Simple Extraction Research Articles

Evaluation of an electricity-independent method for IS2404 Loop-mediated isothermal amplification (LAMP) diagnosis of Buruli ulcer in resource-limited settings.

Buruli ulcer (BU) caused by Mycobacterium ulcerans (MU) is a devastating necrotic skin disease. PCR, recommended for confirmation of BU by WHO, requires an adequately equipped laboratory, therefore often delaying timely diagnosis and treatment of BU patients in remote settings. Loop-mediated isothermal amplification (LAMP) is a PCR-based protocol for isothermal amplification of DNA that has been suggested for diagnosis of BU in low-resource settings. This is an exploratory diagnostic test evaluation study, with an embedded qualitative sub-study. Its aims are two-fold: First, to evaluate a simple rapid syringe-based DNA extraction method (SM) in comparison with a more elaborate conventional DNA extraction method (CM), followed by a LAMP assay targeting IS2404 for the detection of MU, either using a commercially available pocket warmer (pw) or a heat block (hb) for incubation. Second, to complement this by exploring the diagnostic workflow for BU at a community-based health centre in an endemic area in rural Ghana as an example of a potential target setting, using interviews with researchers and health care workers (HCWs). Diagnostic test evaluation results are discussed in relation to the requirements of a target product profile (TPP) for BU diagnosis and the target setting. A protocol using SM for DNA extraction followed by IS2404 PCR (IS2404 PCRSM) was able to identify MU DNA in 73 out of 83 BU clinical specimens submitted for diagnosis. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of IS2404 PCRSM were 90.12%, 100%, 100% and 65.21% respectively, as compared to the reference standard IS2404 PCR in combination with a standard extraction protocol for mycobacterial DNA. Evaluation of the LAMP assay on 64 SM DNA extracts showed a sensitivity, specificity, PPV and NPV of 83.6%, 100%, 100% and 50%, respectively, using either pocket warmer (pwLAMPSM) or heat block (hbLAMPSM) for incubation of the reaction, as compared to the same reference standard. The limit of detection of pwLAMPSM was found to be 30 copies of the IS2404 target. Interview findings explored barriers to BU diagnosis and treatment, including perceptions of the disease, costs, and availability of transport. Participants confirmed that a diagnosis at the PoC, in addition to screening based on clinical criteria, would be advantageous in order to prevent delays and loss to follow-up. The high diagnostic and analytic accuracy of the pwLAMP, evaluated by us in combination with a syringe-based DNA extraction method, supports its potential use for the rapid detection of MU in suspected BU samples at the community or primary health care level without reliable electricity supply. Further optimization needs include a lysis buffer, evaluation directly at the PoC and/or other sites, assessing staff training requirements and quality control.

Rapid and simple dual extraction for the analysis of lipids and autoantigenic peptides within phosphatidylserine-liposomes

Autoimmune diseases are a major health concern in developed countries. Currently, only palliative treatments based on anti-inflammatories and immunosuppressors are available. A novel antigen-specific therapy that uses a physiological process of tolerance generation is being developed. This is plausible by using phosphatidylserine rich liposomes (PS-liposomes), which bio-mimic apoptotic cells, encapsulated with the autoantigen responsible of generating the autoimmunity. In this way, tolerance against the own cells or tissues that were considered hostile can be achieved. In addition, only by changing the encapsulated peptide, different autoimmune diseases can be treated. Efficacy of this approach was demonstrated in type I diabetes, rheumatoid arthritis, multiple sclerosis, and myasthenia gravis.In the regulatory pre-clinical phase, analytical methodologies to evaluate the quality of the product need to be developed. In this regard, identification and quantification of the encapsulated peptide and lipids are considered critical quality attributes. In this study, a rapid and simple liquid–liquid extraction procedure, based on Bligh-Dyer method, is described for dual extraction of peptides and lipids within PS-liposomes formulation. This single step allows the separation of lipids and the encapsulated peptide in two different phases. For the subsequent analysis, two different HPLC methods were developed. The organic phase, which contains the lipids was analysed by HPLC-ELSD, while the aqueous phase, containing the encapsulated peptide, was analysed by HPLC-UV. Both methods were also validated in terms of accuracy, precision, linearity, LOD and LOQ. The extraction procedure has demonstrated highly efficient separation of lipids and peptides, avoiding interferences between them in the quantification.

