Selected Extraction Conditions Research Articles

Hydrometallurgical recovery of Zn(II) and Mn(II) from alkaline batteries waste employing aqueous two-phase system

Abstract In this study, a greener method for the recovery of zinc and manganese from alkaline batteries waste was developed using Aqueous Two-Phase System (ATPS). ATPS is a liquid-liquid extraction technique. Zn(II) and Mn(II) were extracted using the diluted liquor from samples of spent alkaline batteries, and the experimental conditions were evaluated considering the effects of the following parameters: (i) nature and concentration of the extractants (1-(2-pyridyl-azo)-2-naphthol (PAN), (bis-4-trimethylpentyl) phosphinic acid (Cyanex 272), diphenylthiocarbazone (dithizone, C13H12N4S) and bis-(2-ethylhexyl) phosphoric acid (D2EHPA)); (ii) pH (3.00, 6.00 and 11.0), (iii) ATPS-forming electrolytes (Na2SO4, C6H5Na3O7 or C4H4Na2O6); (iv) ATPS-forming polymers (L35 and L64); and (v) tie-line length (TLL) and mass ratio between top and bottom phases (mTP/mBP). The recovery efficiency was evaluated using the extraction percentage (%E) and separation factor ( S Zn / M n ) between Zn(II) and Mn(II). The best conditions for selective extraction of the metal ions were achieved using an ATPS composed by L64 + Na2SO4 + H2O at pH = 3.00, TLL = 41.83% w/w and mTP/mBP = 1 using dithizone as the extracting agent and leach liquor with dilution factor equal to 10. This resulted in a value for separation factor of S Zn / M n = 1.2 × 106, in one extraction stage.

Optimized Quantitative Method for Determining Isoflavones and Equol in Bovine Digestive Fluids and Feces

ABSTRACTMany studies have been conducted on the impact of animal feed on isoflavones and their metabolite concentrations in bovine milk, but few studies have focused on the development and validation of analytical protocols for quantifying these compounds in biological matrices other than milk and plants. The purpose of this study was to develop a method that would enable four isoflavones and equol in cows’ feces and digestive fluids to be quantified simultaneously. The method is based on aglycones released by methanolic ultrasound-assisted extraction, followed by enzymatic hydrolysis and high-performance liquid chromatography tandem–mass spectrometry analysis. The sample preparation was optimized using the Box–Behnken design. The selected extraction conditions were 80°C, 10 min, and 50% methanol for digestive fluids and 70°C, 35 min, and 60% methanol for feces. For hydrolysis, the selected conditions were 37°C, 1 h, and a pH of 6 for both matrices. The analytical method showed a good linear regression model ranging from 5 to 125 ng mL−1. Both inter- and intraday accuracy (≤8.5 and ≤12.3%) and precision (≤11.1 and ≤15.2%) were suitable. No matrix effects were found. There was good repeatability and extract stability for at least 4 days of storage at − 20 and 6°C. All recoveries were in the acceptable range of 70–120% for both matrices, except for biochanin A in feces, where the value was approximately 43%. This sensitive and reliable method will be useful for monitoring the passage of isoflavones and equol in the digestive system of ruminants.

Hydrometallurgical separation of copper and cobalt from lithium-ion batteries using aqueous two-phase systems

A new green hydrometallurgical method was developed for the selective extraction of copper and cobalt from spent lithium-ion batteries, using an aqueous two-phase system (ATPS) extraction technique. The method was optimized for the extraction of Cu(II) and Co(II), considering the influence of the following parameters: type and concentration of extractant (1-(2-pyridyl-azo)-2-naphthol (PAN), 1-nitroso-2-naphthol (1N2N), or bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272)); pH (1.00, 6.00, or 11.0); ATPS-forming electrolyte (Na2SO4 or Na3C6H5O7); tie-line length (TLL) of the system; and mass ratio of the top and bottom phases (mTP/mBP). The recovery efficiency was evaluated in terms of the extraction percentage (%E) and the separation factor (S) between copper and cobalt. The best conditions for selective extraction were achieved using an ATPS composed of L64+Na2SO4+H2O, with pH=6.00, TLL=50.3% (w/w), mTP/mBP=1, and PAN as the extracting agent, which resulted in βCu,Co=3.22×102. The method was subsequently applied to a real lithium-ion battery sample, previously leached with HCl and HNO3. Improved separation of copper and cobalt was achieved using successive extraction steps, resulting in βCu,Co=5.40×105. A stripping assay was also performed, and after a single step, 70.5% of the copper was available for an electrowinning process.

