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Wyniki wyszukiwania dla: DEEP EUTECTIC SOLVENTS, EXTRACTION, GREEN SOLVENTS, MICROEXTRACTION
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Evaluation of polycaprolactone as a new sorbent coating for determination of polar organic compounds in water samples using membrane–SPME
PublikacjaCommercially available solid-phase microextraction fibers used for isolation of polar analytes are based on the adsorption phenomenon. In consequence, typical limitations bonded with analytes displacement and matrix effects are very frequent. In the present study, alternative solution is described. Polycaprolactone (PCL) was used for the first time as sorbent to isolate polar organic compounds from water samples using the membrane–solid-phase...
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The reactions of dialkyl phosphites and phosphine oxides with iodosylbenzene
PublikacjaThe reaction of iodosylbenzene with >P(O)H type of acids (dialkyl phosphites, secondary phosphine oxides) was studied. The acids of >P(O)H type add to iodosylbenzene to yield intermediate 6 which in the aprotic solvents yields oxidation products, it means >P(O)OH acids and/or anhydride of >P(O)OP(O)< type. On the other hand if the reaction is performed in alcohol as a solvent in the presence of sodium alcoholate >P(O)OR ester is...
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Lab-in-syringe as a practical technique for automatic microextraction: Evaluation by Blue Applicability Grade Index
PublikacjaLab-in-syringe (LIS) is a powerful automatic technique that is derived from sequential injection analysis. In LIS, a computer-controlled syringe pump is employed, and its syringe barrel serves as a mixing, reaction, and/or extraction chamber. Until now, the LIS concept has been efficiently employed for the automation of solid-phase microextraction and liquid-phase microextraction protocols as a front-end to a plethora of chromatographic...
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Monolithic capsule phase microextraction prior to gas chromatography-mass spectrometry for the determination of organochlorine pesticides in environmental water samples
PublikacjaIn this study, a capsule phase microextraction (CPME) protocol followed by gas chromatography-mass spectrometry is proposed for the accurate and sensitive monitoring of organochlorine pesticides (OCPs) in environmental water samples. Different monolithic sol–gel encapsulated sorbents were compared and monolithic sol–gel poly(ethylene glycol)-based sorbent incorporated into porous microextraction capsules resulted in the highest...
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Spectroscopic studies of a ring opening process between epoxy- and aminosilanes and imine formation reactions in aqueous solutions
PublikacjaNMR and Raman spectroscopy studies were performed for different 3-aminopropyl(trimethoxy)- and 3-glycidoxypropyl (trimethoxy)silane based sol-gel systems containing different ketones. Exceptionally stable imine products were obtained depending on a reaction system at alkaline pH conditions and in the presence of water. These imine formation reactions were carried out without further catalyst. In addition, effect of water for the...
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Understanding the origin of high corrosion inhibition efficiency of bee products towards aluminium alloys in alkaline environments
PublikacjaVarious bee products were found to be efficient corrosion inhibitors of aluminium in different environments. In particular, bee pollen was found to be highly effective in alkaline electrolytes, yet its highly complex composition and possible synergistic interactions hinder determination of the compounds acting as active corrosion inhibitors. The main purpose of the following work is to investigate the effect of solvents used for...
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The influence of α,ω-diols and SiO2 particles on CO2 absorption and NH3 escaping during carbon dioxide capture in ammonia solutions
PublikacjaAmmonia solutions are widely used solvents for CO2 capture. However, a significant disadvantage of these solvents is secondary pollution of the purified gas stream by desorbed ammonia. In this work, α,ω-diols, and colloidal silica have been proposed to reduce this undesired effect. Ammonia solutions with the addition of ethylene glycol (EG), 1,3-propanediol (PRD), 1,4-butanediol (BUD), 1,5-pentanediol (PED), or 1,6-hexanediol (HED)...
