Maximum Extraction Research Articles

Extraction of Pithecellobium clypearia Benth polysaccharides by dual-frequency ultrasound-assisted extraction: Structural characterization, antioxidant, hypoglycemic and anti-hyperlipidemic activities

In this research, the extraction process of polysaccharides from Pithecellobium clypearia Benth (PCBPs) was optimized using dual-frequency ultrasound-assisted extraction (DUAE). The biological activities of PCBPs were investigated by in vitro antioxidant, hypoglycemic, and anti-hyperlipidemic assay. High-performance anion-exchange chromatography, high-performance gel permeation chromatography, SEM, UV–Vis spectroscopy, and FT-IR spectra were used to analyze the monosaccharide composition, molecular weight, microscopic morphology, and characteristic structure of PCBPs. The results showed that the maximum extraction rate of PCBPs was 9.90 ± 0.16% when the ultrasonic time was 8 min, the liquid-to-material ratio was 32 mL/g, and the ultrasonic power was 510 W. The PCBPs also possessed excellent in vitro antioxidant, hypoglycemic, and anti-hyperlipidemic activities. In addition, the average molecular weight of PCBPs was 15.07 kDa. PCBPs consisted of rhamnose, arabinose, galactose, glucose, xylose, mannose, and glucuronic acid, with the molar ratios of 11.07%, 18.54%, 48.17%, 10.44%, 4.62%, 4.96%, and 2.20%, respectively. Moreover, the results of SEM showed that PCBPs mainly showed a fine spherical mesh structure. The above studies provided a valuable theoretical basis for the subsequent in-depth study of PCBPs.

A methylene blue assay for the quantification of fucoidan – A specific application for seaweed extracts

Fucoidan is a fucose-rich sulfated polysaccharide found mainly in brown seaweeds. Fucoidan has recently gained much attention due to its bioactive and medicinal properties, hence its high potential to be utilized in the pharmaceutical industry. Therefore, an accurate, reliable, and simple method for the specific determination of fucoidan would be a useful tool when looking to recover this valuable polysaccharide. This research focused on developing an assay utilizing the thiazine dye, methylene blue, for the quantification of fucoidan, with a specific application for fucoidan found in algal extracts. Fucoidan could be specifically determined at pH 1, to maximum concentrations of 4 g L-1 in solution without the interference of alginate and other seaweed extract contaminants. At pH 7 and 11, quantification of fucoidan led to interference from alginate and gallic acid. A conversion factor of 1.8 allowed the quantification of fucoidan from Ecklonia maxima extracts using a commercial standard from Fucus vesiculosis. An Ecklonia maxima extract was found to contain 5.47 ± 0.061 g L-1 of fucoidan. Measuring the fucoidan and L-fucose concentration in crude seaweed extract through the methylene blue assay and modified Dische and Shettles J Biol Chem 175:595–603, (1948) method, respectively, confirmed the accuracy and specificity of the method. The limit of quantification of the methylene blue assay at pH 1 was 0.62 g L-1 of fucoidan.

Discharge variations of qanat near an ephemeral stream

Ephemeral streams are the most important sources of groundwater recharge in arid and semi-arid regions of the world. To extract this replenishable water, most of the time, qanats are constructed parallel to the ephemeral streams. Analytical modeling of a stream-qanat system can provide an effective tool for managing such a system in a timely fashion and, thus, is commonly applied in the hydrological communities. However, the available analytical solutions of discharge variation of qanat only consider the distributed recharge from rainfall and cannot be used to investigate the effects of geometric parameters of stream and hydraulic parameters of aquifer on the discharge of qanat near an ephemeral stream. Thus, the goal of this work is to obtain a semi-analytical solution of qanat discharge due to recharge from an ephemeral stream of an arbitrary shape in a three-dimensional anisotropic homogeneous unconfined aquifer. The solution is obtained via Laplace and Fourier transformations along with the principle of superposition. The results of this study are presented in the form of qanat discharge-time curves. The influences of the qanat length, shape, and recharge distribution along the ephemeral stream are explored in great detail. The effects of the hydraulic parameters of the aquifer on the discharge of qanat are also investigated. The results of this study can be used to predict the discharge of qanat due to recharge from an ephemeral stream, to calculate the optimum length of a qanat for maximum extraction of the replenished water, to estimate the adequate recharge from the ephemeral stream and the hydraulic parameters of aquifer using the discharge data of qanat, among other applications.

