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Search results for: COMPLEX SAMPLES
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Molecularly imprinted polymers based on deep eutectic solvents as a greenest materials for selective extraction of emerging contaminants from complex samples
PublicationSome of the reagents applied in the synthesis of molecularly imprinted polymers (MIPs) may impact on health and the environment. Thus, a new generation of promising green chemicals are nowadays introduced and investigated, including deep eutectic solvents (DESs). DESs seems to be a reasonable choice as they are characterized as non-toxic, low cost, easy to prepare and biodegradable chemicals. This review presents the information...
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New achievements in the field of extraction of trace analytes from samples characterized by complex composition of the matrix
PublicationWithout any doubt, the monitoring of compounds present in samples at trace or ultra-trace level usually requires a preliminary step of isolation and/or enrichment of analytes due to the fact that majority of analytical techniques are not sensitive enough for direct determination of trace compounds. On the other hand, sample preparation is considered as crucial part of whole analytical procedures, in particular in samples characterized...
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Main complications connected with detection, identification and determination of trace organic constituents in complex matrix samples
PublicationIt is well known that some problems with the determination of organic analytes at trace level can occur. This issue is connected with contamination during each stage of the analytical procedure from sampling to sample preparation up to chromatographic analysis, which often leads to false-positive or overestimated results. Another problem associated with determination of analytes occurs at trace- and ultra-trace level is a background...
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Weronika Hewelt-Belka dr hab. inż.
PeopleI am specializing in analytical chemistry with a primary focus on lipidomics and metabolomics. My research centers on the development and application of cutting-edge analytical techniques, particularly high-performance liquid chromatography coupled with mass spectrometry (LC-MS), to explore complex biological matrices and deepen our understanding of human metabolism and health. A significant part of my work is dedicated to studying...
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Application of ultrasound-assisted solvent extraction of porous membrane packed liquid samples for polyphenols determination in wine samples
PublicationPolyphenols 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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Self-Adaptive Mesh Generator for Global Complex Roots and Poles Finding Algorithm
PublicationIn any global method of searching for roots and poles, increasing the number of samples increases the chances of finding them precisely in a given area. However, the global complex roots and poles finding algorithm (GRPF) (as one of the few) has direct control over the accuracy of the results. In addition, this algorithm has a simple condition for finding all roots and poles in a given area: it only requires a sufficiently dense...
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PBDEs in environmental samples: Sampling and analysis
PublicationThe paper reviews the subject literature concerning analytical procedures routinely sed for monitoring polybrominated diphenyl ethers (PBDE) in environmental samples. It describes and summarizes subsequent stages of analytical procedure including sample collection and preparation, extraction, clean-up and final determination. Different approaches with their advantages and limitations are presented. Special attention is drawn to...
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Isotope-labeled substances in analysis of persistent organicpollutants in environmental samples
PublicationUltratrace analysis of persistent organic pollutants (POPs) in environmental samples requires very sophisticated methods for both sample preparation and instrumental analysis. The complex matrix requires a multi-stage procedure. Each stage is a potential source of error, as a consequence of which the final result of analysis could be a source of misinformation rather than information. The individual stages and the procedure as...
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Determination of fuel combustion product in airport runoff water samples using liquid–liquid extraction with gas chromatography–spectrometry
PublicationDetermination 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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The estrogenicity of wastewater samples.
Open Research DataThe principle of operation of the kit is based on the fact that the tested sample with endocrine activity (containing compounds capable of binding to the human estrogen receptor α, hERα) releases the fluorescently labeled ligand (FluormoneTM ES2) from the receptor-ligand complex, which results in a reduction of the polarization value fluorescence. The...
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Multimodal Particle Swarm Optimization with Phase Analysis to Solve Complex Equations of Electromagnetic Analysis
PublicationIn this paper, a new meta-heuristic method of finding roots and poles of a complex function of a complex variable is presented. The algorithm combines an efficient space exploration provided by the particle swarm optimization (PSO) and the classification of root and pole occurrences based on the phase analysis of the complex function. The method initially generates two uniformly distributed populations of particles on the complex...
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Application of magnetic nanoparticles for magnetic solid-phase extraction in preparing biological, environmental and food samples
PublicationThe need to obtain meaningful results as the basis for determining the content of trace amounts of analytes has become the driving force behind the development of modern analytical techniques, including sample-preparation techniques, such as solid-phase extraction (SPE). Recently, great interest was aroused in the use of magnetic nanoparticles (MNPs) in SPE. These materials exhibit high selectivity, and, in small amounts, can provide...