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On the Structure and Volumetric Properties of Solvated Lanthanoid(III) Ions in Amide Solutions
PublikacjaThe coordination chemistry and the volumetric properties of three representative lanthanoid(III) ions lanthanum-(III), gadolinium(III), and lutetium(III) have been studied in three amide solvents with gradually increasing spatial demand upon coordination: N,N-dimethylformamide (dmf)
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Bio-Based Polyurethane Networks Derived from Liquefied Sawdust
PublikacjaThe utilization of forestry waste resources in the production of polyurethane resins is a promising green alternative to the use of unsustainable resources. Liquefaction of wood-based biomass gives polyols with properties depending on the reagents used. In this article, the liquefaction of forestry wastes, including sawdust, in solvents such as glycerol and polyethylene glycol was investigated. The liquefaction process was carried...
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Principles and Developments of Solid-Phase Microextraction
PublikacjaSample preparation has been commonly considered a critical step of the analytical process. In this sense, remarkable efforts have been made to develop efficient sample preparation techniques which could overcome the limitations of conventional approaches. Since its inception in the early 1990’s, solid-phase microextraction (SPME) has become a widespread miniaturized sample preparation technique for extraction and preconcentration...
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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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Chemometrics and Statistics | Multicriteria Decision Making
PublikacjaThis contribution describes the application of Multicriteria Decision Making tools in analytical chemistry. The general scheme of MCDM is presented to show its general steps. The most frequently applied in analytical sciences MCDM techniques – AHP, ELECTRE, PROMETHEE and TOPSIS – are briefly described and their advantages and disadvantages are discussed. The applications in analytical chemistry are selection of an appropriate...
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Thermodynamics and Intermolecular Interactions of Nicotinamide in Neat and Binary Solutions: Experimental Measurements and COSMO-RS Concentration Dependent Reactions Investigations
PublikacjaIn this study, the temperature-dependent solubility of nicotinamide (niacin) was measured in six neat solvents and five aqueous-organic binary mixtures (methanol, 1,4-dioxane, acetonitrile, DMSO and DMF). It was discovered that the selected set of organic solvents offer all sorts of solvent effects, including co-solvent, synergistic, and anti-solvent features, enabling flexible tuning of niacin solubility. In addition, differential...
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Controlling the size and morphology of precipitated calcite particles by the selection of solvent composition
PublikacjaCalcium carbonate particles were obtained in the reaction of calcium hydroxide with carbon dioxide at 65°C. Initial Ca(OH)2 suspensions were prepared in pure water and aqueous solutions of ethylene glycol or glycerol of the concentration range up to 20% (vol.). The course of reaction was monitored by conductivity measurements. Precipitated solids were analyzed by FTIR, XRD, SEM and the particles size distribution was determined...
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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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Predicting sulfanilamide solubility in the binary mixtures using a reference solvent approach
PublikacjaBackground. Solubility is a fundamental physicochemical property of active pharmaceutical ingredients. The optimization of a dissolution medium aims not only to increase solubility and other aspects are to be included such as environmental impact, toxicity degree, availability, and costs. Obtaining comprehensive...
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Synthesis and properties of new 'N,'N-phenyltetrazole podand
PublikacjaThe synthesis of a new chromogenic N,N-phenyltetrazole receptor is reported here. The cationbinding properties of this receptor in solution were investigated by naked-eye colour change, electrochemical methods and UV-Vis spectroscopy in various solvents (CH3CN, dimethylsulphoxide (DMSO), DMSO/H2O, CH3CN/H2O and CH3CN/MeOH). In addition, the receptor was used as a sensing material in ion-selective membrane electrodes. The selectivity...
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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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Miniaturized solid-phase extraction techniques
PublikacjaMore than 80% of analysis time is spent on sample collection and sample preparation, so sample preparation is a critical part of the analytical process. Traditionally, liquid-liquid extraction was developed and employed to screen for general unknowns. However, solid-phase extraction (SPE) is becoming highly popular as an alternative, due to its simplicity and economy in terms of time and solvent. This review summarizes the current...
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Rheology of liquid crystalline polymers
PublikacjaLiquid crystallinity was invented in the 19th century. It was sometimes called the fourth state of matter because of the ability of macromolecules to generate liquid crystal phases. The main classification divided liquid crystalline polymers (LCPs) into lyotropic and thermotropic types. Interpretation of the rheological behavior of LCP is more complicated than for other polymers. Ordinary polymers are characterized by a normal...
