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Wyniki wyszukiwania dla: organic acids
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Ion Chromatography in Environmental Analysis of Selected Organic Acids
PublikacjaLow molecular mass carboxylic acids (LCAs) occur in many environmental compartments dueto natural processes and human activity. When volatile and nonvolatile acids are to be monitored then liquidchromatography, including ion chromatography seems a method of choice. At high pH the acids are inionized form and can be separated as carboxylats by means of anion exchange chromatography. LCAs canalso be separated at low pH by ion exclusion...
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Determination and identification of organic acids in wine samples. Problems and challenges.
PublikacjaFor long time, organic acids were underestimated. However, during last two decades there is an increasing interest of natural compounds having antioxidant, antimicrobial and anti-inflammatory properties thus organic acids are very preferable. Wine stands as one of the sources of organic acids since they are responsible for its organoleptic and aestethic character. Nevertheless, it is important to not exceed acceptable level of...
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Capillary Electrophoresis in Determination of Low Molecular Mass Organic Acids
PublikacjaThis paper presents overviews the capabilities of capillary electrophoretic techniques to determine low molecular mass organic acids in a variety of aqueous, gas and solid samples. It mainly focuses on short - chain carboxylic acids containing one or more carboxylic groups and possibly some other functional groups (hydroxyl, keto-, amino- etc.). Finally the procedures applied to the determine the acids in different matrices are...
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Determination of Selected Organic Acids in Animal Farm Water Samples by Ion Chromatography
PublikacjaLow molecular mass carboxylic acids (LCAs) occur in many environmental compartments due to natural processes and human activity. They are an important group of organic pollutants of waste water that mainly includes, volatile fatty acids, and also dicarboxylic, aromatic, hydroxy- and ketoacids. LCAs are present in the environment at concentrations between 1 to 5000 ppm and different methods have been reported for their determination...
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Chemistry induced by low-energy electrons in condensed multilayers of pure small organic acids
PublikacjaPrzedstawiono reakcje indukowane przez niskoenergetyczne elektrony (0.7 - 20 eV) w kondensowanych warstwach kwasu mrówkowego (HCOOH), częściowo deuterowanego kwasu octowego (CH3COOD) oraz kwasu trifluorooctowego (CF3COOD).
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Identification of organic acids as potential biomarkers in the urine of autistic children using gas chromatography/mass spectrometry
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Multivariate Statistical Analysis for Mutual Dependence Assessment of Selected Polyphenols, Organic Acids and Metals in Cool-Climate Wines
PublikacjaPolyphenols, organic acids and metal ions are an important group of compounds that affect the human health and quality of food and beverage products, including wines. It is known that a specific correlation between these groups exist. While wines coming from the New World and the Old World countries are extensively studied, wines coming from cool-climate countries are rarely discussed in the literature. One of the goals of this...
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TiO2 Modified with Organic Acids for the Decomposition of Chlorfenvinphos under the Influence of Visible Light: Activity, Performance, Adsorption, and Kinetics
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Organic Acids and Polyphenols Determination in Polish Wines by Ultrasound-Assisted Solvent Extraction of Porous Membrane-Packed Liquid Samples
PublikacjaIn the near future, Poland is going to have more and more favorable conditions for viticulture. Organic acids and polyphenols are among the most commonly analyzed compounds due to their beneficial properties for human health and their importance in the winemaking process. In this work, a new technique involving ultrasound-assisted solvent extraction of porous membrane-packed liquid samples (UASE-PMLS) was for the first time described...
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The conversion of multinuclear μ-oxo titanium(IV) species in the reaction of Ti(OiBu)4 with branched organic acids; results of structural and spectroscopic studies
PublikacjaW reakcji tetraizobutoksylanu tytanu z rozgałęzionymi kwasami karboksylowymi otrzymano szereg wielordzeniowych związków kompleksowych tytanu(IV). Otrzymane produkty scharakteryzowano wykorzystując techniki spektroskopowe: FTIR, 1H i 13C NMR oraz rentgenowską analizę strukturalną. Zaproponowano ścieżki reakcji prowadzące do konwersji poszczególnych związków w coraz stabilniejsze formy.