The fractional extraction for sustainable recovery of rare earth and thorium in radioactive waste with oxoacetate functionalized ionic liquid

Rare earth (RE) are critical elements in many technologies, their clean production has attracted widespread attentions. To develop clean separation technology for RE, a novel oxoacetate ionic liquid (IL) extractant was developed to recovery RE elements and Thorium (Th) in the radioactive waste residue from ion-absorbed RE separation industry. The IL [N-methyl-N,N-dioctyloctan-1-aminium][2-(bis(2-ethylhexyl)amino)-2-oxoacetate] ([N1888][DEAO]) had good selectivity to RE and Th, which helps to remove radioactive Th and recover RE from waste residue leachate. RE and Th could be effectively separated with 0.02 mol/L [N1888][DEAO]. Maximum extraction capacity of Th reached 1.02 g/L, which could meet the needs of Th removal in the waste residue. A combination of saturated NaC2O4 solution and NaOH solution was used for the stripping of Th. After five cycles, the extraction efficiency of Th remained above 90 %. After four-stage extraction with [N1888][DEAO] and three-stage scrubbing, a RE solution with Th content less than 0.6 mg/L was obtained. It is fully achieved that there is no excess wastewater and waste salt in the fractional process. The RE elements in the waste residue can be effectively recycled, also the collection of the radioactive element Th can be realized.

Polyphenols from Sage Leaves (Salvia officinalis L.): Environmentally Friendly Extraction under High Hydrostatic Pressure and Application as a Corrosion Inhibitor for Tinplate

Due to the diversity of organic molecular structures present in sage extract, sage extract is a promising potential source of a cheap and effective biodegradable green corrosion inhibitor for tinplate in 3% NaCl solution, which was evaluated in this study. HHP proved to be a new and emerging technology for the useful extraction of polyphenols from sage as a functional ingredient from natural sources. Analysis of variance among all tested independent factors (ethanol concentration, HHP parameters and temperature) revealed significant differences (p < 0.05) in total polyphenol content as well as for rosmarinic acid as the major phenolic compound in sage extract, while extraction time had no effect (p ˃ 0.05). The optimum HHP conditions (600 MPa, 30% ethanol, 60 °C and 5 min) gave a maximum extraction yield of total polyphenols of 3811.84 mg/100 g. Sage-leaf extracts were found to be a mixture of phenolic acids, namely rosmarinic and salvianolic acid K, epicatechin and luteolin-7-O-glucuronide glycoside. The corrosion results show that the sage extract at a concentration of 0.6 g/L in 3% NaCl is an effective corrosion inhibitor (93%), forming a passivation layer of sage extract consisting of organic compounds such as polyphenols on the surface of tinplate.

Selective Recovery of Gold from E-Waste Recycling Plants’ Waste Fractions: Waste-to-Resource Transition

Electronic waste grows globally at a rate of 5% annually, which makes electronic waste recycling (WEEE recycling) an urgent task aimed at achieving (i) environmental protection and (ii) the preservation of mineral resources through the re-introduction of strategic metals into the market. As it turns out, WEEE recycling produces further waste, called WEEE secondary waste, which still contains valuable metals such as gold, silver, and copper. This study assessed the economic viability of recovering these metals and identified the most promising targets and approaches. WEEE secondary waste produced at a plant in southern Europe was sampled and examined for this purpose. The study methods included an ANOVA (analysis of variance) and an OCCP (orthogonal central composition plan). Over 90% gold, silver, and copper extraction was achieved with hydrochloric acid leaching in sodium hypochlorite with sodium chlorite as an oxidizing agent at 60 °C. The significance of the variation in the response for each factor, calculated using the Yates algorithm, demonstrates that by excluding sodium chloride and optimizing the doses of hydrochloric acid and sodium hypochlorite, gold can be selectively recovered through the leaching process. The scenario of HCl (2.5M)/NaClO (5%) leaching results in the maximum extraction effect of Au (91.6%) at the lowest concentrations of Ag and Cu (37–44%).