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Application of Headspace Solid-phase Microextraction with Poly(1-vinyl-3- Hexylimidazolium Chloride) Polymeric Ionic Liquid Coating using GC - MS to Determine Volatile Fatty Acids in Dairy Wastewater
PublikacjaVolatile fatty acids were determined in this study using headspace solid-phase microextraction (HS-SPME) with a poly(1-vinyl-3-hexylimidazolium chloride) polymeric ionic liquid coated fiber followed by gas chromatography - mass spectrometry. Experimental parameters such as extraction time and temperature, sample volume as well as desorption time and temperature were optimized. Detection limits of the method were in the range of...
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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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Solid phase microextraction–comprehensive twodimensional gas chromatography–time-of-flight mass spectrometry: a new tool for determining PAHs in airport runoff water samples
Publikacjafundamental aspect of airport operations is the pollution caused by airport runoff waters. Polycyclic aromatic hydrocarbons (PAHs) are one of the most important groups of xenobiotics which are commonly found in runoff water originating from airports. Only very limited data on the analysis of airport runoff water have been published until now. Therefore, a reliable and accurate analytical method based on headspace solid-phase microextraction...
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Volatile Organohalogen Compounds Determination with Dispersive Liquid-Liquid Microextraction Applying Solvent Lighter than Water
PublikacjaBackground: Volatile organohalogen compounds (VOX) are a group of environmental pollutants that risk the quality of drinking water. These compounds are characterized by certain acute and chronic toxicities, possessing mutagenic properties. Because of these potential risks factors that these compounds cause, the maximum allowable concentrations (MACs) have been established by respective organizations. The abundance of VOX, their...
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The dispersive micro-solid phase extraction method for MS-based lipidomics of human breast milk*
PublikacjaA simple and rapid microextraction method ensuring high lipidome coverage was developed for liquid chromatography mass spectrometry (LC-MS)-based lipidomics of human breast milk. The dispersive microsolid phase extraction (D-µ-SPE) technique, coupled with the design of experiment (DoE) method, enabled the study of the influence of several conditions (desorption solvent, stationary phase ratio, and sorption and desorption time)...
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Niebezpieczeństwo ukryte w żywności-aminy biogenne. Cz. II. Metody oznaczania i wyzwania.
PublikacjaZe względu na aktywność biologiczną amin biogennych ich oznaczanie zarówno jakościowe, jak i ilościowe w żywności ma istotne znaczenie w celu zapewnienia ochrony zdrowia i życia ludzkiego. Obecnie do monitoringu amin biogennych w żywności najczęściej wykorzystuje się: wysokosprawną chromatografię cieczową (HPLC), chromatografię cienkowarstwową (TLC) oraz absorpcyjną spektrofotometrię cząsteczkową. Są to jednak techniki czasochłonne,...
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A Green Chemistry "environmentally friendly" approach to the synthesis of chloro-intermediates of ephedrine/pseudoephedrine
PublikacjaMethylamphetamine is an addictive stimulant drug that strongly activates certain systems in the brain. It is closely related chemically to amphetamine, but the central nervous system effects of methamphetamine are greater. There is much interest in methylamphetamine among scientists and therefore the synthesizes of methylamphetamine and its metabolites are carried out on a large scale in chemical laboratories. Globally, ephedrine...
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Troubleshooting of the determination of bisphenol A at ultra-trace levels by liquid chromatography and tandem mass spectrometry
PublikacjaDetermination of trace amounts of bisphenol A (BPA) may cause problems mainly related to the presence of BPA in solvents (even in LC-MS grade), laboratory vessels, and plastic equipment used for sample preparation. Variable and sometimes significant amounts of BPA present in the background cause problems in obtaining good repeatability of measurements at the ultra-trace levels. Such observations (i.e., poor repeatability of results)...
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Sample Preparation in Foodomics: Miniaturized Solid-Phase Extraction
PublikacjaAnalytical chemists face a challenge to bring comprehensive information on a given food and biological sample by using the best available analytical techniques and meet the requirements of sustainable development and green chemistry at the same time. A key objective of this chapter is to review selected literature data on the utilization of solid-phase extraction techniques with special attention to their miniaturized modes in...
