Extraction-based Procedure Research Articles

Neodymium recovery from permanent magnets: A breakthrough approach using Deep Eutectic Solvents and Mica

The NdFeB permanent magnets, that contain Neodymium (Nd) are invariably required for the renewable energy industries. Conventional solvent extraction-based procedures for extracting neodymium from these magnets have considerable drawbacks, including high energy consumption, the usage of chemicals, and the production of secondary organic waste. This study presents an innovative approach to address these challenges. To our knowledge, this study is the first to utilise the combination of salicylic acid and choline chloride (SA-ChCl) to make deep eutectic solvents (DESs) for leaching neodymium from discarded neodymium-ferrite magnets and mica for recovery process. Several analyses were performed to verify the efficacy of this strategy. The successful synthesis of DESs was confirmed by FTIR measurement, and Nd adsorption on the adsorbent was shown to be remarkable. Aliphatic hydrocarbons were detected in the DESs by NMR spectroscopy, and the adsorbent's crystalline structure and surface shape were shown, respectively, by XRD patterns and SEM micrographs. It was discovered that variables including the solid/liquid mass ratio, leaching period, and temperature had an impact on both the leaching efficiency and the separation factor. The ideal parameters were discovered to be 1.2 g/L, 200 rpm, and 60 °C, respectively, during the study's investigation into the effects of mica dose, stirring rate, and temperature on mica adsorption. With a maximum leaching effectiveness of 97 %, this technique offers hope for DESs reuse. The maximum desorption efficiency was also demonstrated by calcium chloride, allowing for efficient recycling of the mica adsorbent. Interestingly, a model of an artificial neural network (ANN) with 10 neurons and one hidden layer was created to predict the greatest Nd recovery, validating the efficiency of the DESs-Mica technique in boosting Neodymium recovery from discarded permanent magnets.

A solvent extraction-based procedure for removal of 46Sc impurity from reactor produced [45Ca]CaCl2 for its potential use in bone pain palliation

Calcium-45 [T½ = 163 d, Eβ (max) = 0.3 MeV] is a pure β− emitting radioisotope which can be envisaged for potential use in palliative care of pain due to skeletal metastases of primary cancer. During production of 45Ca in nuclear reactor via 44Ca (n,γ) 45Ca route, 46Sc is co-produced as a radionuclidic impurity. In this study, we have optimized a single-step solvent extraction procedure for complete removal of 46Sc impurity from [45Ca]CaCl2. The purified radiotracer was administered intravenously in normal Wistar rats and preferential bone uptake could be demonstrated by ex vivo biodistribution studies.

Robotic RNA extraction for SARS-CoV-2 surveillance using saliva samples.

Saliva is an attractive specimen type for asymptomatic surveillance of COVID-19 in large populations due to its ease of collection and its demonstrated utility for detecting RNA from SARS-CoV-2. Multiple saliva-based viral detection protocols use a direct-to-RT-qPCR approach that eliminates nucleic acid extraction but can reduce viral RNA detection sensitivity. To improve test sensitivity while maintaining speed, we developed a robotic nucleic acid extraction method for detecting SARS-CoV-2 RNA in saliva samples with high throughput. Using this assay, the Free Asymptomatic Saliva Testing (IGI FAST) research study on the UC Berkeley campus conducted 11,971 tests on supervised self-collected saliva samples and identified rare positive specimens containing SARS-CoV-2 RNA during a time of low infection prevalence. In an attempt to increase testing capacity, we further adapted our robotic extraction assay to process pooled saliva samples. We also benchmarked our assay against nasopharyngeal swab specimens and found saliva methods require further optimization to match this gold standard. Finally, we designed and validated a RT-qPCR test suitable for saliva self-collection. These results establish a robotic extraction-based procedure for rapid PCR-based saliva testing that is suitable for samples from both symptomatic and asymptomatic individuals.

Removal of pesticide residues from beeswax using a methanol extraction-based procedure: A pilot-scale study

In the present study, a batch mode procedure has been developed to remove pesticides from beeswax coming from bee farms. The beeswax is treated by an Extraction Process with methanol at 65 °C followed by an Adequation Process with water at 70 °C. This procedure can reduce the beeswax contamination load by values of around 80%–90% for the acaricides usually present in beeswax such as Coumaphos, Chlorfenvinphos, tau-Fluvalinate and Acrinathrin, at concentration ranges of 1800–2600 μg/kg, 140–300 μg/kg, 100–300 μg/kg and 160–470 μg/kg, respectively. This process is also able to eliminate other pesticides, such as Amitraz, which are typically present in beeswax samples at high concentrations. Similarly, it is efficient in removing further compounds such as Propiconazole, Bromopropylate, Chlorpyrifos, Cypermethrin, Diazinon and Fenamiphos, which are present at lesser quantities depending on their origin and surrounding pesticide treatment history. The procedure’s operating parameters were atmospheric pressure, a 20 °C–70 °C temperature range and 200 rpm. Up to 80% of the methanol used in the extraction was recycled and the waste generated was easy to manage. The quality of the decontaminated beeswax obtained has similar properties to those of virgin beeswax and can be used to manufacture ecological hives or galenic formulations. Beeswax quantities of 1, 20 and 75 kg were treated to determine the optimal operating conditions that would make it possible to extend the process to the industrial scale. All the equipment utilized (e.g. agitated tanks, temperature control, centrifuges and distillation equipment) are basic tools commonly used in the chemical industry.