Synthesis of polyethylene glycol-grafted magnetic nanoparticles for the fast and efficient extraction of anabolic substances from human urine

Anabolic steroids and β-agonists are commonly prohibited substances found in doping control studies; therefore, the determination of anabolic substances in biological samples is crucial. To analyze the anabolic compounds in urine, an adsorbent, polyethylene glycol (PEG)-grafted magnetic nanoparticle material (Fe3O4@SiO2-PEG), with low toxicity and strong biocompatibility was prepared in this investigation. Compared to those of Fe3O4 and Fe3O4@SiO2, the grafted PEG chains (approximately 5.4 wt.%) on the magnetic nanoparticles improved the extraction efficiencies by factors of 3.9–17.0 and 2.5–2.9, respectively, likely due to the electrostatic attraction and hydrogen bonding. To achieve maximum extraction efficiency, several extraction parameters were optimized, including the kind and volume of desorption solvent, pH, and the extraction and desorption time. The standard curves were linear within the range of 0.5–20 μg/L for methyltestosterone and trenbolone, and 0.02–5 μg/L for clenbuterol. The limits of detection for the three drugs were 0.01–0.12 μg/L. The limits of quantification were 0.02–0.40 μg/L. The levels of precision of the optimized method were assessed based on the respective intra- and inter-day and batch-to-batch relative standard deviations in the ranges of 3.2–5.2 % (n = 5), 5.9–11.3 % (n = 4), and 6.7–9.2 % (n = 3). The Fe3O4@SiO2-PEG nanoparticles could exclude urine matrix interferences (matrix effect of 91.8–98.1 %) and achieve satisfactory recoveries (75.5–116.1 %), affording sensitive and accurate determination of trace anabolic substances in urine.

The development and structural validity testing of the Person-centred Practice Inventory-Care (PCPI-C).

Person-centred healthcare focuses on placing the beliefs and values of service users at the centre of decision-making and creating the context for practitioners to do this effectively. Measuring the outcomes arising from person-centred practices is complex and challenging and often adopts multiple perspectives and approaches. Few measurement frameworks are grounded in an explicit person-centred theoretical framework. In the study reported in this paper, the aim was to develop a valid and reliable instrument to measure the experience of person-centred care by service users (patients)-The Person-centred Practice Inventory-Care (PCPI-C). Based on the 'person-centred processes' construct of an established Person-centred Practice Framework (PCPF), a service user instrument was developed to complement existing instruments informed by the same theoretical framework-the PCPF. An exploratory sequential mixed methods design was used to construct and test the instrument, working with international partners and service users in Scotland, Northern Ireland, Australia and Austria. A three-phase approach was adopted to the development and testing of the PCPI-C: Phase 1 -Item Selection: following an iterative process a list of 20 items were agreed upon by the research team for use in phase 2 of the project; Phase 2 -Instrument Development and Refinement: Development of the PCPI-C was undertaken through two stages. Stage 1 involved three sequential rounds of data collection using focus groups in Scotland, Australia and Northern Ireland; Stage 2 involved distributing the instrument to members of a global community of practice for person-centred practice for review and feedback, as well as refinement and translation through one: one interviews in Austria. Phase 3: Testing Structural Validity of the PCPI-C: A sample of 452 participants participated in this phase of the study. Service users participating in existing cancer research in the UK, Malta, Poland and Portugal, as well as care homes research in Austria completed the draft PCPI-C. Data were collected over a 14month period (January 2021-March 2022). Descriptive and measures of dispersion statistics were generated for all items to help inform subsequent analysis. Confirmatory factor analysis was conducted using maximum likelihood robust extraction testing of the 5-factor model of the PCPI-C. The testing of the PCPI-C resulted in a final 18 item instrument. The results demonstrate that the PCPI-C is a psychometrically sound instrument, supporting a five-factor model that examines the service user's perspective of what constitutes person-centred care. This new instrument is generic in nature and so can be used to evaluate how person-centredness is perceived by service users in different healthcare contexts and at different levels of an organisation. Thus, it brings a service user perspective to an organisation-wide evaluation framework.