Improved Temperature-Scalable DC model for SiC power MOSFET including Quasi-Saturation effect

In this paper, accurate temperature-dependent static model for Silicon-Carbide (SiC) power MOSFET is presented. The proposed model is formed by two equations relating to linear and saturation operating regions. In this model, new formalism of the saturation drain current is introduced to consider the peculiar features observed in the I-V static characteristics of the SiC power MOSFET: a) moderate inversion region, or region of low gate voltages and b) quasi-saturation region, region of high gate voltages at which the drain current becomes less sensitive to the increase of gate voltage. In addition, the model captures with high-precision the transition region between linear and saturation region, pinch-off region, noticed in the output characteristics of the SiC power MOSFETs. It will be shown that the model equations ensure continuity and smooth transition between all operating regions. Temperature scaling of the model is carried out by its temperature scaling parameters. The proposed compact model is simple and efficient using reduced number of technology independent parameters. Simple parameter extraction procedure is described that uses an optimizer algorithm based on good experimental initial guess. Excellent agreement is obtained by comparing model to TCAD simulation and device measurement.

New oscillatory features of electrodermal activity signals evaluated in automated mental workload monitoring

Oscillatory components are discriminative features of mental workload monitoring in electrodermal activity (EDA) signals. Currently, most feature extraction techniques mainly focus on time domain or linear techniques but rarely consider the non-stationary nature, individual differences, and recording noise. This study has proposed a new time–frequency feature extraction method based on Tunable Q-factor Wavelet Transform providing an effective quantification of oscillatory behavior of a single transient. The extracted features have been classified using a recurrent neural network with the advantage of dynamic mapping procedure. The proposed method has been evaluated using EDA data acquired during an arithmetic task of five workload levels with both subtle and distinct differences. In a comparative study, the effects of several decomposition parameters and cognitive factors have been explored. Experimental results have shown that it achieves an average accuracy rate of 98.52% for three workload levels discrimination by optimizing the number of features to 3 (features extracted from a low frequency sub-band) from 15 (features extracted from five frequency sub-bands), i.e., 80% feature reduction. The greatest contribution coming fromthe smallest frequency sub-bands has also been obtained. This method is superior to other existing methods in separating 3 to 5 workload levels with both distinct and subtle differences extracting effective oscillatory characteristics. Considering the merits of a simple feature extraction procedure and cost-effectiveness of a single lead EDA signal as well as high discriminability between several workload levels, it provides a trade-off between performance and computational complexity, thus demonstrating its potential for online human-error prevention systems.

Pelatihan Dilan (Distilasi Sederhana) sebagai Upaya Revitalisasi Program Serenisasi di Malang

Codo Village, located in Malang Regency, once held a serenization program. Local PKK women pioneered this program, whose actions were realized through a movement to plant lemongrass throughout the vacant village land to avoid the spread of dengue fever in 2016. A lack of knowledge about the potential of lemongrass plants caused a decline in enthusiasm for the serenization program, marked by many broken lemongrass plants. So, the DILAN (Simple Distillation) training provides a solution to revitalize the serenization program, starting with the formation of cadres, delivery of materials related to lemongrass plants and simple extraction of essential oils using the DILAN method, introduction to e-commerce, supervision and evaluation. The result of this program is that PKK women can produce marketable products from essential lemongrass oil, such as soap, aromatherapy candles, and carbolic acid. The products produced are codo asri and can be obtained from online sales sites. This program can increase the knowledge, productivity and abilities of the population to improve the community's economic status so that the revitalization program can be successfully implemented.

One-Pot Electrosynthesis of Gamma-Butyrolactone (GBL) from Furoic Acid

The catalytic valorization of biomass to afford synthetically useful small molecules is essential for sustainable biorefinery processes. Herein, we present a mild cascaded electrochemical protocol for converting furoic acid (FA), a common biomass-derived feedstock, into a versatile platform chemical, gamma-butyrolactone (GBL). All involved species participate in the desired redox pathway with high selectivity: FA was electrochemically oxidized with 84.2% selectivity to 2(5H)-furanone (2-FO), the olefin of which was then hydrogenated to yield GBL with 98.5% selectivity. We identified that a certain temperature is an important factor in enabling the one-pot reaction as it promotes thermal desorption of the key intermediate. The reaction was scalable to gram-scale, producing high-purity GBL isolated through a simple solvent extraction from a 500-mL electrolysis scale reaction.