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Interplay of hydrogen bonding and aryl-perfluoroaryl interactions in construction of supramolecular aggregates
PublikacjaThe stacking between aryl and perfluoroaryl units is an important class of the aromatic – aromatic interactions that has attracted rapidly growing interest in recent years. Continuing interest of our group in this subject it had been prepared three new complexes of pentafluorobenzoic acid with benzyl alcohol, 4-methylbenzyl alcohol and 4-tert-butylbenzyl alcohol and in the next step investigated their self-assembly modes by...
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Determination of impurities in pharmaceutical products using LC-MS
PublikacjaPharmaceutical products can be contaminated by residues of solvents, reagents (used for the synthesis) or degradation products. Impurities in drug may pose a risk to human health and life, therefore analysis and identification of impurities in pharmaceutical products is veryimportant and inevitable.High performance liquid chromatography coupled with mass spectrometry (MS) is very useful technique for identification impurities in...
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Visualizing spatially decomposed intermolecular correlations in the infrared spectra of aprotic liquids
PublikacjaInfrared (IR) spectroscopy is commonly used to study intermolecular interactions in the liquid phase, including solvation phenomena. On the other hand, ab initio molecular dynamics (AIMD) simulations offer the possibility to obtain IR spectra from first principles. Surpassing the experiment, AIMD simulations can deliver additional information on the spatial intermolecular correlations underlying the IR spectrum of the liquid. Although...
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Main complications connected with detection, identification and determination of trace organic constituents in complex matrix samples
PublikacjaIt 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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Multivariate Assessment of Procedures for Molecularly Imprinted Polymer Synthesis for Pesticides Determination in Environmental and Agricultural Samples
PublikacjaIn the case of quantitative and qualitative analysis of pesticides in environmental and food samples, it is required to perform a sample pre-treatment process. It allows to minimalize the impact of interferences on the final results, as well as increase the recovery rate. Nowadays, apart from routinely employed sample preparation techniques such as solid-phase extraction (SPE) or solid-phase microextraction (SPME), the application...
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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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Chemometrics approaches to green analytical chemistry procedure development
PublikacjaChemometric tools are widely used in analytical chemistry for the reduction of data dimensionality, grouping of variables and processing of analytical signals. They have also the potential to be applied in analytical procedure development with the aim of minimizing the procedure’s environmental impact. The design of experiment gives the possibility to obtain much better information on the system response than in case of “changing...
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Natural/bio-based sorbents as greener extractive materials for endocrine disrupting compounds in samples of different matrix composition
PublikacjaEndocrine-disrupting compounds (EDCs) are a group of chemicals that interfere with the endocrine system, leading to adverse effects on human health and the environment. Increasing concerns over the EDCs presence in various environmental compartments has driven the search for greener extraction materials. Recently, the use of polymers of natural origin (biopolymers) has been demonstrated to be an effective and promising research...
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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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Determination of volatile organic compounds in water samples using membrane-solid phase microextraction (M-SPME) (headspace version)
PublikacjaThe results of a study on the use of membrane-solid phase microextraction (M-SPME) for sampling volatile organic compounds (VOCs) from the headspace above the liquid medium are presented. The sampled VOCs were subsequently quantified by gas chromatography (GC). Two systems were compared in this study, i.e. a novel two-phase sorption system (M-SPME), and a commercial fibre. Headspace sampling using SPME was optimized with respect...
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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
PublikacjaFuel 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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Excess molar volume and viscosity deviation for binary mixtures of gamma-butyrolactone with dimethyl sulfoxide
PublikacjaThe densities of binary liquid mixtures of dimethyl sulfoxide and gamma-butyrolactone at (293.15, 298.15, 303.15 and 313.15) K and viscosity at T=298.15 K have been measured at atmospheric pressure over theentire range of concentration. From these data the excess molar volumes VE at (293.15, 298.15, 303.15 and 313.15) K and the viscosity deviation, the excess entropy, and the excess Gibbs energy of activation for viscous flow at...