Production of Anthocyanin-Rich Red Rose Petal Extract by Enzymatic Maceration

The use of enzymes to hydrolyze the plant cell matrix is a method known for extracting bioactive substances. The current work used this strategy to produce a rose petal extract rich in anthocyanins that is stable in the presence of marine polysaccharides and has a high antioxidant activity. The process evaluation was carried out sequentially, initially comparing water, ethanol, and their mixtures to anthocyanins extracted in the presence or absence of enzymes. Then, a multi-objective desirability function optimized experimental conditions such as solvent and enzyme concentrations. This study is the first report describing the use of a statistical tool, the central composite rotatable design (CCRD), to optimize anthocyanin extraction from rose petals. This method obtained a maximum extraction of 9.99 mg/g of phenols. The stability of the rose petal extract when using marine polysaccharides retained 60% of the anthocyanins over 28 days without deterioration when protected from sunlight but was practically degraded upon exposure to sunlight. The rose petal extract demonstrated a very high antioxidant capacity of 3.19 μg/mL, close to the literature data for citrus compounds, known to be high in antioxidant compounds for cosmetic food purposes.

Enhancing Cutin Extraction Efficiency from Industrially Derived Tomato Processing Residues by High-Pressure Homogenization.

This study primarily aimed to enhance the extraction of cutin from industrial tomato peel residues. Initially, the conventional extraction process was optimized using response surface methodology (RSM). Subsequently, high-pressure homogenization (HPH) was introduced to improve extraction efficiency and sustainability. The optimization process focused on determining the optimal conditions for conventional extraction via chemical hydrolysis, including temperature (100-130 °C), time (15-120 min), and NaOH concentration (1-3%). The optimized conditions, determined as 130 °C, 120 min, and 3% NaOH solution, yielded a maximum cutin extraction of 32.5%. Furthermore, the results indicated that applying HPH pre-treatment to tomato peels before alkaline hydrolysis significantly increased the cutin extraction yield, reaching 46.1%. This represents an approximately 42% increase compared to the conventional process. Importantly, HPH pre-treatment enabled cutin extraction under milder conditions using a 2% NaOH solution, reducing NaOH usage by 33%, while still achieving a substantial cutin yield of 45.6%. FT-IR analysis confirmed that cutin obtained via both conventional and HPH-assisted extraction exhibited similar chemical structures, indicating that the main chemical groups and structure of cutin remained unaltered by HPH treatment. Furthermore, cutin extracts from both conventional and HPH-assisted extraction demonstrated thermal stability up to approximately 200 °C, with less than 5% weight loss according to TGA analysis. These findings underscore the potential of HPH technology to significantly enhance cutin extraction yield from tomato peel residues while utilizing milder chemical hydrolysis conditions, thereby promoting a more sustainable and efficient cutin extraction process.

The optimisation of caffeic acid reactive extraction by trioctylphosphine oxide using response surface methodology

ABSTRACT Caffeic acid is a valuable product due to its wide-ranging utilities. Currently, caffeic acid can be produced via fermentation process using native or engineered microorganisms. The reactive extraction is a prominent technique that is used for the recovery of carboxylic acids. In this work, caffeic acid was recovered by an organophosphate (trioctylphosphine oxide) from its aqueous solution in the presence of different kinds of solvents namely 1-butanol, ethyl propionate, and ethyl methyl ketone. The values of reactive extraction parameters were optimised by Box–Behnken design. 98.19% The maximum extraction efficiency was obtained as 98.19% at the optimum conditions of 0.003 mol kg−1 caffeic acid concentration, 50% (v/v) trioctylphosphine oxide quantity, and 306.2 K in the presence of 1-butanol as the solvent. Our study is the first ever to examine the reactive extraction of caffeic acid, and therefore very important in modern scientific disciplines.

Reducing operational risks during suspensions separation in rare metals technology

The work presents the results of studies of the solid-liquid separation processes of different mineralogical and granulometric compositions, different viscosity and concentrations of uranium, zirconium, nitric acid, soda, sodium nitrate. It has been shown that the process of industrial filtration is impossible for finely dispersed phases due to the low separation rate. Requirements for the purity of technological solutions of uranium and zirconium for the extraction process are limited by the technological ability of the filter fabric to retain the smallest particles, including chemical compounds with a particle size of 1–5 μm. The control filtration process is only possible under pressure, for which a new disk press filter was created, which reduced the concentration of the solid phase in the filtrate to 0.06 g/L. For difficult-to-filter suspensions, a screw centrifuge was developed, which ensured minimum sediment moisture after separating the finely dispersed phase from a solution of soda and sodium silicate and created conditions for maximum extraction of zirconium and hafnium from the solid phase. The separation of water-soluble sodium silicate ensured the stability of the process of extraction separation of zirconium and hafnium and made it possible to isolate silicon oxide.