Pilot‐scale supercritical CO2 extraction of edible insect oil from Tenebrio molitor L. larvae – Influence of extraction conditions on kinetics, defatting performance and compositional properties

In view of industrial fractionation processes for edible insects, supercritical CO2 extraction of Tenebrio molitor larval oil was studied. The influence of extraction parameters on defatting of larvae was investigated using a full factorial design. Furthermore, the effect of operating conditions on extraction kinetics, fatty acid composition, and acidity of mealworm oil was evaluated. Pressure, time, and their interaction showed the most significant effects on defatting. Maximal defatting (95%) was achieved at 400/250 bar, 45°C, and 105 min. Extraction kinetics revealed that incrementing pressure increased the solubility of mealworm oil in SC–CO2 enabling faster extraction. Extracted oils contained 72% unsaturated fatty acids, and oleic acid accounted for 42% of total FAME. Oil composition and acidity were found to be affected by extraction parameters showing the highest amount of low molecular and free fatty acids after slow extraction at 250 bar and 65°C. Use of selective extraction conditions enabled simple time‐dependent fractionation and deacidification yielding fractions with tailored fatty acid profiles or facilitating subsequent refining processes, respectively. Defatting performance and oil composition were not substantially different when using hexane as a solvent in comparison to SC–CO2. Mealworm larvae can be effectively defatted using SC–CO2 at high pressure and moderate temperature, yielding two valuable fractions: oil‐ and protein‐rich residue.Practical applications: Mealworm larvae are promising candidates for the inclusion of edible insects in the western food and feed industry due to modest breeding demands, existing rearing knowledge, and high contents of protein and fat. The development of fractionation processes for the production of standardized insect bulk materials and incorporation in feed or food in analogy to soy and other plant raw materials rich in fat and protein will help gain industrial applicability and enhance consumer acceptance. Depending on the processing approach, a defatting step is crucial prior to protein extraction. The results of this study indicate that SC–CO2 extraction is suitable for achieving a high yield of solvent‐free oil and a protein‐enriched, solvent‐free residue at low extraction temperatures. Both fractions can be further refined and purified in order to achieve valuable intermediates for food and feed applications.The SC–CO2 extraction of mealworms yielded highly unsaturated oil and a defatted residue containing protein and chitin. The operating parameters clearly affected the defatting performance and the extraction rate.

Pulsed electric field and pH assisted selective extraction of intracellular components from microalgae Nannochloropsis

The study was aimed at investigation of the potential of pulsed electric field (PEF) pre-treatment as a preliminary step of pH-assisted aqueous extraction of algae components from microalgae Nannochloropsis suspensions. The PEF and sonication (S) were compared as pretreatment methods. They were applied at normal (pH=8.5) and basic (pH=11) conditions, and supplementary basic extraction (at pH=11) was done. The extracts were analyzed for content of pigments, proteins, carbohydrates, total phenolic compounds and antioxidant capacity. The colloidal stability of PEF- and S-pretreated suspensions was also evaluated. The data evidence that PEF technique allows selective extraction of a portion of pure proteins that are different from proteins extracted from S-pretreated suspensions. The discovered effects have shown the advantages of PEF-pretreatment at normal conditions (pH=8.5) and supplementary extraction at basic conditions (pH=11) for selective extraction of different intracellular components.

A Novel Viewpoint of Imidazolium Salts for Selective Extraction of Cobalt in the Presence of Nickel from Acidic Thiocyanate Solutions by Ionic-Liquid-Based Solvent-Extraction Technique

In this study, the selective extraction and stripping conditions of Co(II) from acidic thiocyanate solution containing Co(II) and Ni(II) by ionic-liquid-based solvent-extraction technique using symmetric and asymmetric imidazolium bromide salts substituting butyl and isobutyl groups were experimentally optimized. The molecular structure effect of imidazolium bromide salts (IMs) have been determined as main factor to extract Co(II). The executive parameters on stripping and extraction processes, such as IMs concentration, pH, thiocyanate concentration, stripping reagent type, and concentration, were experimentally investigated. Molecular variation of organometalic complex (adduct) consisting of IMs and Co-SCN, were illuminated by comparision of ATR-FTIR spectrums of pure and Co-SCN loaded IMs. Stoichiometric rates of the adduct was verified with slope analysis. In light of these examinations, Co(SCN)3− has been determined as prominent Co-SCN species in aqueous media. Symetric IMs were identified as more effective than asymmetric ones on selective separation of Co(II) from Ni(II). Under optimum conditions, 99.20% of Co(II) was extracted and 93.33% of Co(II) was recovered with higher separation factors especially in diluted solution, whereas, Ni(II) extractions were negligible. We have concluded that the separation power of this study is high in Co(II)/Ni(II) containing dilute solutions and it can be used in preconcentration purposes effectively.

