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Wyniki wyszukiwania dla: extraction techniques
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Dispersive Micro‐Solid Phase Extraction of Selected Metals in Water and Food Samples Followed by ICP‐OES Analysis: Method Development, Analysis of Real Samples and Greenness Evaluation
PublikacjaMultiwalled carbon nanotubes (MWCNTs) are well-known adsorbents because of their high surface area, layered and hollow architecture, hydrophobicity, and multiple and easily accessible adsorption sites. In this study, MWCNTs were used for dispersive micro-solid-phase extraction of various metal chelates in environmental and food samples. Different parameters such as concentration of the chelating reagent, the sorbent dosage, the...
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Membrane-SPME the best 'green' sample preparation technique for the gas chromatographic determination polar organic pollutants in polar media
PublikacjaOne of the most popular technique for sample preparation, which fulfill requirements of green analytical chemistry, is solid phase microextraction (SPME). Because of the undoubted advantages of SPME technique, solvent-free character of the extraction process and the enormous potential in analytical practice, a series of studies has been undertaken to develop new technical solutions, where improving the sensitivity and the extraction...
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Ultrasound assisted solvent extraction of porous membrane-packed samples followed by liquid chromatography-tandem mass spectrometry for determination of BADGE, BFDGE and their derivatives in packed vegetables
PublikacjaThe problem of the presence of trace organic pollutants in food is of growing importance due to increasing awareness about their impact on newborns, infants and adults of reproductive age. Despite the fact that packaged food products offer many advantages, packaging can be a source of contamination for stored food. Thus, monitoring such pollution in food is of high importance. In this work, a novel methodology based on the solvent...
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Dispersive liquid-liquid microextraction combined with gas chromatography–mass spectrometry for in situ determination of biogenic amines in meat: Estimation of meat's freshness
PublikacjaA dispersive liquid-liquid microextraction (DLLME) gas chromatography–mass spectrometry (GC–MS) technique was developed for the determination of selected biogenic amines (BAs) in samples of poultry, pork and beef. Prior to the extraction process, an appropriate volume of sodium hydroxide solution was added to each of the portioned samples. Next, samples were homogenized, centrifuged and finally sonicated at an increased temperature....
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Determination of antifreeze substances in the airport runoff waters by solid-phase microextraction and gas chromatography–mass spectrometry method
PublikacjaA new method has been developed for the determination of antifreeze agents such as ethylene glycol (EG), propylene glycol (PG), and diethylene glycol (DEG) in the samples of airport runoff water. The method is based on headspace solid–phase microextraction (HS–SPME) of target analytes, which is coupled with gas chromatography–mass spectrometry (GC–MS). Until now, there was a lack of appropriate methodology for collecting reliable...
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Development of a vortex-assisted switchable-hydrophilicity solvent-based liquid phase microextraction for fast and reliable extraction of Zn (II), Fe (II), Pb (II), and Cd (II) from various baby food products
PublikacjaThis manuscript describes the development of a novel liquid phase microextraction (LPME) method for the extraction and determination of Zn (II), Fe (II), Pb (II), and Cd (II) in various infant/baby food and supplements products. The method is based on vortex-assisted extraction combined with a switchable-hydrophilicity solvent (SHS) sample preparation. The SHS, which undergoes reversible phase changes triggered by pH change, enables...
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Method for the simultaneous determination of monoaromatic and polycyclic aromatic hydrocarbons in industrial effluents using dispersive liquid-liquid microextraction with GC-MS
PublikacjaWe present a new method for simultaneous determination of 22 monoaromatic and polycyclic aromatic hydrocarbons in postoxidative effluents from the production of petroleum bitumen using dispersive liquid-liquid microextraction coupled to gas chromatography and mass spectrometry. The eight extraction parameters including the type and volume of extraction and disperser solvent, pH, salting out effect, extraction and centrifugation...