One-Pot Electrosynthesis of Gamma-Butyrolactone (GBL) from Biomass-Derived Furoic Acid

An efficient catalytic method to transform biomass into value-added products is critical to promoting a sustainable future. Ideally, such a transformation should be carried out efficiently in mild conditions. Herein, we developed a mild one-pot electrochemical protocol for converting furoic acid (FA), a common biomass-derived feedstock, into a versatile platform chemical, gamma-butyrolactone (GBL). All involved species participate in the desired redox pathway with high selectivity: FA was electrochemically oxidized with 84.2% selectivity to 2(5H)-furanone, the olefin of which was then hydrogenated to yield GBL with 98.5% selectivity. We identified that a specific temperature is an essential factor in enabling the one-pot reaction as it promotes thermal desorption of the key intermediate. The reaction was scalable to gram-scale, producing high-purity GBL isolated through a simple solvent extraction from a 500-mL electrolysis scale reaction.

Efficacy of topical tranexamic acid soaked absorbable gelfoam in relieving post-extraction pain in warfarin patients: a randomized, triple-blinded, split-mouth, active-controlled clinical trial

BackgroundWarfarin patients who need dental extraction face the problem of bleeding and no sufficient hemostasis results in dry socket and postoperative pain. This study aimed to evaluate and compare the efficacy of the topical application of tranexamic acid-soaked absorbable Gelfoam (TXA-Gel) and saline-soaked absorbable Gelfoam (saline-Gel) in relieving postoperative pain following bilateral simple extraction of permanent mandibular molars in warfarin patients.MethodsThis was a randomized, triple-blinded, split-mouth, active-controlled clinical trial. It was performed at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Damascus University, between November 2021 and October 2023. 60 bilateral permanent mandibular molars, which were indicated for simple extraction in 30 warfarin patients randomly assigned into two groups according to the topical hemostatic agents after extraction used: Group 1: control group, saline-Gel (n = 30). Group 2: TXA-Gel (n = 30). A simple randomization method was performed by flipping a coin. The primary outcome measure was the visual analogue scale (VAS). The intensity of pain was evaluated at the baseline (t0), and on the 1st (t1), 2nd (t2), 3rd (t3), 4th (t4), 5th (t5), 6th (t6), and 7th (t7) days following extraction. The Kolmogorov–Smirnov test and the Mann-Whitney U test were performed. The level of significance was set at 0.05 (p < 0.05).ResultsThe mean vas scores was 4.17 ± 1.76 at t1 and decreased to 0.73 ± 0.78 at t7 in the TXA-Gel group. However, in the Gelfoam group, the mean vas scores was 4.83 ± 2.18 at t1 and decreased to 1.80 ± 1.00 at t7. The results of the Mann-Whitney U test showed that there was no statistically significant difference between the two groups at t1 (p = 0.236) and t2 (p = 0.155). However, there was a statistically significance difference at the rest time points (p < 0.05).ConclusionsTXA-Gel played a prominent role in alleviating post-extraction pain in warfarin patients.Trial registrationThe trail was retrospectively registered at the ISRCTN registry (ISRCTN71901901).

Development of a fast and low-cost aqueous based-extraction protocol for the simultaneous extraction and characterization of SiO2 and TiO2 (nano)particles in confectionary products