A Novel Spatiotemporal Periodic Polynomial Model for Predicting Road Traffic Speed

Accurate and fast traffic prediction is the data-based foundation for achieving traffic control and management, and the accuracy of prediction results will directly affect the effectiveness of traffic control and management. This paper proposes a new spatiotemporal periodic polynomial model for road traffic, which integrates the temporal, spatial, and periodic features of speed time series and can effectively handle the nonlinear mapping relationship from input to output. In terms of the model, we establish a road traffic speed prediction model based on polynomial regression. In terms of spatial feature extraction methods, we introduce a maximum mutual information coefficient spatial feature extraction method. In terms of periodic feature extraction methods, we introduce a periodic trend modeling method into the prediction of speed time series, and effective fusion is carried out. Four strategies are evaluated based on the Guangzhou road speed dataset: a univariate polynomial model, a spatiotemporal polynomial model, a periodic polynomial model, and a spatiotemporal periodic polynomial model. The test results show that the three methods proposed in this article can effectively improve prediction accuracy. Comparing the spatiotemporal periodic polynomial model with multiple machine learning models and deep learning models, the prediction accuracy is improved by 5.94% compared to the best feedforward neural network. The research in this article can effectively deal with the temporal, spatial, periodic, and nonlinear characteristics of speed prediction, and to a certain extent, improve the accuracy of speed prediction.

Development and psychometric evaluation of "Caring Ability of Mother with Preterm Infant Scale" (CAMPIS): a sequential exploratory mixed-method study.

Caring ability is one of the most important indicators regarding care outcomes. A valid and reliable scale for the evaluation of caring ability in mothers with preterm infants is lacking. The present study was conducted with the aim of designing and psychometric evaluation of the tool for assessing caring ability in mothers with preterm infants. A mixed-method exploratory design was conducted from 2021 to 2023. First the concept of caring ability of mothers with preterm infants was clarified using literature review and comparative content analysis, and a pool of items was created. Then, in the quantitative study, the psychometric properties of the scale were evaluated using validity and reliability tests. A maximum likelihood extraction with promax rotation was performed on 401 mothers with the mean age of 31.67 ± 6.14years to assess the construct validity. Initial caring ability of mother with preterm infant scale (CAMPIS) was developed with 64 items by findings of the literature review, comparative content analysis, and other related questionnaire items, on a 5-point Likert scale to be psychometrically evaluated. Face, content, and construct validity, as well as reliability, were measured to evaluate the psychometric properties of CAMPIS. So, the initial survey yielded 201 valid responses. The three components: 'cognitive ability'; knowledge and skills abilities'; and 'psychological ability'; explained 47.44% of the total observed variance for CAMPIS with 21 items. A subsequent survey garnered 200 valid responses. The confirmatory factor analysis results indicated: χ2/df = 1.972, comparative fit index (CFI) = 0.933, and incremental fit index (IFI) = 0.933. These results demonstrate good structural, convergent, discriminant validity and reliability. OMEGA, average inter-item correlation (AIC), intraclass correlation coefficients (ICC) for the entire scale were at 0.900, 0.27 and 0.91 respectively. Based on the results of the psychometric evaluation of CAMPIS, it was found that the concept of caring ability in the Iranian mothers with preterm infants is a multi-dimensional concept, which mainly focuses on cognitive ability, technical ability, and psychological ability. The designed scale has acceptable validity and reliability characteristics that can be used in future studies to assess this concept in the mothers of preterm infants.

Ultrasonic-Assisted Extraction of Dictyophora rubrovolvata Volva Proteins: Process Optimization, Structural Characterization, Intermolecular Forces, and Functional Properties.

