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Wyniki wyszukiwania dla: METHANOL COMPLEX
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Permeation and sorption properties of poly(ether-block-amide) membranesfilled by two types of zeolites
PublikacjaThe experimental study of transport properties of mixed matrix membranes (MMMs) based on PEBA-4033 with two types of zeolites is reported. Gas (CO2, O2, N2) and vapor (benzene, toluene, methanol, water) permeation measurements were performed using the differential flow permeameter at temperature of 298.15 K and at atmospheric pressure. Gas/vapor permeation was monitored by measuring the changes of the thermal conductivity of carrier...
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Impedance monitoring of fuel cell stacks
PublikacjaThis paper presents an innovative, electrochemical impedance method for monitoring of electrochemical behaviour of a multi-cell, direct methanol fuel cell (DMFC) device. This method not only provides classical voltage changes at successive cells but also allows their detailed impedance behaviour to be presented. Impedance characteristics of individual cells within a fuel cell stack (depending on actual operating conditions) are...
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Mathematical modeling of hydrogen production performance in thermocatalytic reactor based on the intermetallic phase of Ni3Al
PublikacjaThe main goal of the following work is to adjust mathematical modelling for mass transfer, to specific conditions resulting from presence of chemical surface reactions in the flow of the mixture consisting of helium and methanol. The thermocatalytic devices used for decomposition of organic compounds incorporate microchannels coupled at the ends and heated to 500 oC at the walls regions. The results of the experiment were compared...
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Hydrogen Production Mechanism in Low-Temperature Methanol Decomposition Catalyzed by Ni3Sn4 Intermetallic Compound: A Combined Operando and Density Functional Theory Investigation
PublikacjaHydrogen production from methanol decomposition to syngas (H2 + CO) is a promising alternative route for clean energy transition. One major challenge is related to the quest for stable, cost-effective, and selective catalysts operating below 400 °C. We illustrate an investigation of the surface reactivity of a Ni3Sn4 catalyst working at 250 °C, by combining density functional theory, operando X-ray absorption spectroscopy, and high-resolution...
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Improvement of CO2 absorption and inhibition of NH3 escape during CaCO3 precipitation in the presence of selected alcohols and polyols
PublikacjaThis research aims to investigate the effect of selected organic substances containing hydroxyl groups on the reduction of NH3 escape and the improvement of CO2 capture during the precipitation of calcium carbonate by carbonation method using post-distillation liquid from the Solvay process and gas stream containing CO2 in the amount corresponding to the exhausted gases produced by the combustion of fossil fuels. Glycerol, ethylene...
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Chemical composition, antioxidant and anticancer effects of the seeds and leaves and indigo (polygonum tinctorium Ait.) Plant
PublikacjaSeeds and leaves of indigo (Polygonum tinctorium Ait.) plant were investigated and compared with another medicinal plant named prolipid for their properties such as chemical composition, antioxidant, and anticancer effects by Fourier transform infrared, three-dimensional fluorescence spectroscopy, and electrospray ionization-MS in negative mode. It was found that polyphenols, flavonoids, and flavanols were significantly higher...
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Electrocatalytic oxidation of methanol, ethylene glycol and glycerine in alkaline media on TiO2 nanotubes decorated with AuCu nanoparticles for an application in fuel cells
PublikacjaIn this work, we present the catalytic and photocatalytic activity of AuCu nanostructures obtained on TiO2 nanotubes toward methanol, ethylene glycol and glycerine oxidation. The electrode material is prepared by anodization of Ti foil, thin AuCu layer sputtering and rapid thermal treatment under argon atmosphere. Scanning electron microscopy images confirmed the presence of ordered tubular architecture of TiO2 as well as nanoparticles...
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Dimethyl ether (DME) as potential environmental friendly fuel
PublikacjaIn recent years, there has been a growing interest in replacing petroleum fuels with so-called second generation environmental friendly fuels. Compared to traditional petroleum fuels dimethyl ether (DME) could be used as a clean high-efficiency compression ignition fuel with reduced particulate matter (PM), sulfur oxides (SOx), hydrocarbons (HC), carbon monoxide (CO) as well as combustion noise. Compared to some of the other leading...