BackgroundThe determination of (nano)particulate content from food additives has been a long-standing concern for authorities since it is of vital importance for ensuring food safety, regulatory adherence, and transparent consumer information. Nonetheless, a critical step in these determinations is the refinement of a careful and quantitative extraction process for particles that may be found within complex matrices such as confectionery products. The development of new technologies and analysis methods for nanoparticles is ongoing. Whereas new technologies and analysis methods for nanoparticles are being developed, the extraction of (nano)particles of different nature has not been adequately addressed in the literature. ResultsA simple aqueous extraction procedure was found to be suitable for the simultaneous extraction of TiO2 and SiO2 (nano)particles from five confectionery products. Neither the extraction agents (water, lipase, pancreatin and Tris-HCl solutions) nor the methods (manual shaking, ultrasonic bath, ultrasonic probe and ultrafiltration) altered the size, morphology, or aggregation state of either type of particle, as revealed by the micrographs obtained by Transmission Electron Microscopy (TEM). Single-particle ICP-MS (spICP-MS) determined that the optimal conditions for extracting both types of particles involve manual shaking using water as the solvent. Furthermore, the use of enzymes seemed to hinder the determination of both types of particles by spICP-MS. (Nano)particles of TiO2 and SiO2 were detected in all the confectionaries, even though the E171 additive was only labeled in one of them. The average percentage of nanoparticulate TiO2 material in the evaluated products was 30 %, while no nanometer-sized particles of SiO2 were detected. SignificanceEnsuring food safety, regulatory compliance and transparent consumer information relies on getting reliable results that connect with the application of sample treatment procedures for detecting unaltered nanoparticles in food products. The presented research introduces an economical, swift, user-friendly, environmentally responsible, and harmonious extraction method for the concurrent analysis of TiO2 and SiO2 particles in confectionery samples. Furthermore, particles from additives not included in the labeling have been detected, characterized, and quantified in the confectionary products.

Fast Determination of Eleven Food Additives in River Water Using C18 Functionalized Magnetic Organic Polymer Nanocomposite Followed by High-Performance Liquid Chromatography.

A novel magnetic nanomaterial with Fe3O4 as the core, PS-DVB as the shell layer, and the surface modified with C18 (C18-PS-DVB-Fe3O4) had been synthesized by seeded emulsion polymerization. C18-PS-DVB-Fe3O4 retains the advantages of the chemical stability, large porosity, and uniform morphology of organic polymers and has the magnetic properties of Fe3O4. A simple, flexible, and efficient magnetic dispersive solid phase extraction (Mag-dSPE) method for the extraction of preservatives, sweeteners, and colorants in river water was established. C18-PS-DVB-Fe3O4 was used as an adsorbent for Mag-dSPE and was coupled with high-performance liquid chromatography (HPLC) to detect 11 food additives: acesulfame, amaranth, benzoic acid, tartrazine, saccharin sodium, sorbic acid, dehydroacetic acid, sunset yellow, allura red, brilliant blue, and erythrosine. Under the optimum extraction conditions, combined with ChromCoreTMAQC18 (5 μm, 4.6 × 250 mm), 20 mmol/L ammonium acetate aqueous solution and methanol were used as mobile phases, and the detection wavelengths were 240 nm and 410 nm. The limits of detection (LODs) of 11 food additives were 0.6-3.1 μg/L with satisfactory recoveries ranging from 86.53% to 106.32%. And the material could be reused for five cycles without much sacrifice of extraction efficiency. The proposed method has been used to determine food additives in river water samples, and results demonstrate the applicability of the proposed C18-PS-DVB-Fe3O4 Mag-dSPE coupled with the HPLC method to environment monitoring analysis.

Simultaneous extraction and derivatization of biogenic amines during in-situ deep eutectic solvent-based liquid phase extraction from Doogh samples prior to HPLC analysis

A simple and efficient microwave-assisted extraction method using deep eutectic solvent was developed for the simultaneous analysis of four biogenic amines (putrescine, tyramine, cadaverine and histamine) in Doogh (yogurt-based beverage) samples. Important parameters like precipitating agent volume, vortexing time, microwave power, and exposure time were optimized. Zinc sulfate was utilized for proteins precipitation prior to extraction of analytes with the deep eutectic solvent choline chloride/p-anisidine. The analytes were derivatized with dansyl chloride and analyzed by HPLC-DAD. The method showed good linearity (r2 ≥ 0.994) over wide ranges with low limits of detection (0.52–0.78 ng mL−1) and quantification (1.7–2.5 ng mL−1). Extraction recoveries ranged from 68–72 % and relative standard ≤8.1 %. Negligible matrix effects were observed. When the method was applied to real Doogh samples and several biogenic amines were detected. The developed method provided reliable results in terms of sensitivity and selectivity.

Turning Waste into Treasure: Invasive Plant Ambrosia trifida L Leaves as a High-Efficiency Inhibitor for Steel in Simulated Pickling Solutions.