Assay of Endogenous 3,5-diiodo-L-thyronine (3,5-T2) and 3,3'-diiodo-L-thyronine (3,3'-T2) in Human Serum: A Feasibility Study.

3,5-diiodo-L-thyronine (3,5-T2) is an endogenous derivative of thyroid hormone with potential metabolic effects. It has been detected in human blood by immunological methods, but a reliable assay based on mass spectrometry (MS), which is now regarded as the gold standard in clinical chemistry, is not available yet. Therefore, we aimed at developing a novel ad-hoc optimized method to quantitate 3,5-T2 and its isomers by MS in human serum. Serum samples were obtained from 28 healthy subjects. Two ml of serum were deproteinized with acetonitrile and then subjected to an optimized solid phase extraction-based procedure. To lower background noise, the samples were furtherly cleaned by hexane washing and acetonitrile precipitation of residual proteins. 3,5-T2 and its isomers 3,3′-T2 and 3′,5′-T2 were then analyzed by HPLC coupled to tandem MS. Accuracy and precision for T2 assay were 88–104% and 95–97%, respectively. Recovery and matrix effect averaged 78% and +8%, respectively. 3,5-T2 was detected in all samples and its concentration averaged (mean ± SEM) 41 ± 5 pg/ml, i.e., 78 ± 9 pmol/l. In the same samples the concentration of 3,3′-T2 averaged 133±15 pg/ml, i.e., 253±29 pmol/l, while 3′,5′-T2 was not detected. 3,5-T2 concentration was significantly related to 3,3′-T2 concentration (r = 0.540, P < 0.01), while no significant correlation was observed with either T3 or T4 in a subset of patients in which these hormones were assayed. In conclusion, our method is able to quantify 3,5-T2 and 3,3′-T2 in human serum. Their concentrations lie in the subnanomolar range, and a significant correlation was detected between these two metabolites in healthy individuals.

Antioxidant Capacity of Beetroot: Traditional vs Novel Approaches.

Red beetroot has been ranked among the 10 most potent antioxidant vegetables, although only extraction-based methods have been used to evaluate its total antioxidant capacity. Therefore, the present study aims at comparing the traditional extraction-based method with two more recent approaches (QUENCHER -QUick, Easy, New, CHEap and Reproducible- and GAR -global antioxidant response method), in order to establish their suitability in the case of beetroot. Our results indicate that the total antioxidant capacity of beetroot would be underestimated when using extraction-based procedures, since both QUENCHER and GAR methods resulted in a higher total antioxidant capacity. The effect of a thermal treatment on the total antioxidant capacity of beetroot varies among the methods evaluated and our findings suggest different compounds responsible for the total antioxidant capacity detected in each pre-processing method. Remarkably, the present study demonstrates that the traditional extraction-based method seems useful to screen for (changes in) the "bioavailable" antioxidant potential of the root.

A novel extraction-based procedure for the determination of cadmium in marine macro-algae using HR-CS GF AAS

This work proposes a simple method for the determination of Cd in macro-algae by high-resolution continuum source graphite furnace atomic absorption spectrometry.

Assessment of Antioxidant Potential of Pomegranate Fruit By-Products via a Direct Approach Using a Simple QUENCHER Method.

Fruit and vegetable processing industries produce substantial quantities of phenolic-rich by-products that could be potential sources of natural antioxidants. The measurement of antioxidant activity in plant materials is mostly limited to extraction-based procedures that have several limitations. In this study, a relatively new direct approach, the QUENCHER (quick, easy, new, cheap, and reproducible) procedure was applied to measure total antioxidant capacity in pomegranate fruit by-products, including peel, pith, carpellary membranes, and seeds. Freeze-dried ground samples were directly mixed with free radical solvents in a single operation rather than separating the extract from solid samples. Efficacy of the direct procedure was evaluated against a routine extraction-based procedure using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS); 2,2-diphenyl-1-picrylhydrazyl (DPPH); and ferric reducing antioxidant power assays. Pomegranate peel showed the highest total antioxidant capacity, followed by pith, carpellary membranes, and seeds. Total antioxidant capacity values determined by the direct procedure were significantly higher (P < 0.05) than those measured by the extraction procedure. The obvious advantages of the QUENCHER procedure over extraction-based procedures are that it would reduce the complexity of separating bound phenolics and antioxidant compounds, as well as the time and conditions required for unit extraction operations. The conversion of industrial waste into valuable ingredients would be advantageous for development of pomegranate supplements and added-value products.