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Chromatographic lipophilicity determination using large volume injections of the solvents non-miscible with the mobile phase
PublikacjaA new perspective in the lipophilicity evaluation through RP-HPLC is permitted by analysis of the retentionfactor (k) obtained by injecting large volumes of test samples prepared in solvents immiscible withmobile phase. The experiment is carried out on representative groups of compounds with increasedtoxicity (mycotoxins and alkaloids) and amines with important biological activity (naturally occurringmonoamine compounds and related...
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Determination of parent and methylated polycyclic aromatic hydrocarbons in water samples by dispersive liquid–liquid microextraction–two dimensional gas chromatography–time-of-flight mass spectrometry
PublikacjaPolycyclic aromatic hydrocarbons (PAHs) are contaminants frequently found in environmental waters. Owing to their toxic effects, it is important to develop analytical methodologies that allow their fast and reliable determination. Dispersive liquid–liquid microextraction (DLLME) allows a quick extraction of analytes with little organic solvent consumption. The best results regarding sample preparation are obtained when 40 mL of...
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Coordination polymers and molecular structures among complexes of mercury(II) halides with selected 1-benzoylthioureas
PublikacjaSix new 1-benzoyl-3-phenylthiourea and 1-benzoyl-3-(2-methylphenyl)thiourea complexes of mercury( II) were obtained in the reactions of the ligands with HgX2 in methanol (X = Cl, Br, I). Their structures, determined by single-crystal X-ray diffraction analysis, exhibit different stoichiometries and molecular organization. Coordination centers adopt more or less distorted tetrahedral geometry (five structures) or distorted trigonal...
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Color prediction from first principle quantum chemistry computations: a case of alizarin dissolved in methanol
PublikacjaThe electronic spectrum of alizarin (AZ) in methanol solution was measured and used as reference data for color prediction. The visible part of the spectrum was modelled by different DFT functionals within the TD-DFT framework. The results of a broad range of functionals applied for theoretical spectrum prediction were compared against experimental data by a direct color comparison. The tristimulus model of color expressed in terms...
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Towards Computer-Aided Graphene Covered TiO2-Cu/(CuxOy) Composite Design for the Purpose of Photoinduced Hydrogen Evolution
PublikacjaIn search a hydrogen source, we synthesized TiO2-Cu-graphene composite photocatalyst for hydrogen evolution. The catalyst is a new and unique material as it consists of copper-decorated TiO2 particles covered tightly in graphene and obtained in a fluidized bed reactor. Both, reduction of copper from Cu(CH3COO) at the surface of TiO2 particles and covering of TiO2-Cu in graphene thin layer by Chemical Vapour Deposition (CVD) were...
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Assessment of Lipophilicity Indices Derived from Retention Behavior of Antioxidant Compounds in RP-HPLC
PublikacjaReverse phase high pressure liquid chromatography was employed in order to evaluate the lipophilicity of antioxidant compounds from different classes, such as phenolic acids, flavanones, flavanols, flavones, anthocyanins, stilbenes, xantonoids, and proanthocyanidins. The retention time of each compound was measured using five different HPLC columns: RP18 (LiChroCART, Purosphere RP-18e), C8 (Zorbax, Eclipse XDBC8), C16-Amide (Discovery...
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Recent Progress on Hydrogen Storage and Production Using Chemical Hydrogen Carriers
PublikacjaDepleting fossil fuel resources and anthropogenic climate changes are the reasons for the intensive development of new, sustainable technologies based on renewable energy sources. One of the most promising strategies is the utilization of hydrogen as an energy vector. However, the limiting issue for large-scale commercialization of hydrogen technologies is a safe, efficient, and economical method of gas storage. In industrial practice,...
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Polycyclic aromatic hydrocarbons as test probes to investigate the retention behavior of 1,3-alternate calix[4]arene silica-bonded stationary phases
PublikacjaA series of polycyclic aromatic hydrocarbons (PAHs) of different size and shape has been used to characterize the chromatographic behavior of five calix[4]arene stationary phases in 1,3-alternate conformation synthesized in our laboratory. The selection of linear, fourring nonlinear, and five-ring PAHs gave data on selectivity changes across range of the calix[4]arene columns. Retention of the 12 aromatic solutes has been evaluated...