Dendrimer grafted nanoporous silica as a new coating for headspace solid-phase microextraction fibers

Preparation of a SBA-15 silica-supported dendrimer.

Determination of fungicides in white grape bagasse by pressurized liquid extraction and gas chromatography tandem mass spectrometry

Ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) followed by gas chromatography–triple quadrupole-mass spectrometry (GC TQ-MS) were used for the rapid determination of 11 fungicides (metalaxyl, cyprodinil, procymidone, iprovalicarb, myclobutanyl, kresoxim-methyl, benalaxyl, fenhexamide, tebuconazole, iprodione and dimethomorph) in white grape bagasse. The extractions were optimized on real non-spiked samples by means of experimental design and the optimal conditions were selected to achieve the method validation. The PLE procedure showed much higher efficiency than UAE for the target fungicides. Under the selected extraction conditions, PLE showed satisfactory linearity, repeatability and reproducibility. Recoveries for the majority of studied fungicides were higher than 80% with relative standard deviations (RSD) lower than 12%. Limits of detection (LODs) for GC TQ-MS were very low, at the sub ngg−1 for the majority of the target fungicides, well below the European maximum residue limits (MRLs) for wine and table grapes, and vine leaves. Eighteen white grape bagasse samples were analyzed and nine out of eleven targets were detected in the samples. Seven of them were detected in more than 50% of the samples and most samples contained at least four of the target analytes. The most frequently found compounds were tebuconazole and dimethomorph with concentrations between 1.6–130 and 2.0–1788ngg−1, respectively. Some samples showed high levels of many of the studied fungicides (high ngg−1, even μgg−1 for cyprodinil, fenhexamide, iprodione and dimethomorph), but all of them below the European maximum residue limits (MRLs) for wine grapes.

Custom synthesis of polymeric adsorbent for extraction of furosemide and bumetanide from human urine

Here we present a custom design of polymeric adsorbent for the selective extraction and pre-concentration of furosemide and bumetanide. In order to select functional monomers, which are able to provide strong binding with target analytes, computational modelling of molecular interactions and a screening of virtual library of monomers were applied. Diethylaminoethylmethacrylate (DEAEM) was selected as the best monomer capable of forming strong complexes with furosemide and bumetanide. Conditions for selective solid phase extraction (SPE) of the diuretics from human urine using custom-designed adsorbent were optimized. It was found that the computationally designed adsorbent demonstrated very high capacity (equal 30 g kg−1) towards furosemide and bumetanide. The application of the developed resin reduced significantly the amount of interfering compounds in the analysed sample and allowed the direct measurements of diuretics of interest using generic ultraviolet spectrometer without need in expensive instrum...

Is nudge an effective public health strategy to tackle obesity? Yes

Users of single-use (SU) components need extractables data to demonstrate material safety for regulatory bodies before incorporation in the biopharmaceutical process. In this context, the correct use of such extractables...

Advances in the Understanding of the Chemical Reactions Responsible for Bread Flavour Quality

This work aimed at analysing bread extracts obtained under headspace and artificial mouth conditions in order to study the reactions responsible for bread flavour quality. Selected extraction conditions were first compared according to the odour and aroma representativeness of the bread extracts. The optimal conditions were then applied to extract volatiles of a conventional gluten bread formulation and an innovative gluten-free bread formulation. Results reveal that an extraction duration of 10 min in the artificial mouth was sufficient to obtain a representative aroma extract. Yet, 30 min of headspace extraction were necessary to obtain a representative odorant extract. The comparison between these both extracts shows that significantly higher quantities of bread compounds were extracted with artificial mouth. This innovative device could thus be used to better understand the mechanisms involved in the formation of those volatiles that are responsible for the perceived bread odour and aroma.

Interaction of basalt with orthophosphoric acid

Physicochemical modeling is used to study the decomposition of basalt by orthophosphoric acid. The equilibrium compositions of the liquid and solid phases of the Al-Fe-Ca-Mg-Na-Si-P-O-H system are calculated. The effects of the acid concentration and solid-to-liquid ratio on the composition of reaction products and the degrees of extraction of iron, aluminum, magnesium, calcium, sodium, and silicon into solution are determined. Conditions for selective extraction of the components into liquid phase are estimated.

Interaction of basalt with hydrochloric acid

Physicochemical modeling and experimental investigations are performed to study the interaction of basalt with hydrochloric acid. The equilibrium compositions of the liquid and solid phases of the basalt-hydrogen chloride-water system are calculated. The effects of the hydrochloric acid concentration and solid-to-liquid weight ratio on the phase composition of reaction products are quantified, and the degrees of extraction of iron, aluminum, calcium, sodium, and silicon into liquid are determined. The results of physicochemical modeling are compared with the experimental data. Conditions for selective extraction of the basalt components into solution are estimated.