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Ultrasound-assisted solvent extraction of porous membrane packed solid samples: A new approach for extraction of target analytes from solid samples
PublicationFor the first time, a porous membrane-based method is proposed for the extraction of target analytes directly from the solid samples. This method involves the packing of solid sample inside a porous polypropylene membrane sheet whose edges are heat-sealed to fabricate a bag. This bag is immersed in a suitable solvent and the analytes are extracted by the application of ultrasound energy. The various factors that affect the extraction...
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Analytical and bioanalytical problems associated with the toxicity of elemental sulfur in the environment
PublicationWe summarize the state of knowledge on the toxicity and the bioavailability of elemental sulfur. We also present: analytical methods used to determine the elemental sulfur content of samples with complex matrices; and, problems and difficulties encountered while using biotests for samples containing elemental sulfur.
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New Trends in Sample Preparation Techniques for the Analysis of the Residues of Pharmaceuticals in Environmental Samples
PublicationPharmaceutical residues in the environment is a field of special interest due to the adverse effects to either human health or aquatic and soil environment. Pharmaceuticals have been already detected in underground, surface and wastewaters, soils, manure and sediments. The growing awareness of environmental pollution arising from human activity forces the need for their comprehensive determination. Environmental samples are complex...
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Review of the determination of modern used pesticides in water samples
PublicationThe increasingly widespread application of pesticides causes that larger amounts of them are entering the environment. Their presence in sources of drinking water, essential to life, is a particular danger. For these reasons it is important to monitor and analyse pesticide residues in the environment. The analysis of environmental samples for the presence of pesticides is very difficult. Firstly, the processes involved in sample...
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INFLUENCE OF BISMUTH CONTENT ON COMPLEX IMMITTANCE CHARACTERISTICS OF PRESSURELESS SINTERED BiNbO4 CERAMICS
PublicationGoal of the present research was to study immittance properties of BiNbO4 ceramics fabricated by the solid state reaction route followed by pressureless sintering. Four sets of samples were examined, namely the one fabricated from the stoichiometric mixture of oxides, viz. Bi2O3 and Nb2O5 as well as the ones with an excess of 3%, 5% and 10% by mole of Bi2O3. The immittance properties were studied by impedance spectroscopy. Measurements...
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Estimation of Broadband Complex Permeability Using SIW Cavity-Based Multimodal Approach
PublicationIn this article, an attractive multimodal substrate integrated waveguide (SIW) based methodology is presented for the characterization of magnetic materials in the broadband microwave frequency. The proposed approach employs a modified feed under-coupled SIW cavity instead of conventional feed over-coupled multiple SIW cavities; it uses the modified closedform expression, developed from the first principle to consider the effect...
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Microextraction Techniques Used in the Procedures for Determining Organomercury and Organotin Compounds in Environmental Samples
PublicationDue to human activities, the concentrations of organometallic compounds in all parts of the environment have increased in recent decades. The toxicity and some biochemical properties of mercury and tin present in the environment depend on the concentration and chemical form of these two elements. The ever-increasing demand for determining compounds at very low concentration levels in samples with complex matrices requires...
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Uncertainty of antioxidant profiling in complex mixtures using liquid chromatography involving post-column derivatisation
PublicationThe main goal of this paper is to discuss the problems associated with antioxidant profiling in complex samples using a high-throughput HPLC system coupled with post-column derivatisation reactor. Based on the experimental data reported in the literature, we demonstrated that improper optimisation of temperature and/or pH assay conditions performed using an on-line derivatisation reactor may substantially change the antioxidant...
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Hydrophobic deep eutectic solvents as “green” extraction media for polycyclic aromatic hydrocarbons in aqueous samples
PublicationThe paper presents novel nonionic and hydrophobic deep eutectic solvents which were synthesized from natural compounds, i.e., thymol, ±camphor, decanoic and 10-undecylenic acids. Fundamental physicochemical properties of the synthesized deep eutectic solvents were determined, followed by their application as extractants in ultrasound-assisted dispersive liquid-liquid microextraction to isolate and enrich polycyclic aromatic hydrocarbons...
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Green Aspects of Miniaturized Sample Preparation Techniques
PublicationCorrect monitoring and control of the state of the environment and scientific research on the subject of environmental protection often require that determinations of compounds present at very low concentrations be made in samples characterized by a matrix of complex composition (e.g., biological samples, water and soil samples). Moreover, due to the limited number of analytical techniques which are sufficiently sensitive to conduct...