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SURFACTANTS IN KLODNICA RIVER (KATOWICE, POLAND). PART II. QUATERNARY AMMONIUM COMPOUNDS
PublikacjaThe paper presents methods of determination of analytes of the cation group (alkyl benzyl dimethyl ammonium (BDDA-C12-C16), alkyl trimethyl ammonium (TMA), hexadecyl piridinium (HP)) in surface water and bottom sediment samples. In the sample preparation phase the solid phase extraction (SPE) or accelerated solvent extraction/ultrasound assisted extraction (ASE/UAE)-SPE technique was used and in the identification phase and quantitative...
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Application of multicriteria decision analysis in solvent type optimization for chlorophenols determination with a dispersive liquid–liquid microextraction
PublikacjaThis study presents a novel support tool for the optimization and development of analytical methods. The tool is based on multi-criteria decision analysis (MCDA), namely the Technique for Order of Preference by Similarity to the Ideal Solution (TOPSIS), that allows users to rank possible solutions according to their requirements. In this study, we performed rankings of pairs of eight extraction and three dispersive solvents used...
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Novel materials and approaches for solid-phase (micro) extraction in LC-MS-based metabolomics
PublikacjaMetabolomics offers a unique approach to study biological systems. Liquid chromatography coupled to mass spectrometry serves as a powerful analytical tool to analyze complex mixtures of metabolites. However, successful metabolomic analysis relies on sample preparation. While untargeted analysis traditionally favors nonselective procedures like liquid-liquid extraction (LLE), these methods can compromise analytical performance due...
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Review of Shoreline Extraction Methods from Aerial Laser Scanning
PublikacjaAutonomous technologies are increasingly used in various areas of science. The use of unmanned vehicles for hydrographic surveys in shallow coastal areas requires accurate estimation of shoreline position. This is a nontrivial task, which can be performed using a wide range of sensors and methods. The aim of the publication is to review shoreline extraction methods based solely on data from aerial laser scanning (ALS). This narrative...
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Remote Health Monitoring of Wind Turbines Employing Vibroacoustic Transducers and Autoencoders
PublikacjaImplementation of remote monitoring technology for real wind turbine structures designed to detect potential sources of failure is described. An innovative multi-axis contactless acoustic sensor measuring acoustic intensity as well as previously known accelerometers were used for this purpose. Signal processing methods were proposed, including feature extraction and data analysis. Two strategies were examined: Mel Frequency Cepstral...
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Green products from herbal medicine wastes by subcritical water treatment
PublikacjaHerbal medicine wastes (HMWs) are byproducts of medicine factories, which are mainly landfilled for their environmental problems. Only bearing in mind the contamination and concerns caused by the COVID-19 pandemic and environmental emissions, the worth of herbal medicine wastes management and conversion to green products can be understood. In this work, subcritical water treatment was carried out batch-wise in a stainless tube...
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Silicon’s Influence on Polyphenol and Flavonoid Profiles in Pea (Pisum sativum L.) under Cadmium Exposure in Hydroponics: A Study of Metabolomics, Extraction Efficacy, and Antimicrobial Properties of Extracts
PublikacjaThe current study aimed to investigate the impact of silicon (Si) supplementation in the form of Na2SiO3 on the metabolome of peas under normal conditions and following exposure to cadmium (Cd) stress. Si is known for its ability to enhance stress tolerance in various plant species, including the mitigation of heavy metal toxicity. Cd, a significant contaminant, poses risks to...
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Quality control of cheese samples for the presence of natamycin preservative – A natural deep eutectic solvent (NADES) based extraction coupled with HPLC
PublikacjaA new protocol for the determination of natamycin – an antifungal agent used as a food preservative - in cheese samples – is described. This new method is based on a natural deep eutectic solvent (NADES) green extraction procedure. High-performance liquid chromatography (HPLC) was used for detection and quantification. NADESs with different molar ratios were evaluated for efficient and selective extraction. NADES made of thymol...
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Application of response surface methodology to optimize solid-phase microextraction procedure for chromatographic determination of aroma-active monoterpenes in berries
PublikacjaMost of scientific papers concern the qualitative or semi-quantitative analysis of aroma-active terpenes in liquid food matrices. Therefore, the procedure based on solid-phase microextraction and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for determination of monoterpenes in fresh berries was developed. The optimal extraction conditions using divinylbenzene-carboxen-polydimethylsiloxane fiber...