DETERMINATION OF HEAVY METALS IN TEXTILE MATERIALS BY ATOMIC ABSORPTION SPECTROMETRY: VERIFICATION OF THE TEST METHOD

Abstract The objective of this research was to identify the analytical steps affecting the quantitative assessment for the determination of heavy metals in textile materials and to test the selected extraction conditions, with the intent of developing a standardized and shared method that would help promote textile products, both in terms of safety for the environment and health of citizens, and of safety for workers exposed during the production process and for end users. The method was applied to a textile materials dyed with a chromium dyestuff at two different concentrations. The metals analyzed were total Cr and Cr VI. The extraction was carried out by means of the artificial perspiration solution, according to the standard adopted by the most important textile ecolabelling schemes operating in the European market. The extract was filtered under vacuum and analyzed by means of atomic absorption spectrometry for total Cr and UV-Visible spectroscopy for Cr VI. The tests were carried out varying some extraction parameters as temperature of the solution, time of contact and material-to-liquor ratio extraction. Finally the metal extraction profit was derived by the determination of total chromium in the ashes. The results show that the quantity of total chromium and CrVI extracted is affected principally by the temperature of the solution and by the material-to-liquor ratio extraction, and less by the time of contact. The percentage of metal extraction profit vary according to the extraction conditions, from 32% to 44%.

Purification of recombinant aprotinin from transgenic corn germ fraction using ion exchange and hydrophobic interaction chromatography

Plants have attracted interest as hosts for protein expression because of the promise of a large production capacity and a low production cost. However, recovery costs remain a challenge as illustrated for recovery of recombinant aprotinin, a trypsin inhibitor, with removal of native corn trypsin inhibitor from transgenic corn (Azzoni et al. in Biotechnol Bioeng 80:268-276, 2002). When expression is targeted to corn grain fractions, dry milling can separate germ and endosperm fractions. Hence, only the product-containing fraction needs to be extracted, reducing the cost of extraction and the impurity level of the extract. Selective extraction conditions can reduce impurity levels to the point that low-cost adsorbents can result in relatively high purity levels. In this work, we attempted to achieve comparable purity with these lower cost methods. We replaced whole grain extraction and purification of recombinant aprotinin with sequential trypsin affinity and IMAC steps with an alternative of germ fraction extraction and purification with ion exchange and hydrophobic interaction chromatography (HIC). Using germ extraction at acidic pH supplemented with heat precipitation to remove additional host proteins resulted in a higher specific activity feed to the chromatographic steps. The cation exchange step provided 7.6x purification with 76.4% yield and no sodium dodecyl sulfate-polyacrylamide gel electrophoresis detectable native corn trypsin inhibitor. After the HIC step (2.7x step purification with 44.0% yield), the final product had a specific activity that was 75.3% of that of the affinity-purified aprotinin.

Selectivity in the extraction of 2- quinolone alkaloids with supercritical CO2

This work describes the conditions for selective extraction of the alkaloids in Andreadoxa flava (Kallunki). The experiments were performed in a pilot plant SFE 500, in the following conditions. Extractor pressures 206.8 x 10(5), 241.3 x 10(5), 275.8 x 10(5) and 310.3 x 10(5) Pascal and pressures of 137.9 x 10(5), 69.0 x 10(5) and 55.2 x 10(5) Pascal for separators 6, 7 and 8 respectively. The temperatures were 40 °C in the extractor and 20 ºC in the separators. The samples, extracted from A. flava leaves, were analysed by ¹H NMR and GC/FID as well as by comparison with standards. This procedure allowed the identification for the first time of the 2-quinolone alkaloid 8-methoxy-N-methyl-flindersine in A. flava leaves of the. In addition, zanthophylline, 5-methoxyalmene and 8-methoxyflindersine were identified as the main alkaloids in leaves. Under the best conditions for zanthophylline extraction it was possible to obtain a purity of 79.4% while with other phytochemical technique 55.5% was obtained.