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The Analysis of Vodka: A Review Paper
PublikacjaVodka is the most popular alcoholic beverage in Poland, Russia and other Eastern European countries, made from ethyl alcohol of agricultural origin that has been produced via fermentation of potatoes, grains or other agricultural products. Despite distillation and multiple filtering, it is not possible to produce 100 % ethanol. The solution with a minimum ethanol content of 96 %, which is used to produce vodkas, also contains trace amounts...
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Mono- and bi-metallic plasmonic photocatalysts for degradation of organic compounds under UV and visible light irradiation
PublikacjaTitania powders were surface modified with gold and/or silver nanoparticles (NPs) by photodeposition method. Gold modified titania exhibited much higher photocatalytic activity during methanol dehydrogenation under UV irradiation than titania modified with monometallic silver and bimetallic Au–Ag NPs. Bimetallic photocatalysts exhibited either enhanced or reduced visible light activity, depending on properties of noble metal NPs,...
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Thermodynamic Characteristics of Phenacetin in Solid State and Saturated Solutions in Several Neat and Binary Solvents
PublikacjaThe thermodynamic properties of phenacetin in solid state and in saturated conditions in neat and binary solvents were characterized based on differential scanning calorimetry and spectroscopic solubility measurements. The temperature-related heat capacity values measured for both the solid and melt states were provided and used for precise determination of the values for ideal solubility, fusion thermodynamic functions, and...
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Performance of the PEM fuel cell module. Part 2. Effect of excess ratio and stack temperature
PublikacjaThe paper describes a fuel cell based system performance under different thermal conditions. The system could be fed with bottled hydrogen or with very high purity hydrogen obtained from reforming of methanol. The system is based on two fuel cell units (1.2 kW each, produced by Ballard Power Systems Inc. and called Nexa), DC/DC converter, DC/AC inverter, microprocessor control unit, load unit, bottled hydrogen supply system and...
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Seeding enhancement for microcrystaline diamond layers growth on non-diamond substrates
PublikacjaThe present paper gives an overview on the possible methods of seeding substrates for diamond layers growth. Diamond in reason of his properties is very desirable material in microelectronic, biomedical and waste treatment sensors. Microcrystalline diamond for these applications must be grown on silicon substrate in microwave plasma assisted chemical vapor deposition (MPACVD). To grow diamond on non-diamond surface pre-growth...
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Sensitive determination of isoprostanes in exhaled breath condensate samples with use of liquid chromatography-tandem mass spectrometry
PublikacjaOxidative stress is the hallmark of various inflammatory lung diseases. Increased concentrations of reactive oxygen species in the lungs are reflected by elevated concentrations of oxidative stress markers in the breath, airways, lung tissue and blood. The aim of this work was to develop a method for the fast measurement of F2 isoprostanes in exhaled breath condensate (EBC) samples using equipment which is nowadays available and...
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An in situ derivatization – dispersive liquid–liquid microextraction combined with gas-chromatography – mass spectrometry for determining biogenic amines in home-made fermented alcoholic drinks
PublikacjaA novel dispersive liquid–liquid microextraction (DLLME) gas chromatography mass-spectrometry(GC–MS) method was developed for the determination of 13 biogenic amines in home-made wine sam-ples. The method allows to simultaneous extraction and derivatization of the amines providing a simpleand fast mode of extract enrichment. During the study, two different procedures were examined. Sta-tistical analysis was performed to choose...
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Photocatalytic and Antimicrobial Properties of Ag2O/TiO2 Heterojunction
PublikacjaAg2O/TiO2 heterojunctions were prepared by a simple method, i.e., the grinding of argentous oxide with six different titania photocatalysts. The physicochemical properties of the obtained photocatalysts were characterized by diffuse-reflectance spectroscopy (DRS), X-ray powder diffraction (XRD) and scanning transmission electron microscopy (STEM) with an energy dispersive X-ray spectroscopy (EDS). The photocatalytic activity was...