Application of high performance liquid chromatography-tandem mass spectrometry for detection of melittin, a characteristic peptide of bee venom

Bee venom is widely used for the manufacturing of cosmetics and pharmaceuticals. A procedure for the detection of melittin, a characteristic component of bee venom, based on high performance liquid chromatography with tandem mass spectrometric detection is reported. Conditions of chromatography-mass spectrometric detection of melittin are selected, and a solid-phase extraction-based procedure for melittin isolation from preparations containing bee venom is developed. The procedure proposed is successfully tested on both raw venom samples and cosmetic and pharmaceutical preparations containing natural bee venom.

The Analysis of Online and Offline Signature Verification Techniques to Counter Forgery

Background: This paper reports precise examination of a few highlight extraction-based procedures for signature check. Dynamic features of Signature are captured for online verification procedure at the time of signing. Offline frameworks deal with the examined picture of a signature. A shot at the Offline Verification of signatures utilizing an arrangement of shape based geometric highlights has been taken. Pattern Slant Angle, Normalized Area, Height, Aspect Ratio, Width, area of signature pixels are the utilized features. Captured image should be Pre-processed to separate the signature part and remove the white noise, before extracting the features. Methods: The framework is at first prepared utilizing a database of signatures acquired from those people whose signatures must be confirmed by the framework. A mean signature is acquired coordinating the above features got from an authenticate test signatures. Findings: The claimed test signature is compared with the mean signature for the purpose of verification. Euclidian distance in the feature space between the claimed signature and the template serves as a measure of similarity between the two. On the off chance that this separation is not as much as a predefined edge (relating to least adequate level of likeness), the test signature is checked to be that of the guaranteed subject else distinguished as a phony.

A novel extraction-based procedure for the determination of trace elements in estuarine sediment samples by ICP-MS

The study proposes a simple and fast extraction-based procedure for the determination of trace elements in estuarine sediment samples by inductively coupled plasma mass spectrometry (ICP-MS). The extraction conditions were optimized using a central composite design. Optimum results were obtained when 100mg of sediment sample was used followed by ultrasound-assisted extraction for 15min with 7.50molL−1 HF (1mL HF) and 3.50molL−1 HNO3 (1mL HNO3 65%m/m). Calibration against aqueous standards was carried out with rhodium as an internal standard. The method was successfully applied for the quantitative extraction of As, Cd, Co, Cr, Cu, Ni, Pb, Sn, V and Zn. Detection limits ranging from 0.02 to 0.1μgg−1 and relative standard deviation lower than 8% were obtained. The method accuracy was assessed by using three certified reference materials and comparing the results from the extraction procedure with those obtained following microwave-assisted digestion of the samples; no statistical differences, based on t-test at a confidence level of 95%, were detected. The proposed method showed to be simple and fast and can be applied for sediment samples with the elimination of the sample digestion step prior to analysis.

An improved method for efficient isolation and purification of genomic DNA from filamentous cyanobacteria belonging to genera Anabaena, Nodularia and Nostoc

Abstract The aim of this work was to develop an improved method for isolation and purification of genomic DNA from filamentous cyanobacteria. The method described here employs a modified phenol extraction-based procedure. It allowed us to obtain a high yield (60–620 μg/g wet weight, depending on the cyanobacterial strain) of pure and undegraded genomic DNA (A260/A280 ratio of about 1.8 and A260/A230 ratio of about 2.0). Genomic DNA, isolated from cyanobacteria belonging to the genera Anabaena, Nodularia and Nostoc has been successfully used for construction of gene libraries. Thus, this method can be used in procedures requiring highly purified cyanobacterial DNA.