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Modern solutions in the field of microextraction using liquid as a medium of extraction
PublicationThe monitoring of compounds present in samples at trace/ultra-trace level usually requires a preliminary step of isolation and/or enrichment of analytes. Against, sample preparation is considered as crucial part of whole analytical procedures, in particular in samples characterized by complex matrices composition. Several new miniaturized extraction techniques is introduced and extensively applied to different type of samples....
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Genetic and biochemical characterization of yeasts isolated from Antarctic soil samples
PublicationThe Polish Arctowski Station is situated in the maritime Antarctic on the western shore ot' Admiralty Bay and encompasses terrestrial habitats which are not perma-nently covered by ice, in contrast to morę than 90% of the island's surface area. Over the past several decades, stud-ies exploring the soils of those habitats have revealed a considerable diversity of bacteria, filamentous fungi, and, to a lesser extent, yeasts; however,...
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New procedure for the examination of the degradation of volatile organonitrogen compounds during the treatment of industrial effluents
PublicationWe present a new procedure for the determination of 32 volatile organonitrogen compounds in samples of industrial effluents with a complex matrix. The procedure, based on dispersive liquid–liquid microex-traction followed by gas chromatography with nitrogen-phosphorus and mass spectrometric detection, wasoptimized and validated. Optimization of the extraction included the type of extraction and disperser sol-vent, disperser solvent...
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State of the art in sample preparation for human breast milk metabolomics—merits and limitations
PublicationHuman breast milk (HBM) contains metabolites that are diverse in chemical structure and concentration. These metabolites range from high-abundance to low-abundance compounds and from polar to nonpolar. This complex nature of HBM makes HBM samples difficult to analyze, especially in global metabolomic studies for the determination and characterization of complete sets of metabolites. In this review, the state of the art in sample...
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NON-LOCAL VOLUMETRIC APPROACH TO ANALYSIS DEFECT'S SHAPE INFLUENCE ON SPECIMENS DURABILITY SUBJECTED TO BENDING AND TORSION
PublicationThe influence of defect features on fatigue behaviour is a complex trivial issue. Although the important advances over the last decades, the dialectical relationship between the defect orientation and durability is not clearly understood. The paper aims at studying the influence of the orientation of elliptical defects on the durability of samples made of C45 steel. Three types of samples with elliptical defects were subjected...
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Impact of Volcanic Eruptions on the Occurrence of PAHs Compounds in the Aquatic Ecosystem of the Southern Part of West Spitsbergen (Hornsund Fjord, Svalbard)
PublicationThe paper presents changes in concentration levels of dioxin-like compounds that can be observed over the course of four study seasons in water samples collected from the Arctic watershed of Svalbard. The conducted analysis involved anthropogenic and natural factors that may affect the concentration of PAHs in the study samples of water. An attempt is made to indicate the emission source of the compounds being deposited and to...
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Characterization of GM3 Gangliosides in Human Milk throughout Lactation: Insights from the Analysis with the Use of Reversed-Phase Liquid Chromatography Coupled to Quadrupole Time-Of-Flight Mass Spectrometry
PublicationGangliosides are complex lipids found in human milk that play important structural and biological functions. In this study, we utilized reversed-phase liquid chromatography coupled to quadrupole time-of-flight mass spectrometry to evaluate the molecular distribution of GM3 in human milk samples collected at distinct lactation stages, ranging from colostrum to advanced lactation samples. Throughout lactation, GM3 d40:1 emerged as...
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Determination of volatile organic compounds using solventless sample preparation techniques and gas chromatography
PublicationIn this paper the latest advances in the determination of volatile organic compounds using solvent-free extraction techniques in the sample preparation step are presented. A paper is focus mainly on one of the most popular sample preparation technique: solid-phase microextraction technique (SPME) combined with different detection systems and its applications to sampling of VOCs from the samples with different matrices. This paper...
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Main strategies, analytical trends and challenges in LC-MS and ambient mass spectrometry-based metabolomics
PublicationA plethora of analytical LC-MS-based methods have been successfully applied to analyses of complex samples of various origin for metabolomics investigations. Over the last ten years, the substantial evolution of ambient mass spectrometry (AMS) techniques has highlighted their tremendous potential in metabolomic studies due to the minimal sample pretreatment requirement and the ability to analyse samples in their native state. This...