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Programmed metalloporphyrins for self-assembly within light-harvesting stacks: 5,15-dicyano-10,20-bis(3,5-di-tert-butylphenyl)-porphyrinato zinc(II) and its push-pull 15-N,N-dialkylamino-5-cyano congeners obtained by a facile direct amination.
PublikacjaThe title dicyano compound was synthesized via cyanation and it self-assembles in nonpolar solvents giving red-shifted and broad absorption maxima just as the bacteriochlorophylls which are encountered in the light-harvesting organelles of early photosynthetic bacteria. In the crystal, stacks are formed through a hierarchic combination of π-stacking and a CNZn electrostatic interaction. Push−pull 15-N,N-dialkylamino-5-cyano congeners...
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Computational modeling of molecularly imprinted polymers as a green approach to the development of novel analytical sorbents
PublikacjaThe development of novel molecularly imprinted polymers (MIP) sorbents for specific chemical compounds require a lot of tedious and time-consuming laboratory work. Significant quantities of solvents and reagents are consumed in the course of the verification of appropriate configurations of polymerization reagents. Implementation of molecular modeling in the MIP sorbent development process appears to provide a solution to this...
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AGREEprep – Analytical greenness metric for sample preparation
PublikacjaThis work proposes for the first time, a metric tool that gives prominence to sample preparation. The developed metric (termed AGREEprep) was based on 10 categories of impact that were recalculated to 0 e1 scale sub-scores, and then used to calculate the final assessment score. The criteria of assessment evaluated, among others, the choice and use of solvents, materials and reagents, waste generation, energy consumption, sample...
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Determination of Terpene Profile in Cape gooseberry (Physalis peruviana L.) with Use of HS-SPME/GCxGC-TOFMS Method
PublikacjaFresh fruits and products made of them, especially fruit juice, provide the basic energetic substances (simple and complex sugars) and are a source of health beneficial vitamins, macro and microelements, antioxidants and compounds which are classified together with essential oils (for example terpenes), which positively affect human s health. The terpenes profile of cape gooseberry was determined by headspace solid--phase microextraction...
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Miniaturized Solid Phase Extraction techniques for different kind of pollutants analysis: State of the art and future perspectives – PART 1
PublikacjaSolid Phase Extraction (SPE) has been practiced in a modern form for more than half a century. It was constantly developing, driven by the analysts needs. These needs are coming from the importance to select an appropriate analytical method, which should have satisfactory accuracy, precision and sensitivity. In the case of sorbent-based microextraction techniques, the choice of miniaturized variants that meet these requirements...
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Ferrofluids based analytical extractions and evaluation of their greenness
PublikacjaFerrofluids are stable dispersions of magnetic nanoparticles in a carrier liquid. They have attracted considerable attention in analytical extractions as they combine fluid-like properties with magnetic character, providing magnetic control over the extraction process. The synthesis of ferrofluids is very straightforward, and it generally involves the preparation of magnetic nanoparticles, their coating, and then mixing in a suitable...
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Hybrid cross-linked chitosan/protonated-proline:glucose DES membranes with superior pervaporation performance for ethanol dehydration
PublikacjaThis work explores a protonated L-proline:glucose (molar ratio 5:1) deep eutectic solvent (DES) in fabricating biopolymer membranes utilizing chitosan (CS). Initially, the miscibility of CS and DES to prepare homogeneous dense blend membranes has been investigated. Different techniques, such as scanning electron microscopy, contact angle (CA), atomic force microscopy (AFM), Fourier transformed infrared spectroscopy (FTIR) and swelling...
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When Neural Networks Meet Decisional DNA: A Promising New Perspective for Knowledge Representation and Sharing
PublikacjaABSTRACT In this article, we introduce a novel concept combining neural network technology and Decisional DNA for knowledge representation and sharing. Instead of using traditional machine learning and knowledge discovery methods, this approach explores the way of knowledge extraction through deep learning processes based on a domain’s past decisional events captured by Decisional DNA. We compare our approach with kNN (k-nearest...