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Towards azeotropic MeOH-MTBE separation using pervaporation chitosan-based deep eutectic solvent membranes
PublikacjaDeep eutectic solvents (DESs) are a new class of solvents that can offset some of the major drawbacks of common solvents and ionic liquids. When dealing with the preparation of dense membranes, the use of DESs is still challenging due to their low compatibility with the polymer phase. In this research, a novel L-proline:sulfolane (molar ratio 1:2) DES was synthesized and used for the preparation of more sustainable bio-based membranes...
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The role of biodegradable particulate and colloidal organic compounds in biological nutrient removal activated sludge systems
PublikacjaThe efficiency of denitrification and enhanced biological phosphorus removal in biological nutrient removal activated sludge systems is strongly dependent on the availability of appropriate carbon sources. Due to high costs of commercial compounds (such as methanol, ethanol, acetic acid, etc.) and acclimation periods (usually) required, the effective use of internal substrates is preferred. The aim of this study was to determine...
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Application of a commercially available derivatization instrument and commonly used reagents to HPLC on-line determination of antioxidants
PublikacjaThis study demonstrates the potential of a commercially available derivatization instrument coupled with HPLC for separation and on-line determination of antioxidants detected with widely used screening reagents - DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) or FCR (Folin-Ciocalteu's phenol reagent ). As the result of optimization, key parameters of the analytical procedure,...
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Enzyme Conjugation - A Promising Tool for Bio-catalytic and Biotransformation Applications – A Review
PublikacjaEnzymes have revolutionized conventional industrial catalysts as more efficient, eco-friendly, and sustainable substitutes that can be used in different biotechnological processes, food, and pharmaceutical industries. Yet, the enzymes from nature are engineered to make them adapt and enhance their durability in the industrial environment. One promising approach involves the combined use of multiple enzymes that catalyze highly...
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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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RAPESEED PELLET - A BYPRODUCT OF BIODIESEL PRODUCTION - AS AN EXCELLENT RENEWABLE ENERGY SOURCE
PublikacjaVegetable oils are renewable feedstock currently being used for production of biofuels from sustainable biomass resources. The existing technology for producing diesel fuel from plant oils, such as rapeseed, soybean, canola and palm oil are largely centered on transesterification of oils with methanol to produce fatty acid methyl esters (FAME) or biodiesel. Rapeseed pellet - crushed seed residue from oil extraction is a byproduct...
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Lepidium peruvianum as a Source of Compounds with Anticancer and Cosmetic Applications
PublikacjaLepidium peruvianum—an edible herbaceous biennial plant distributed in the Andes—has been used for centuries as food and as a natural medicine in treating hormonal disorders, as an antidepressant, and as an anti-osteoporotic agent. The presented study aims to prove its beneficial cosmetic and chemopreventive properties by testing the antiradical, whitening, cytotoxic, and anticancer properties of differently colored phenotypes...
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Fast, sensitive and reliable multi-residue method for routine determination of 34 pesticides from various chemical groups in water samples by using dispersive liquid – liquid microextraction coupled with gas chromatography – mass spectrometry
PublikacjaA simple and efficient dispersive liquid-liquid microextraction technique (DLLME) was developed by using a mixture of two solvents: 40 μL of tetrachlorethylene (extraction solvent) and 1.0 mL of methanol (disperser solvent), which was rapidly injected with a syringe into 10mL ofwater sample. Some important parameters affecting the extraction efficiency, such as type and volume of solvents, water sample volume, extraction time,...
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Stabilities of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and their derivatives under controlled conditions analyzed using liquid chromatography coupled with tandem mass spectrometry
PublikacjaBisphenol A diglycidyl ether (BADGE), bisphenol F diglycydyl ether (BFDGE), and their related compounds are widely used as precursors in production of epoxy resins. The high reactivity of these compounds makes the development of analytical methodologies that ensure appropriate metrological accuracy crucial. Consequently, we aimed to determine whether and to what extent the composition of the solution and storage conditions affect...