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Preconcentration and Analytical Methods for Determination of Methyl Tert-Butyl Ether and Other Fuel Oxygenates and Their Degradation Products in Environment: A Review
PublicationFuel oxygenates (FOs) are mainly ethers or alcohols which are added to gasoline either to boost the octane number or to make the fuel burning process more "cleaner" with increasing the oxygen content, or to obtain a combination of both effects. FOs are water soluble with high mobility in the environment which presence even at very low concentrations lower the quality of water making it unsafe or unpleasant due to their objectionable...
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Online sound restoration system for digital library applications
PublicationAudio signal processing algorithms were introduced to the new online non-commercial service for audio restoration intended to enhance the content of digitized audio repositories. Missing or distorted audio samples are predicted using neural networks and a specific implementation of the Jannsen interpolation method based on the autoregressive model (AR) combined with the iterative restoring of missing signal samples. Since the distortion...
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Development of an orbital shaker-assisted fatty acid-based switchable solvent microextraction procedure for rapid and green extraction of amoxicillin from complex matrices: Central composite design
PublicationIn this study, a cheap, fast and simple orbital shaker-assisted fatty acid-based switchable solvent microextraction (OS-FASS-ME) procedure was developed for the extraction of amoxicillin (AMOX) in dairy products, pharmaceutical samples and wastewater prior to its spectrophotometric analysis. Fatty acid-based switchable solvents were investigated for extracting AMOX. The key factors of the OS-FASS-ME procedure were optimized using...
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Organotin Compounds: Environmental Fate and Analytics
PublicationFor more than 50 years, organotin compounds have been used in almost all sectors of industry. As a consequence, specific environmental compartments are affected by the emission of these xenobiotics. The emissions of organotin compounds into the environment from paints used in the shipbuilding industry for ship hull coating, and from the plant protection products are particularly significant.In 2001, the IMO introduced a global...
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Engineering boron and nitrogen codoped carbon nanoarchitectures to tailor molecularly imprinted polymers for PFOS determination
PublicationPer- and polyfluoroalkyl substances (PFAS) have gained significant attention as emerging contaminants due to their persistence, abundance, and adverse health effects. Consequently, the urgent need for ubiquitous and effective sensors capable of detecting and quantifying PFAS in complex environmental samples has become a priority. In this study, we present the development of an ultrasensitive molecularly imprinted polymer (MIP)...
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Mass Spectrometry-Based Direct Analytical Techniques
PublicationDirect analysis of samples is considered as one of the most environmentally sustainable solutions in analytical chemistry. In the ideal case, such solutions do not require sample preparation and analytes separation steps, therefore do not consumpt harmful substances (or consumpt only minimum amounts of them) and do not generate hazardous waste. Technical solutions for direct analysis also offer miniaturized and field-portable analyzers...
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Quantum and carbon dots conjugated molecularly imprinted polymers as advanced nanomaterials for selective recognition of analytes in environmental, food and biomedical applications
PublicationSamples with complex matrix analyzed during explanation of pathogenesis of various diseases and food or environmental monitoring request advanced analytical and instrumental devices. Among the materials used for described purposes, quantum (QDs) or carbon dots (CDs) layered by molecularly imprinted polymer (MIP) shells have gained widespread attention. Unique optical and physicochemical properties of QDs/CDs together with high...
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Structural, magnetic and spectral properties of tetrahedral cobalt(II) silanethiolates: a variety of structures and manifestation of field-induced slow magnetic relaxation
PublicationBlue crystals of five heteroleptic cobalt(II) silanethiolates 1–5 have been obtained by the reaction of [Co{SSi (tBuO)3}2(NH3)]2 with aminopyridines and aminomethylpyridines at an appropriate molar ratio and their structural, spectral, thermal and magnetic properties have been established and described. All complexes 1–5 contain Co(II) ions in a tetrahedral CoN2S2 environment formed by (tBuO)3SiS− residues and pyridines and present...
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Further Developments of the Online Sound Restoration System for Digital Library Applications
PublicationNew signal processing algorithms were introduced to the online service for audio restoration available at the web address: www.youarchive.net. Missing or distorted audio samples are estimated using a specific implementation of the Jannsen interpolation method. The algorithm is based on the autoregressive model (AR) combined with the iterative complementation of signal samples. Since the interpolation algorithm is computationally...
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Online sound restoration system for digital library applications.
PublicationAudio signal processing algorithms were introduced to the new online non-commercial service for audio restoration intended to enhance the content of digitized audio repositories. Missing or distorted audio samples are predicted using neural networks and a specific implementation of the Jannsen interpolation method based on the autoregressive model (AR) combined with the iterative restoring of missing signal samples. Since the distortion...