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Multi-residue method for the determination of 16 recently used pesticides from various chemical groups in aqueous samples by using DI - SPME coupled with GC-MS
PublikacjaA simple and solvent-free multi-residue method has been optimized to determine 16 currently used pesticides from different chemical groups in aqueous samples. The extraction of analytes was carried out with direct immersion solid-phase microextraction (DI-SPME) and for the identification and quantitative determination gas chromatography coupled with mass spectrometry (GC-MS) was applied. Two commonly used adsorbent coatings have...
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Application of deep eutectic solvents (DES) in analytical chemistry
PublikacjaRecent years have been associated with efforts to reduce the impact on the natural environment. A greener approach has been introduced in various areas of science, including analytical chemistry. One of the basic procedures for preparing a sample for analysis is its extraction. Traditional methods involve the use of large amounts of organic compounds, often toxic, with an unfavorable impact on the environment. A representative...
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Chip suction system in circular sawing machine: empirical research and computational fluid dynamics numerical simulations
PublikacjaThe experimental analysis of the wood chip removing system during its redesigning in the existing sliding table circular saw and computational fluid dynamic (CFD) numerical simulations of the air flow process is presented in the paper. The attention was focused on the extraction hood and the bottom shelter of the actual existing system. The main aim was to perform experimental research on the pressure distribution inside the...
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New procedure for the control of the treatment of industrial effluents to remove volatile organosulfur compounds
PublikacjaWe present a new procedure for the determination of volatile organosulfur compounds in samples of industrial effluents using dispersive liquid–liquid microextraction and gas chromatography with flame photometric detection. Initially, the extraction parameters were optimized. These included: type and volume of extraction solvent, volume of disperser solvent, salting out effect, pH, time and speed of centrifugation as well as extraction...
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Effect of Laminar Pulsatile Fluid Flow on Separation of Volatile Organic Compounds from Aqueous Solution by a Hollow Fiber Membrane-Based Process
PublikacjaIn this study, a laminar pulsatile fluid flow was used for the separation of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) from aqueous solutions. Polyether sulfone hollow fiber membrane has been applied to this process. The effects of BTEX concentration, and feed and extraction flow rates were examined. It was found that the application of the pulsatile fluid flow with...
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The role of water in deep eutectic solvent-base extraction
PublikacjaDeep eutectic solvents (DESs) are currently being used in different sectors, such as electrochemistry, electrodeposition, organic synthesis, nanoparticle preparation, bioactive compound separation, etc. Their use in analytical chemistry has only recently begun to expand. Despite the publication of a sufficient number of DES-based analytical extraction procedures, some details, such as interaction of DESwith the sample and target...
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Comparison of two methods of sound extraction from guitar string video recordings
PublikacjaA comparison of two sound extraction methods from guitar string video recordings is presented in the paper. A brief overview of highframe rate camera technology and possible applications are included. The method using the image analysis from two such cameras is presented. The cameras are placed at the angle of 90 degrees for recording the image in three planes. The results achieved...
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An energetic analysis of a gas turbine with regenerative heating using turbine extraction at intermediate pressure - Brayton cycle advanced according to Szewalski's idea
PublikacjaIn this paper, a modification of a simple gas turbine into the Brayton cycle with regenerative heating, using turbine extraction at intermediate pressure, is presented. The main concept of the retrofitting is based on the transfer of heat from the turbine exhaust gases to the air entering the combustion chamber. The extracted gas transfers heat to air via the divided regenerative heat exchanger and after that is compressed and...
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Investigation of use of hydrophilic/hydrophobic NADESs for selective extraction of As(III) and Sb(III) ions in vegetable samples: Air assisted liquid phase microextraction and chemometric optimization
PublikacjaIn this paper, a green, cost-effective sample preparation method based on air assisted liquid phase microextraction (AA-LPME) was developed for the simultaneous extraction of As(III) and Sb(III) ions from vegetable samples using hydrophilic/hydrophobic natural deep eutectic solvents (NADESs). Central composite design was used for the optimization of extraction factors including NADES volume, extraction cycle, pH, and curcumin concentration....