Dictyophora rubrovolvata volva, an agricultural by-product, is often directly discarded resulting in environmental pollution and waste of the proteins' resources. In this study, D. rubrovolvata volva proteins (DRVPs) were recovered using the ultrasound-assisted extraction (UAE) method. Based on one-way tests, orthogonal tests were conducted to identify the effects of the material-liquid ratio, pH, extraction time, and ultrasonic power on the extraction rate of DRVPs. Moreover, the impact of UAE on the physicochemical properties, structure characteristics, intermolecular forces, and functional attributes of DRVPs were also examined. The maximum protein extraction rate was achieved at 43.34% under the best extraction conditions of UAE (1:20 g/mL, pH 11, 25 min, and 550 W). UAE significantly altered proteins' morphology and molecular size compared to the conventional alkaline method. Furthermore, while UAE did not affect the primary structure, it dramatically changed the secondary and tertiary structure of DRVPs. Approximately 13.42% of the compact secondary structures (α-helices and β-sheets) underwent a transition to looser structures (β-turns and random coils), resulting in the exposure of hydrophobic groups previously concealed within the molecule's core. In addition, the driving forces maintaining and stabilizing the sonicated protein aggregates mainly involved hydrophobic forces, disulfide bonding, and hydrogen bonding interactions. Under specific pH and temperature conditions, the water holding capacity, oil holding capacity, foaming capacity and stability, emulsion activity, and stability of UAE increased significantly from 2.01 g/g to 2.52 g/g, 3.90 g/g to 5.53 g/g, 92.56% to 111.90%, 58.97% to 89.36%, 13.85% to 15.37%, and 100.22% to 136.53%, respectively, compared to conventional alkali extraction. The findings contributed to a new approach for the high-value utilization of agricultural waste from D. rubrovolvata.

Design of novel differential power processing scheme for small-scale PV array application operating under partial shading conditions: modelling and experimental validation

In this study, an innovative approach known as Series and Parallel Differential Power Processing (SP-DPP) converters has been introduced and applied to a small-scale 2 × 2 PV array configuration. Unlike conventional methods, this approach employs Bidirectional Ćuk DC-DC Converters (BCC) in lieu of bypass diodes within serially connected PV modules, facilitating precise adjustment of module currents. Additionally, the Differential Power Processing (DPP) mechanism, utilising an Inverted-Buck Converter (IBC) topology, replaces traditional blocking diodes across parallel string connections. The paper develops mathematical models for these converters based on their transfer functions in the Continuous Conduction Mode (CCM), establishing new design criteria for SP-DPP systems. This approach ensures a well-behaved transient response and mitigates non-minimum phase response effects. Empirical testing demonstrates the efficacy of the proposed system under various static and dynamic partial shading conditions (PSCs). Furthermore, a model-based control strategy employing P + I controllers are formulated and experimentally validated to optimise the operating conditions of PV modules, enabling them to operate at their Maximum Power Points (MPPs) in varying lighting conditions. Through simulation and experimental results, the study affirms a substantial increase in the total output power of the SP-DPP system (approximately 37–41 %) compared to conventional Tied-Crossties (TCT) array configuration relying solely on bypass and blocking diodes under various static shading conditions, such as Short-Narrow (SN), Short-Wide (SW), Long-Narrow (LN) and Long-Wide (LW). Ultimately, this research highlights the novelty of the proposed SP-DPP scheme over other existing DPP schemes in the literature, in terms of maximum power extraction, cost and complexity under various lighting conditions. This research extends to explore the potential economic viability and global implications of large-scale DPP system implementation.

Three-component deep eutectic solvent for revered-phase air-assisted liquid–liquid microextraction for the determination of furanic compounds in transformer oil by HPLC-UV