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Comparison of the Antibacterial Activity of Selected Deep Eutectic Solvents (DESs) and Deep Eutectic Solvents Comprising Organic Acids (OA‐DESs) Toward Gram‐Positive and Gram‐Negative Species
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Hydrodynamic cavitation based advanced oxidation processes: Studies on specific effects of inorganic acids on the degradation effectiveness of organic pollutants
PublikacjaThe use of cavitation in advanced oxidation processes (AOPs) to treat acidic effluents and process water has become a promising trend in the area of environmental protection. The pH value of effluents – often acidified using an inorganic acid, is one of the key parameters of optimization process. However, in the majority of cases the effect of kind of inorganic acid on the effectiveness of degradation is not studied. The present...
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Development of headspace-gas chromatography-flame ionization detection procedure to determine volatile fatty acids in zoo organic waste leachate
PublikacjaNadrzędnym celem pracy było opracowanie metodyki oznaczania lotnych kwasów tłuszczowych z fazy nadpowierzchniowej opartej na chromatografii gazowej z detektorem płomieniowo-jonizacyjnym oraz sprawdzenie jej przydatności w analizie próbek odcieku ze składowiska odpadów ogrodu zoologicznego. Na podstawie przeprowadzonych badań określono warunki, w jakich przebiegać powinna izolacja lotnych kwasów tłuszczowych, a także określono najlepsze...
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Oznaczanie śladowych ilości związków organicznych w próbkach o złożonych matrycach zgodne z regułami ''zielonej chemii analitycznej''. Krótkołańcuchowe kwasy karboksylowe = Increasingly green approaches to the determination of selected trace organic in complex matrices. Short chain carboxylic acids
PublikacjaNowadays the great stress is put on environment protection and the activities to minimize the effect of chemical analyses on the environment are discussed. When environmentally friendly methodologies of analytes determination are applied the term "green analytical chemistry" is used. In general, the determination of organic compounds in complex matrices, which is a frequent analytical task, requires separation of sample components...
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Studies on applicability of new solid-phase microextraction fibers for the selective extraction and determination of short - chain monocarboksylic acids
PublikacjaShort-chain monocarobxylic acids, sometimes referred to as volatile fatty acids (VFA), are a group of low molecular weight alkyl monocarboxylic acids that are widely distributed within the environment. These molecules contain any from 2 to 8 carbon atoms and originate from the anaerobic biodegradation of organic matter such as carbohydrates, proteins, and fats. These compounds are commonly found in the effluents from animal farming,...
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Production, Transformation and Determination of Volatile Fatty Acids in Farm Animals and the Environment
PublikacjaThe paper is a critical discussion of the production, transportation and determination of volatile fatty acids in rumens of ruminants. The odor nuisance of the emission of VFAs, often accompanied by volatile nitrogen- and sulfur-organic compounds from animal farming is also discussed.
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Studies on applicability of new solid-phase microextraction and determination of short - chain monocarboxylic acids
PublikacjaA convenient approach to monitor the short-chain monocaroboksylic acids (SCAMs) in different samples is gas chromatography (GC) preceded by sample preparation based on solid-phase microextraction (SPME). The fiber with polar coatings were used to extract the SCAMs from headspace of liquid and solid samples. Recently polimeric ionic liquid (PIL) fiber coatings have been proposed to extract volatile organic compounds, minly polar...
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The influence of humic substances in treated sewage on the quality of surface waters
PublikacjaAt present the evaluation of WWTP effectiveness is based upon organic matter and nutrients removal. Recently it was found out that sewage treatment leads to formation of resistant to biochemical degradation organic compounds, similar to humic acids. The humic acids formed during sewage treatment process play diversified functions when discharged to surface waters - for instance they can act as carriers of hydrophobic organic pollutants...
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Treated wasetewater as a source of humic substances in surface waters
PublikacjaHumic substances impose substantial effect on the aquatic environment as well as the water organisms and human health. Among other features, the humic acids determine organoleptic properties of surface waters. Therefore explanation of the origin and properties of humic acids in surface waters is one of the priorities of water technology.Recently it was pointed out that in the wastewater treatment process organic compounds characterized...
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Acyl Meldrum's acid derivatives: application in organic synthesis
PublikacjaThis review is focused on one of the most important classes of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleiophiles. The possible mechanisms of these transformations...
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New empirical correlations for the viscosity of selected organic phase change materials
PublikacjaAlthough there are many methods and instruments for measuring viscosity, it is still difficult to determine a reliable value of the dynamic viscosity of complex chemicals such as paraffins and fatty acids. This is due to the complex and heterogeneous structure of these compounds in the case of commercial products. On the other hand, the measuring instrument should be selected very carefully, including its measuring principle and...