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Mercury in Living Organisms: Sources and Forms of Occurrence, Bioaccumulation, and Determination Methods
PublicationMercury (Hg) is a heavy metal with well-known and broadly tested toxicity. Since Hg pollution and its impacts on human health are of global concern, it has become necessary to develop analytical methodologies that will provide tools to obtain reliable analytical information about the levels of Hg in samples, which very often have a complex matrix composition. This chapter summarizes key information on Hg and its chemical forms,...
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Combined extraction and microextraction techniques: Recent trends and future perspectives
PublicationThe latest advancements in the analytical sample preparation indicate a trend of combining different extraction techniques with targeting an improvement in separation, cleanup, detection limits, enrichment factors, and dealing with complex matrices. This manuscript identifies mainly two groups of combined sample preparation techniques. The first group integrates conventional or enhanced extraction techniques with microextraction....
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A new dilution-enrichment sample preparation strategy for expanded metabolome monitoring of human breast milk that overcomes the simultaneous presence of low- and high-abundance lipid species
PublicationThe complex nature of human breast milk (HBM) makes samples difficult to analyze, requiring several extraction techniques and analytical platforms to obtain high metabolome coverage. In this work, we combined liquid-liquid extraction (LLE) and solid-phase extraction (SPE) techniques to prepare HBM samples to overcome the challenge of low- and high-abundance lipid species, enabling the semiquantitative analysis of total HBM lipids...
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Electronic and ionic relaxations in strontium-borate glass and glass-ceramics containing bismuth and vanadium oxides
PublicationThe topography, microstructure and electrical properties of strontium-borate glass and SBO glass containing bismuth and vanadium oxides, were studied. The structure was measured using X-ray diffraction (XRD), Energy Dispersive X-ray Spectrometer (EDS) and Scanning electron microscope (SEM) methods. The A.C. complex conductivity was investigated as a function of temperature and frequency. The influence of the quantity of bismuth...
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Golden artefacts, resin figurines, body adhesives and tomb sediments from the pre-Columbian burial site El Caño (Gran Coclé, Panamá): tracing organic contents using molecular archaeometry
PublicationThis research aimed to determine the origin of organic residues from funerary contexts in the El Ca~no settlement (Gran Cocl�e area, Panam�a, Central America) by means of multiple molecular probing techniques (GC-MS of organic solvent extracts and pyrolysis-GC-MS, THM-GC-MS and FTIR of solid samples). The samples include particles of precious resin figurines, fillings of golden objects, tomb sediments, plant exudates from extant...
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Quantitative assessment
PublicationThe main trends in the development of analytical chemistry are the determination of increasingly lower concentrations of analytes in samples with complex matrix composition (trace analysis). While the obtained analytical results must be reliable, which means that they must accurately (truly and precisely) reflect the actual content of analytes in a representative sample of the material object under study. However, it is an extremely...
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Immunoanalityka – użyteczne podejście analityczne w badaniach środowiska
PublicationWażnym krokiem w rozwoju bezpośrednich metodyk analitycznych było opracowanie technik immunoanalitycznych. Początkowo znalazły one zastosowanie praktyczne w analityce medycznej a później także w analityce środowiskowej. Dzięki temu możliwe jest ilościowe oznaczenie stosunkowo szerokiego spektrum ksenobiotyków w próbkach charakteryzujących się złożonym składem matrycy bez praco- i czasochłonnego etapu przygotowania tych próbek do...
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Analityka surfaktantów w próbkach środowiskowych
PublicationSurfaktanty stanowią grupę związków charakteryzujących się specyficznymi właściwościami fizykochemicznymi (m.in. amfifilowa budowa, zdolność rozpuszczania się w cieczach o różnej polarności, zdolność do tworzenia micelli) i z tego względu są one wykorzystywane w wielu sferach działalności człowieka. Związki powierzchniowo-czynne ulegają różnorodnym przemianom fizykochemicznym, co umożliwia ich migrację między różnymi elementami...
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Pre-analytical aspects in metabolomics of human biofluids – sample collection, handling, transport, and storage
PublicationMetabolomics is the field of omics research that offers valuable insights into the complex composition of biological samples. It has found wide application in clinical diagnostics, disease investigation, therapy prediction, monitoring of treatment efficiency, drug discovery, or in-depth analysis of sample composition. A suitable study design constitutes the fundamental requirements to ensure robust and reliable results from the...