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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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Shape-controllable synthesis of GdVO4 photocatalysts and their tunable properties in photocatalytic hydrogen generation
PublikacjaNovel visible light responsive materials for water splitting are essential for the efficient conversion of solar energy into hydrogen bond energy. Among other semiconductors, gadolinium orthovanadate has appropriate conduction and valence band edges positioned to split water molecules and a narrow band gap that allows the use of visible light for hydrogen generation. Thus, we present here that hydrogen evolution under visible light...
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Application of COSMO-RS-DARE as a Tool for Testing Consistency of Solubility Data: Case of Coumarin in Neat Alcohols
PublikacjaCoumarin is a naturally occurring lactone-type benzopyrone with various applications in the pharmaceutical, food, perfume, and cosmetics industries. This hydrophobic compound is poorly soluble in water but dissolves well in protic organic solvents such as alcohols. Despite the extensive use of coumarin, there are only a few reports documenting its solubility in organic solvents, and some reported data are incongruent, which...
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On the mechanism of photocatalytic reactions on CuxO@TiO2 core–shell photocatalysts
PublikacjaTitania (titanium(IV) oxide) is a highly active, stable, cheap and abundant photocatalyst, and is thus commonly applied in various environmental applications. However, two main shortcomings of titania, i.e., charge carrier recombination and inactivity under visible-light (vis) irradiation, should be overcome for widespread commercialization. Accordingly, titania has been doped, surface modified and coupled with various ions/compounds,...
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Influence of steam cooking on pro-health properties of Small and Large variety of Momordica charantia
PublikacjaSteam cooking is one of the most common preparations of Momordicacharantia dishes. This method improved the tastiness of the fruits but at the same time, some changes occurred in the volatile and non-volatile parts of their food matrices. In this study, for the first time these properties were correlated with the found substances affecting the bioactivity of this fruit. Two varieties of Momordicacharantia were analysed and compared....
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Mono- and bimetallic (Pt/Cu) titanium(IV) oxide core–shell photocatalysts with UV/Vis light activity and magnetic separability
PublikacjaTitanium(IV) oxide is one of the most widely investigated photocatalysts. However, separation of nano-sized particulate titania might result in profitless technologies for commercial applications. Additionally, bare titania is almost inactive under the Vis range of solar spectrum due to its wide bandgap. Therefore, the present study aims to prepare novel coreinterlayer- shell TiO2 magnetic photocatalysts modified with metal nanoparticles...
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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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The preparation and evaluation of core-shell magnetic dummy-template molecularly imprinted polymers for preliminary recognition of the low-mass polybrominated diphenyl ethers from aqueous solutions
PublikacjaThe design, preparation process, binding abilities, morphological characteristic and prospective field of application of dummy-template magnetic molecularly imprinted polymer (DMMIP) for preliminary recognition of the selected low-mass polybrominated diphenyl ethers (PBDE-47 and PBDE-99) from aquatic environment were investigated. The surface of iron oxide (Fe3O4) nanopowder (50-100 nm particles size) was modified with tetraethoxysilane...
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Deep eutectic solvent-based shaking-assisted extraction for determination of bioactive compounds from Norway spruce roots
PublikacjaPolyphenolic compounds play an essential role in plant growth, reproduction, and defense mechanisms against pathogens and environmental stresses. Extracting these compounds is the initial step in assessing phytochemical changes, where the choice of extraction method significantly influences the extracted analytes. However, due to environmental factors, analyzing numerous samples is necessary for statistically significant results,...
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DETERMINATION OF SURFACTANTS IN ENVIRONMENTAL SAMPLES. PART II. ANIONIC COMPOUNDS
PublikacjaSurfactants (SAA) with negative charge of polar group are named as anionic compounds. They are main constituent of most products containing synthetic surfactants. The linear alkylbenzene sulfonates (LAS), alkyl ethoxysulfates (AES) and alkyl sulfates (AS) are typically applied from this class of compounds. Those surfactants are ingredients of household detergents and cleaners, laundry detergents, cosmetic. Moreover they can be...