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Combination of homogeneous liquid–liquid extraction and vortex assisted dispersive liquid–liquid microextraction for the extraction and analysis of ochratoxin A in dried fruit samples: Central composite design optimization
PublikacjaThis paper presents a new analytical procedure based on combination of homogeneous liquid–liquid extraction (HLLE) and vortex-assisted dispersive liquid–liquid microextraction (VA-DLLME) for the accurate and reliable determination of ochratoxin A (OTA) in dried fruit samples. To enable selective extraction of the OTA, six hydrophobic deep eutectic solvents (hDESs) were prepared and tested as extraction solvents. Optimization of...
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Characterization of novel trehalose synthase from Deinococcus geothermalis.
PublikacjaThe method of trehalose extraction from yeast or othernatural sources is unsuitable for industrial production becauseof its low yield and high cost. Thus, the trehalose synthesizingenzyme systems that originated from a few microorganisms have been investigated.
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Development and validation of a method for the simultaneous analysis of fatty acid ethyl esters, ethyl sulfate and ethyl glucuronide in neonatal meconium: application in two cases of alcohol consumption during pregnancy
PublikacjaAlcohol consumption during pregnancy constitutes one of the leading preventable causes of birth defects and neurodevelopmental disorders in the exposed children. Fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG) and ethyl sulfate (EtS) have been studied as potential biomarkers of alcohol consumption. However, most analytical approaches proposed for their analysis in meconium samples consist of separated extraction procedures...
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Shoreline Extraction Based on LiDAR Data Obtained Using an USV
PublikacjaThis article explores the use of Light Detection And Ranging (LiDAR) derived point clouds to extract the shoreline of the Lake Kłodno (Poland), based on their geometry properties. The data collection was performed using the Velodyne VLP‐16 laser scanner, which was mounted on the HydroDron Unmanned Surface Vehicle (USV). A modified version of the shoreline extraction method proposed by Xu et al. was employed, comprising of the following...
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Systematic Literature Review for Emotion Recognition from EEG Signals
PublikacjaResearchers have recently become increasingly interested in recognizing emotions from electroencephalogram (EEG) signals and many studies utilizing different approaches have been conducted in this field. For the purposes of this work, we performed a systematic literature review including over 40 articles in order to identify the best set of methods for the emotion recognition problem. Our work collects information about the most...
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Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Using Deep Eutectic Solvents (DESs) for Neutral Red Dye Spectrophotometric Determination
PublikacjaDeep eutectic solvents (DES), which have low toxicity and are low cost, biodegradable, and easily synthesized, were used for the extraction of neutral red (NR) dye before its spectrophotometric analysis. DES, containing choline chloride as a hydrogen bond acceptor and phenol as a hydrogen bond donor with a molar ratio of 1:2, was used for the extraction of NR dye from aqueous media. The possible interaction of different DESs with...
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Systematic Literature Review for Emotion Recognition from EEG Signals
PublikacjaResearchers have recently become increasingly interested in recognizing emotions from electroencephalogram (EEG) signals and many studies utilizing different approaches have been conducted in this field. For the purposes of this work, we performed a systematic literature review including over 40 articles in order to identify the best set of methods for the emotion recognition problem. Our work collects information about the most...
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Rapid Characterization of the Human Breast Milk Lipidome Using a Solid-Phase Microextraction and Liquid Chromatography-Mass Spectrometry-Based Approach.
PublikacjaHuman breast milk (HBM) is a biofluid consisting of various biomolecules such as proteins, lipids, carbohydrates, minerals and bioactive substances. Due to its unique and complex composition, HBM provides not only nutritional components required for the growth of the infant, but also additional protection against infections. Global insight into the composition of HBM is crucial to understanding the health benefits infants receive...