In this work, a revered-phase air-assisted liquid–liquid microextraction approach based on three-component deep eutectic solvent for pretreatment of petroleum oils was developed. The approach was utilized for the determination of furanic compounds in aged transformer oil by high-performance liquid chromatography with UV detection. The procedure assumed multiple aspiration of oil sample and deep eutectic solvent into a syringe and injection of the extraction mixture into an Eppendorf tube (11 instant extraction cycles). This process resulted in the formation of a cloudy solution, attributed to the dispersion of extraction solvent droplets into the oil sample. After centrifugation the obtained extract phase was introduced into a chromatographic system without additional purification and dilution. To establish the optimal microextraction procedure conditions, key parameters such as the extraction solvent composition, phase ratio and the number of extraction cycles were investigated. Cheap and available low viscosity deep eutectic solvent based on choline chloride, acetic acid and water provided the highest extraction recovery values (from 85 to 96 %). It was found, that acetic acid as precursor of extraction solvent acted key-role for maximum extraction recovery for all analytes. The phenomenon of the influence of hydroxyl groups in the structure of analytes on the extraction efficiency was revealed. Under optimal condition, the limits of detection were in the range from 3 to 6 μg L−1.

A micro-extraction/derivatization method for RP-HPLC-FLD analysis of amino acids in wild boar meat

Methods that are easy to use, spend small amounts of reagents, and have minimal human interference are precious tools in different areas. Sus scrofa is the wild animal most used in human diet, however, the knowledge about its protein fraction is still scarce. In this work, a method for 22 amino acids quantification was optimized and applied to the analysis of meat from animals of different ages and genders. The optimization of acid and basic hydrolyses reveal an ideal mass between 75 and 100 mg, with 3 mL of hydrolysis reagent, and 22 h for a maximum extraction of tryptophan. The hydrolysates were automatically derivatized using few µL, and the compounds were analyzed by reversed phase - high performance liquid chromatography with fluorescence detection. For comparison purposes, total protein was assessed, using the Kjeldahl method. The method showed high precision and accuracy, as well as very low limits of detection and quantification, with good potential to be applied to other animal meats. Significant differences were found between the amino acid profile of different animals (e.g. aspartic acid and taurine contents were slightly higher in juveniles than in adults).

Comprehensive Assessment of Polysaccharides Extracted from Squash by Subcritical Water under Different Conditions.

The effects of subcritical water microenvironment on the physiochemical properties, antioxidant activity and in vitro digestion of polysaccharides (SWESPs) from squash were investigated. After single-factor experiments, twenty samples were successfully prepared at different extraction temperatures (110, 130, 150, 170 and 190 °C) and extraction times (4, 8, 12 and 16 min). Under a low temperature environment, the whole process was mainly based on the extraction of SWESP. At this time, the color of SWESP was white or light gray and the molecular mass was high. When the temperature was 150 °C, since the extraction and degradation of SWESP reached equilibrium, the maximum extraction rate (18.67%) was reached at 150 °C (12 min). Compared with traditional methods, the yield of squash SWESP extracted by subcritical water was 3-4 times higher and less time consuming. Under high temperature conditions, SWESPs were degraded and their antioxidant capacity and viscosity were reduced. Meanwhile, Maillard and caramelization reactions turned the SWESPs yellow-brown and produced harmful substances. In addition, different SWESPs had different effects on in vitro digestion. In brief, SWESPs prepared under different conditions have different structures and physicochemical properties, allowing the obtainment of the required polysaccharide. Our results show that squash polysaccharides prepared in different subcritical water states had good development potential and application in the food industry.

Efficient extraction of gold from model and real leach solutions using guanidinium ionic liquids

With the rapid development of modern industry, it is necessary to effectively recycle precious metals such as gold and palladium from e-waste. IL (ionic liquid) is an efficient extractant with high boiling points, non-flammability, and high thermal stability. The properties of IL can be improved by modifying the n-substituted groups of their cations, enhancing the separation efficiency of noble metals. Thus, two guanidinium ILs, with the substituents of -R and -OR, were synthesized to extract Au(III) from a HCl medium. These ILs exhibited excellent extraction properties, including high selectivities, rapid kinetics, and significant extraction capacities. The maximum extraction capacities of Au(III) by [diMTMG][Tf2N] and [diPTMG][Tf2N] were 519.4 mg/g and 427.9 mg/g, respectively, achieving rapid extraction equilibrium within 30 s. The introduction of O-containing functional atoms enhanced extraction capacity and selectivity. The extraction selectivity of the two ILs for real e-waste leachate was investigated in pure-ILs and diluent-involved systems, respectively. The results indicated that [diPTMG][Tf2N] showed excellent extraction of Au(III) from e-waste in both conditions.