High toxicity is the main reason for the limited application of traditional corrosion inhibitors. Herein, it is critical to find a green, efficient, and long-term stable alternative substitute for the hazardous and conventional corrosion inhibitor. Ambrosia trifida L is widely distributed in fields and riverside wetlands as an invasive plant in China. According to the concept of turning waste into treasure, the extract of Ambrosia trifida L leaves (ATL) has the potential to address this issue due to its natural origin and abundant presence of heterocyclic organics. Therefore, ATL, as a green corrosion inhibitor, is prepared for the first time via a simple water-based extraction method. FT-IR (Fourier transform infrared spectroscopy) and UV-Vis (UV-visible) indicate that ATL extract contains abundant heterocyclic organics with conjugated structures, which exhibit the potential to become a high-efficiency inhibitor. Notably, the active sites of ATL molecules and their interaction with Q235 steel at the molecular/atomic level are revealed via theoretical calculations. The highest Ebinding value observed for the major components in the ATL extract is 259.66 kcal/mol, implying a significant adsorption capacity. The electrochemical results verify that microdose ATL extract can prominently inhibit steel corrosion, and the highest inhibition efficiency (η) is 97.5% (1000 mg/L). Following immersion for 24 h, the η value is enhanced to 99.0%, indicating a reliable and long-term ATL extract protection film is formed on the steel surface in harsh acidic solutions. The results of the weight loss, SEM (scanning electron microscope), and LSCM (laser scanning confocal microscopy) are consistent with the above conclusions. Finally, this study anticipates providing theoretical support for developing novel green plant extract inhibitors and aiding in their application in industrial pickling environments.

Field detection of genetically modified crops: Simple DNA extraction, rapid assay and automatic output on smartphone

Rapid and accurate detection of genetically modified crops (GMC) is significant for crop supervision and genetically modified product labeling. For field detection of GMC, the rapidity and simplicity of the sample pretreatment and detection process are very important. Simplifying the extraction process of DNA in crops and speeding up the detection process are the technical problems that need to be solved. Therefore, this paper provides a field detection method for GMC. First, the selected universal LAMP primers of the chloroplast gene can be used to detect reference genes in nine crops with the most transgenic detection needs. The universal primers of reference genes can not only improve the accuracy of detection, but also omit the design and synthesis of reference gene primers in different crops. Second, a high concentration of DNA can be obtained using simple and fast DNA extraction methods within 5 min. The specific concentration of GuHCl in lysis buffer can accelerate the subsequent nucleic acid amplification reaction. Third, a new probe-LAMP method was established, with high reaction speed and specificity. Using the dual probe-LAMP for transgenic and reference genes in a handheld nucleic acid detector, the detection of GMC can be completed within 25 min. Two different fluorescence signals generated from the LAMP reaction are processed through a special logic gate, and finally three kinds of results of "Positive", "Negative" and "Invalid" are output on a smartphone. This method from sample processing to intelligent result output can achieve accurate, rapid, simple, low-cost, pollution-free field detection of GMC.

Quantification of Recycled Polypropylene Stabilizers for Quality Control by Liquid Chromatography–Tandem Mass Spectrometry Using Simple, Fast and Efficient Ultrasonic Extraction

ABSTRACTIdentifying and quantifying stabilizers in recycled plastics is crucial for utilizing recycled plastics in high‐value‐added applications while avoiding inhibitory effects between additives. However, identifying and quantifying stabilizers composed of multiple chemical classes with different chemical structures presents significant challenges. In this study, the time‐dependent extraction of 17 stabilizers, including six phenolic antioxidants, two phosphite antioxidants, two sulfur antioxidants, two hindered amine light stabilizers (HALS), and five ultraviolet absorbers, from a model polypropylene (PP), was investigated to observe the extraction behavior of these stabilizers. Using ultrasonic extraction on cryogenically ground PP powder, the 17 stabilizers were extracted almost quantitatively within a short duration of 1 h. Utilizing the developed extraction method, stabilizers in 10 types of commercially available recycled PP were quantified by liquid chromatography–tandem mass spectrometry, and no significant matrix effects were observed. On average, nine types of stabilizers were detected per sample, highlighting the complexity of the stabilizer formulations in recycled PP. Sulfur antioxidants and HALS, which require caution due to their inhibitory effects, were found simultaneously in five samples, underscoring the importance of identifying and quantifying stabilizers in recycled PP.