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Music Information Retrieval – Soft Computing versus Statistics . Wyszukiwanie informacji muzycznej - algorytmy uczące versus metody statystyczne
PublikacjaMusic Information Retrieval (MIR) is an interdisciplinary research area that covers automated extraction of information from audio signals, music databases and services enabling the indexed information searching. In the early stages the primary focus of MIR was on music information through Query-by-Humming (QBH) applications, i.e. on identifying a piece of music by singing (singing/whistling), while more advanced implementations...
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Sensitive method for determination of benzoic acid in beverages and food samples using air–assisted hydrophobic deep eutectic solvent-based dispersive liquid-liquid microextraction
PublikacjaA simple, reliable and rapid air–assisted hydrophobic deep eutectic solvent-based dispersive liquid–liquid microextraction (AA-HDES-DLLME) was developed for analysis of benzoic acid in various beverages and food samples. The final determination stage was performed via UV–visible spectrophotometry. The key parameters (extraction time, HDES type and volume, dispersant volume, pH and sample volume) of the AA-HDES-DLLME method were...
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Polychlorinated biphenyls (PCBs) and polychlorodibenzo-p-dioxins (PCDDs) determination in disposable baby diapers with the application of natural deep eutectic solvent
PublikacjaIn this work a new method involving solvent extraction of porous membrane-packed solid samples (SE-PMSS) coupled to gas chromatography-mass spectrometry (GC–MS) has been developed for the determination of six polychlorinated biphenyls (PCBs) and five polychlorodibenzo-p-dioxines (PCDDs) in disposable baby diapers. In that aim, a terpenoid-based natural deep eutectic solvent (NADES) composed of carvone and camphor in a 1:1 M ratio...
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Deep eutectic solvents based assay for extraction and determination of zinc in fish and eel samples using FAAS
PublikacjaA new assay based on effective (high recovery) extraction by means of deep eutectic solvents (DESs) was developed for ppb level determination of zinc in fishes and eel samples. Choline chloride and Phenol in a 1:2 M ratio was selected as optimal DES-based extraction solvent. 8-Hydroxy quinoline was used as a chelating agent for zinc ions. The optimized conditions were found at pH value of 8, ligand concentration of 10 mg/L, THF...
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Determination of phenylbutazone, sulfamethazine, carbendazim and linuron using a novel pine bark biosorbent for solid-phase extraction (SPE) with high-performance liquid chromatography (HPLC)
PublikacjaThe paper presents a novel pine bark based biosorbent for solid-phase extraction (SPE). The morphology and composition of the pine bark were characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The biosorbent was used for the preparation of wastewater for the determination of phenylbutazone, sulfamethazine, carbendazim, and linuron by high performance liquid chromatography with...
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Natural sweeteners: Sources, extraction and current uses in foods and food industries
PublikacjaFood producers have leaned towards alternative natural and synthetic sweeteners in food formulations to satisfy market demands. Even so, several synthetic sweeteners (e.g., aspartame, saccharin, sucralose) are becoming less popular due to health-related concerns, lower nutritional values, and controversies around their safety. Conversely, natural sweeteners confer favourable customer perceptions due to their association to a healthier...
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Application of ultrasound-assisted solvent extraction of porous membrane packed liquid samples for polyphenols determination in wine samples
PublikacjaPolyphenols play a crucial role in a proper human health maintenance as well as their presence very often correspond to the quality assessment of producs like wine. Thus, their monitoring is of high interest. However, as they occur in a complex matrices their extraction is very often necessary prior the analysis. Herein, a new ultrasound-assisted solvent extraction of porous membrane packed liquid sample technique has been optimized...
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Discovering patterns of Web Page Visits from Associaton Rules Viewpoint
PublikacjaThe popularity of the Internet results from the almost unlimited resources of information stored in it. At the same time, Internet portals have become a widespread source of information and note very large number of visits. The list of web pages opened by users is stored in web servers' log files. Extraction of knowledge on the navigation paths of users has become carefully analyzed problem. Currently, there are a number of algorithms...
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Quechers sample preparation method variants for analysis of pesticide residues in fruits and vegetables
PublikacjaThis article describes the comparison of different versions of an easy, rapid and low-cost sample preparation approach for the determination of pesticide residues in fruits and vegetables by concurrent use of gas and liquid chromatography coupled to MS or ECD for detection. The sample preparation approach is known as QuEChERS, which stands for quick, easy, cheap, effective, rugged and safe. It is a combination of liquid-liquid...