Focused microwave-assisted extraction combined with solid-phase microextraction and gas chromatography–mass spectrometry for the selective analysis of cocaine from coca leaves

An effective combination of focused microwave-assisted extraction (FMAE) with solid-phase microextraction (SPME) prior to gas chromatography (GC) is described for the selective extraction and quantitative analysis of cocaine from coca leaves ( Erythroxylum coca). This approach required switching from an organic extraction solvent to an aqueous medium more compatible with SPME liquid sampling. SPME was performed in the direct immersion mode with a universal 100 μm polydimethylsiloxane (PDMS) coated fibre. Parameters influencing this extraction step, such as solution pH, sampling time and temperature are discussed. Furthermore, the overall extraction process takes into account the stability of cocaine in alkaline aqueous solutions at different temperatures. Cocaine degradation rate was determined by capillary electrophoresis using the short end injection procedure. In the selected extraction conditions, less than 5% of cocaine was degraded after 60 min. From a qualitative point of view, a significant gain in selectivity was obtained with the incorporation of SPME in the extraction procedure. As a consequence of SPME clean-up, shorter columns could be used and analysis time was reduced to 6 min compared to 35 min with conventional GC. Quantitative results led to a cocaine content of 0.70 ± 0.04% in dry leaves (RSD < 5%) which agreed with previous investigations.

Development of a molecularly imprinted polymer based solid-phase extraction of local anaesthetics from human plasma

Molecular imprints selective for a homologous series of local anaesthetics, including bupivacaine, ropivacaine and mepivacaine, were prepared and the resultant polymers were used for solid-phase extraction of human plasma. The template was a structural analogue, pentycaine, which was imprinted in methacrylic acid–ethylene glycol dimethacrylate copolymers. Equilibrium ligand binding experiments using radiolabelled bupivacaine were performed to characterize the imprinted polymers, as well as to identify optimal conditions for selective extraction of plasma samples. Dilution of the plasma prior to extraction with citrate buffer pH 5.0 containing ethanol and Tween 20 was found optimal for selective imprint–analyte binding, and for reduction of non-specific adsorption of lipophilic contaminants to the hydrophobic MIP surface. Wash steps using 20% methanol in water followed by a solvent switch to 10% ethanol in acetonitrile removed contaminants and strengthened the selective imprint–analyte binding. Elution under basic conditions using triethylamine–water–acetonitrile mixtures recovered bupivacaine in 89% yield with superior selectivity over elution under acidic conditions. The final protocol extracted trace levels of ropivacaine and bupivacaine from human plasma and allowed determination of bupivacaine in the range of 3.9–500 nmol L −1 and ropivacaine in the range of 7.8–500 nmol L −1 with inter-assay accuracies of 94–99 and 95–104%, respectively. This present investigation provides an improved understanding of approaches available for optimization of protocols for molecular-imprint based solid-phase extraction of plasma samples.

Determination of Irgarol 1051 in Western Mediterranean sediments. Development and application of supercritical fluid extraction–immunoaffinity chromatography procedure

A supercritical fluid extraction (SFE) procedure for Irgarol 1051 (i.e. 2-(tert-butylamino)-4-(cyclopropylamino)-6-(methylthio)-1,3,5-triazine) determination in marine sediments, which minimises the solvent usage, is developed and compared to a conventional extraction technique (i.e. sonication). First, the use of methanol (MeOH) in the presence of trifluoroacetic acid (TFA) as secondary modifier of supercritical carbon dioxide was evaluated. Extraction efficiency was strongly dependent on the modifier content but lesser on pressure (100–410 bar) and temperature (60–200°C). In the selected extraction conditions (20% MeOH/TFA 0.65 M, 370 bar, 150°C) recoveries higher than 87% were obtained and the limit of detection was 3 ng g −1 and the relative standard deviation of 10% ( N=3) by GC coupled to mass spectrometry (GC-MS) in the electron impact mode. The developed SFE procedure is more convenient to extract Irgarol 1051 than the agitation plus sonication methods concerning on solvent usage (1.5 vs . 20 mL) being compatible with immunochemical procedures avoiding any solvent transfer step. The developed SFE combined with immunoaffinity chromatography (IAC) is highly selective allowing the determination of Irgarol by gas chromatography with nitrogen–phosphorus detection or in sediments at low ng g −1 level (11–35 ng g −1) from Mediterranean marina and harbour sediments.

Alternative extraction methods for Zearalenone: Microwave Assisted Extraction and Accelerated Solvent Extraction

Zearalenone (ZON) was extracted from wheat and corn by using Microwave Assisted Extraction and Accelerated Solvent Extraction. A factorial design approach was applied to evaluate the influence of the most important extraction parameters such as temperature, time and solvent extraction mixture on fortified cereals. ZON was determined by LC-MS without performing any clean-up after the extraction to better evaluate the extraction efficiency. The selected extraction conditions were tested on samples which had been previously used in an international proficiency test. Applying the selected extraction conditions both alternative extraction procedure provided satisfactory results comparable to the most commonly used method.