Assessment of remdesivir and its nucleoside metabolite in beagle dogs and healthy humans by liquid chromatography coupled with triple quadrupole mass spectrometry.

The aim of this study was to assess the pharmacokinetics of the existing remdesivir intravenous formulation (100 mg dose) against the newly developed oral formulation (20 mg dose) for remdesivir and its active nucleoside metabolite (GS-441524) in beagle dogs followed by healthy human volunteers. A quantification method for remdesivir and its active nucleoside metabolite (GS-441524) in beagle dog and human plasma has been developed and validated using liquid chromatography coupled to triple quadrupole mass spectrometry detection. The analytical methods for beagle dogs and human differ in the calibration curve range, plasma matrix, processing volume, reconstitution volume and injection volume; however all other parameters were same in both methods. A simple protein precipitation extraction was carried out using acetonitrile containing the internal standard remdesivir D5. Remdesivir and GS-441524 were separated on an Endurus C-18P, 100 × 4.6mm, 3μm column and detected using a mass spectrometer with electrospray ionization in positive ion mode. The ion transitions used were m/z 603.1 → m/z 200.0 for remdesivir, m/z 292.0 → m/z 202.2 for GS-441524 and m/z 608.2 → m/z 205.1 for remdesivir D5. The calibration curve results were linear in beagle dog plasma (2.0-2,000.8ng/ml range for remdesivir and 2.0-1,500.4ng/ml for GS-441524) and human plasma (30.0-4,503.9ng/ml range for remdesivir and 2.0-200.4ng/ml for GS-441524). The recovery was >90% in beagle dog and human plasma. These methods were successfully used to determine the pharmacokinetic parameters of the intravenous injection and subcutaneous tablets dosage forms in beagle dogs and healthy humans.

A green, fluorescent probe employing erythrosine-B for tracing the accidental administration of levamisole in milk and plasma samples.

A simple and sensitive fluorescent probe has been developed and optimized to detect the non-intentional administration of levamisole (LVM). LVM is used as an anthelmintic therapy in cows, and hence, its residues appear in the drained milk until 60 hours after administering the drug. Meanwhile, levamisole is known to be an adulterant to cocaine and could be detected in addicts' plasma samples. Owing to its severe side effects, including agranulocytosis, which is lethal in many cases, detection and quantification of LVM in milk and plasma samples are of utmost importance. Therefore, a sensitive and selective analytical method is required for this purpose. This work develops a highly fluorescent probe obtained through the reaction between LVM and erythrosine-B in an acidic medium, where the produced ion pair complex has been measured at 553 nm after excitation at 528 nm. The proposed method provides linearity over the concentration range of 0.5-2.0 μg mL-1 for LVM, with a corresponding detection and quantitation limit of 0.5 and 0.3 μg mL-1. Full validation was performed, permitting the application of the suggested method to perform simple extraction steps. All the applied procedures followed the guidelines offered by green analytical chemistry, where the Green Analytical Procedure Index (GAPI) assessed the greenness of the proposed tool, and the yielded pictograms proved the eco-friendliness of the offered tool.

Polar metabolomics using trichloroacetic acid extraction and porous graphitic carbon stationary phase

IntroductionAccurately identifying and quantifying polar metabolites using untargeted metabolomics has proven challenging in comparison to mid to non-polar metabolites. Hydrophilic interaction chromatography and gas chromatography–mass spectrometry are predominantly used to target polar metabolites.ObjectivesThis study aims to demonstrate a simple one-step extraction combined with liquid chromatography–mass spectrometry (LC–MS) that reliably retains polar metabolites.MethodsThe method involves a MilliQ + 10% trichloroacetic acid extraction from 6 healthy individuals serum, combined with porous graphitic carbon liquid chromatography–mass spectrometry (LC–MS). The coefficient of variation (CV) assessed retention reliability of polar metabolites with logP as low as − 9. QreSS (Quantification, Retention, and System Suitability) internal standards determined the method's consistency and recovery efficiency.ResultsThe method demonstrated reliable retention (CV < 0.30) of polar metabolites within a logP range of − 9.1 to 5.6. QreSS internal standards confirmed consistent performance (CV < 0.16) and effective recovery (70–130%) of polar to mid-polar metabolites. Quality control dilution series demonstrated that ~ 80% of annotated metabolites could be accurately quantified (Pearson’s correlation coefficient > 0.80) within their concentration range. Repeatability was demonstrated through clustering of repeated extractions from a single sample.ConclusionThis LC–MS method is better suited to covering the polar segment of the metabolome than current methods, offering a reliable and efficient approach for accurate quantification of polar metabolites in untargeted metabolomics.