Analysis of octopamine in human doping control samples

The biogenic amine octopamine [4-(2-amino-1-hydroxyethyl)phenol] is prohibited in sports owing to its stimulating and performance-enhancing properties. Adverse analytical findings in athletes' doping control samples commonly result from surreptitious applications; however, the occurrence of octopamine in nutritional supplements and in selected invertebrates as well as the assumption that its N-methylated analog synephrine [4-(1-hydroxyethyl-2-methylamino)phenol, not banned by anti-doping authorities but currently monitored in prevalence studies) might be converted in-vivo into octopamine have necessitated a study to investigate the elimination of synephrine and octopamine present in over-the-counter products. Urine samples collected after administration of nutritional supplements containing octopamine and/or synephrine as well as urine samples collected after therapeutic application of octopamine- or synephrine-containing drugs were analyzed using a validated solid-phase extraction-based procedure employing a weak cation exchange resin and liquid chromatographic/tandem mass spectrometric detection with electrospray ionization and multiple reaction monitoring. In the case of therapeutic octopamine application, the urinary concentration of the target compound increased from baseline levels below the lower limit of detection to 142 µg/mL, while urine samples collected after synephrine as well as dietary supplement administration did not yield any evidence for elevated renal excretion of octopamine.

Comparison of the efficiency of different extraction methods for the simultaneous determination of mycotoxins and pesticides in milk samples by ultra high-performance liquid chromatography-tandem mass spectrometry

A rapid multi-analyte method has been developed for the simultaneous determination of pesticides and mycotoxins in milk by ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS). A variety of methodologies has been evaluated, including solid-phase extraction (SPE), "dilute-and-shoot" (liquid-liquid extraction-based procedures), and QuEChERS (quick, easy, cheap, effective, rugged, and safe)-based methods. The optimization and development process was carried out considering that the maximum residue level for aflatoxin M1 (AFM1) in milk in the European Union (EU) is set at 0.05 μg kg(-1), which is the lowest tolerance in the target compounds. The selected method consisted of an extraction by SPE using C18 as sorbent and methanol as elution solvent. The final determination was performed by UHPLC-QqQ-MS/MS. Matrix-matched standard calibration was used for quantification, obtaining recoveries in the range 60-120% with relative standard deviations <25%, at three spiking levels: 0.5, 10, and 50 μg kg(-1) (ten times lower for AFM1). Limits of quantification ranged from 0.20 to 0.67 μg kg(-1), which were always below or equal to the established tolerance levels by the EU. Finally, the selected method was applied to different types of milk.

Rapid and sensitive high performance liquid chromatographic method for the determination of itraconazole and its hydroxy-metabolite in human serum

Published high performance liquid chromatographic (HPLC) methods for the determination of itraconazole (ITZ) in biological matrices are labor intensive, extraction-based procedures which operate at a pH approaching the limit of column tolerance, and unless modified, cannot measure its hydroxy-metabolite (OH-ITZ). A protein precipitation-based method requiring no solvent extraction and utilizing a base-deactivated C18 analytical column to minimize peak tailing is described herein. Calibration curves for OH-ITZ and ITZ were linear from 25–1500 ng ml −1 ( r 2≥0.999). Intra-assay relative standard deviations (R.S.D.) were below 12%. Inter-assay R.S.D. were below 14%. This method provides a rapid means for the accurate and precise determination of both OH-ITZ and ITZ concentrations in human serum.

Direct determination of plasma endothelin-I by chemiluminescence enzyme immunoassay

A highly sensitive sandwich-type chemiluminescence enzyme immunoassay for plasma endothelin-I (ET-1), involving no extraction steps, has been developed. Two populations of polyclonal antibodies were used in the present study: One is specific to the C-terminus of the endothelin family of peptides; the other, a Fab' fragment against the N-terminal core region of ET-1, is coupled with horseradish peroxidase (HRP). Labeled HRP activity was measured by using an enhanced chemiluminescence reaction of luminol/hydrogen peroxide. The assay was sensitive enough to detect 0.5 ng/L (0.05 pg/well) of plasma ET-1 and had no significant cross-reactivities with other related peptides, including endothelin-3 and the endothelin precursor peptide, big ET-1. Reliability of the assay was confirmed by comparison with an extraction-based procedure and a commercial kit.

Determination of Ketorolac in Human Plasma by High Performance Liquid Chromatography After Automated On-Line Solid Phase Extraction

Abstract An automated solid phase extraction-based procedure for the determination of ketorolac in human plasma was developed and validated. Solid phase extraction of ketorolac tromethamine and ketoprofen (internal standard) was performed on disposable C-18 cartridges directly from plasma samples spiked with the corresponding standards after dilution with saline. All operations were performed automatically by means of a switching-valve assembly in the sample preparation module (Prospekt system), and sample analysis were carried out by on line connection with the HPLC system. Linearity of the analytical methodology was assessed at the concentration range 25–2500 ng/mL ketorolac tromethamine. However, accurate and precise determinations at 5 and 10 ng/mL were obtained by the use of weighing in calibration curve fitting. The mean absolute recoveries for ketorolac tromethamine and the internal standard were 87.7% and 72.9% respectively. Respective intra- and inter-assay precision values were below 7.2 and 18....