MS/MS) with Orbitrap or Q-ToF detectors.