Determination of Nicotine in Juices, Soft and Energy Drinks collected from Libyan Local Markets Using UV–Visible Spectrophotometer

This study aims to determine the nicotine in juices, soft and energy drinks using a UV-Visible spectrophotometer. In the presented study, sixteen samples (four juices, seven soft drinks, and five energy drinks) are collected from local markets in El-Beida - Libya. A rapid, simple, and reliable extraction method is developed and validated for the determination of nicotine in the samples under study using spectrophotometric methods. The method is validated over a wide linear range of 1.62–81.06 µg/mL with correlation coefficients being consistently greater than 0.9999 by UV-Visible Spectrophotometer. The minimum nicotine level was observed in the juices samples, while the energy drinks samples showed the highest nicotine content. The spectrophotometric measurement indicates that the results of nicotine concentrations in juices samples are in the range of 0.3233 - 0.5238 µg/mL, whereas its concentrations in soft drinks samples are in the range of 0.7251 - 0.9949 µg/mL, and the concentrations in energy drinks samples are in the range of 0.8521 - 1.3471 µg/mL. The criteria considered for validation are linearity, the limit of detection, and the limit of quantitation. The nicotine contents in all the samples analyzed in our study were below the allowable limits set by the US Food and Drugs Administration.

A diverse proteome is present and enzymatically active in metabolite extracts

Metabolite extraction is the critical first-step in metabolomics experiments, where it is generally regarded to inactivate and remove proteins. Here, arising from efforts to improve extraction conditions for polar metabolomics, we discover a proteomic landscape of over 1000 proteins within metabolite extracts. This is a ubiquitous feature across several common extraction and sample types. By combining post-resuspension stable isotope addition and enzyme inhibitors, we demonstrate in-extract metabolite interconversions due to residual transaminase activity. We extend these findings with untargeted metabolomics where we observe extensive protein-mediated metabolite changes, including in-extract formation of glutamate dipeptide and depletion of total glutathione. Finally, we present a simple extraction workflow that integrates 3 kDa filtration for protein removal as a superior method for polar metabolomics. In this work, we uncover a previously unrecognized, protein-mediated source of observer effects in metabolomics experiments with broad-reaching implications across all research fields using metabolomics and molecular metabolism.

Routine method for the analysis of microplastics in natural and drinking water by pyrolysis coupled to gas chromatography-mass spectrometry

The presence of microplastics (MPs) in water intended for human consumption represents a growing concern due to their ubiquity in the aquatic environments and the potential adverse effects on human health. In this context, validated and standardized analytical methods are required to minimize uncertainties associated with the determination of MPs in water, especially during the drinking water treatment process. In this study, a simple water sampling and extraction procedure and analysis using pyrolysis with gas chromatography coupled to mass spectrometry (Py-GC–MS) was developed to determine 7 types of polymers in water. Quality parameters associated with the method were evaluated, including limits of detection (MDL) and quantitation (MQL), linearity, precision, accuracy, and extended uncertainty. The developed methodology was validated by participating in the EUROQCHARM interlaboratory exercise, and the Z-scores were within the acceptable range for 4 of the 5 polymers tested. Finally, MPs were determined in river water, reclaimed water, and drinking water from the urban area of Barcelona and total concentrations ranged from 11.3 µg/L to 77.1 µg/L. The proposed methodology allows for simple (direct filtration of 100–500 mL of water with a 13 mm glass fiber filter), quantitative (µg/L), and rapid (with a total analysis time of 20 min per sample, including both pyrolysis and GC–MS) analysis of MPs in water intended for drinking.