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Modern trends in solid phase extraction: New sorbent media
PublikacjaBased on the recently published literature, this review provides an update of the most important features and application of formats and devices employed in solid phase extraction (SPE). Special attention was paid on new trapping media proposed in SPE prior the chromatography analysis, based on the use of nanostructured materials, including carbon nanomaterials, electrospun nanofibers, dendrimes and magnetic nanoparticles, molecular...
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Determination of fuel combustion product in airport runoff water samples using liquid–liquid extraction with gas chromatography–spectrometry
PublikacjaDetermination of xenobiotics in samples of airport runoff water is both a complex and indispensable task due to an increasing threat resulting from the activities of numerous airports. The aim of this study was to develop, optimize, and validate a procedure based on liquid–liquid extraction (LLE) coupled with gas chromatography–mass spectrometry (GC–MS) for the determination of polycyclic aromatic hydrocarbons (PAHs). So far, no...
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Novel fast analytical method for indirect determination of MCPD fatty acid esters in edible oils and fats based on simultaneous extraction and derivatization
PublikacjaA novel method for indirect determination of MCPD esters levels in lipid samples has been developed. The method is based on combination of extraction and derivatisation in the same sample preparation step. It is achieved by the application of diethyl ether as extraction solvent for isolation of released from esterified forms analytes from water phase and dilution solvent for solid PBA – derivatisation agent. It is a noteworthy...
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Optimization of vortex-assisted supramolecular solvent-based liquid liquid microextraction for the determination of mercury in real water and food samples
PublikacjaA novel method was developed for sample preparation for spectrophotometric determination of Hg(II) in water and food samples. The method was based on vortex-assisted supramolecular solvent-assisted liquid-liquid microextraction (VA-SUPRASs-LLME). Analytical parameters such as pH, chelating agent, solvent type and volume, vortex time and salting out effect were optimized. Surface and normal probability plots were drawn for the variables...
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The presence of polycyclic aromatic hydrocarbons in disposable baby diapers: A facile determination method via salting-out assisted liquid-liquid extraction coupled with gas chromatography-mass spectrometry
PublikacjaIn this paper we demonstrate the development of the extraction procedure of polycyclic aromatic hy- drocarbons from baby diapers along with their quantification by gas chromatography-mass spectrometry. Apart from covering plastic foil, disposable baby diapers contain sorbents intended to absorb urine and feces. A hygroscopic, adsorptive, and tough-to-homogenize fibrous sorbent, represents an analytical chal- lenge to analytical...
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Analyzing the Effectiveness of the Brain–Computer Interface for Task Discerning Based on Machine Learning
PublikacjaThe aim of the study is to compare electroencephalographic (EEG) signal feature extraction methods in the context of the effectiveness of the classification of brain activities. For classification, electroencephalographic signals were obtained using an EEG device from 17 subjects in three mental states (relaxation, excitation, and solving logical task). Blind source separation employing independent component analysis (ICA) was...
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Liquid–phase microextraction: A review of reviews
PublikacjaSample preparation is an important step in chemical analysis. It is generally done to deal with problems associated with the nature of the matrix, low analyte concentrations in real samples or analyte features incompatible with the instrumentation. Classical methods of extraction consume large volumes of hazardous solvents and other reagents and are not in line with the recent emergence of green analytical chemistry. Liquid-phase...
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Role of Silicon in Counteracting Cadmium Stress in Pea Plants (Pisum sativum L.): Insights Into Cadmium Binding Mechanisms and Pectin Methylesterase Activity
PublikacjaPurpose: The aim of this study was to investigate the role of silicon (Si) in counteracting a cadmium (Cd) stress to pea plants (Pisum sativum L.) and to identify the mechanism by which Cd is bound within pea roots. Methods: These goals were achieved through (i) a histochemical study of Cd localization in pea roots, (ii) spectrophotometric determination of pectin content and the activity...