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Sample preparation procedure using extraction and derivatization of carboxylic acids from aqueous samples by means of deep eutectic solvents for gas chromatographic-mass spectrometric analysis
PublikacjaThe paper presents a new procedure for the determination of organic acids in a complex aqueous matrixusing ultrasound-assisted dispersive liquid–liquid microextraction followed by injection port derivati-zation and GC–MS analysis. A deep eutectic solvent (choline chloride: 4-methylphenol in a 1:2 mol ratio)was used both as an extracting solvent and as a derivatizing agent to yield ion pairs which were next con-verted to methyl...
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Chemistry and Nanochemistry 2024
Kursy OnlineWe start from General Chemistry, including: calculus in chemistry, bonds, balancing the chemical reactions, redox reactions, electrochemistry, pH, acids, bases, salts, oxides, organic molecules, and many informations about synthesis, analysis and applications in nanochemistry.
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Chemistry and Nanochemistry 2023
Kursy OnlineWe start from General Chemistry, including: calculus in chemistry, bonds, balancing the chemical reactions, redox reactions, electrochemistry, pH, acids, bases, salts, oxides, organic molecules, and many informations about synthesis, analysis and applications in nanochemistry.
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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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Non-volatile molecular composition and discrimination of single grape white of chardonnay, riesling, sauvignon blanc and silvaner using untargeted GC–MS analysis
PublikacjaThis study developed and applied a GC–MS method aiming at molecular fingerprinting of 120 commercial single grape white wines (Chardonnay, Riesling, Sauvignon Blanc and Silvaner) for possible authentication according to grape variety. The method allowed detection of 372 peaks and tentative identification of 146 metabolites including alcohols, organic acids, esters, amino acids and sugars. The grape variety effect explained 8.3%...
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Biorefinery Approach for H2 and Acids Production Based on Uncontrolled pH Fermentation of an Industrial Effluent
PublikacjaIn this work, the feasibility of uncontrolled pH acidogenic fermentation of industrial organic effluent from corn-bioethanol production was studied and modelled by using a Monod-based mathematical model. In order to do that, several tests were carried out at different initial pH values, ranging from 4 to 6. The experimental data showed a pH reduction during the fermentation process due to the generation of short-chain acids. When...
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Distillation cleanup preceded gc determination of short-chain monocarboxylic acids in aqueous and solid samples of wastewater origin = Oznaczanie krótkołańcuchowych kwasów monokarboksylowych w próbkach wodnych i stałych pochodzących z oczyszczalni ścieków z wykorzystaniem chromatografii gazowej poprzedzonej destylacją
PublikacjaShort-chain monocarboxylic acids (SCMAs) (C2-C5) formed in the process of aerobic biodegradation of larger organic molecules should often be monitored to optimize wastewater biological treatment and study the processes of converting organic waste matter into methane, etc. Gas chromatography (GC) seems a method of choice for such a task. Majority of samples require clean up before they can be injected into GC system. In this work...
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Chapter 4. Electricity generation from glucose microbial fuel cell
PublikacjaThe microbial fuel cell was constructed to generate electricity with simultaneous digestion of a glucose fuel by a bacterial biofilm. The decomposition of glucose resulted in releasing of electrons to an anode and to production of some by-products, e.g. metane or organic acids. It was found that maximum electric power density strongly depended on the proton transport through the proton exchange membrane seperating the anolyte and...
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Solvothermal synthesis and structural characterization of three polyoxotitanium-organic acid clusters
PublikacjaThree new titanium oxo-clusters Ti4O2(OiPr)10(OOCPhMe)2 (I), Ti6O4(OEt)8(OOCPhMe)8 (II) and Ti6O6(OEt)6(OOCCHPh2)6 (III) were obtained by easy one-step solvothermal reactions of titanium(IV) isopropoxide, alcohols and carboxylic acids. The three compounds were characterized by single-crystal and powder X-ray diffraction, TGA/DSC, optical and electron microscopy, and FTIR and NMR spectroscopy. X-ray powder diffraction and spectroscopy...
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Comparative Analysis of Metabolic Variations, Antioxidant Profiles and Antimicrobial Activity of Salvia hispanica (Chia) Seed, Sprout, Leaf, Flower, Root and Herb Extracts
PublikacjaThe purpose of this study was to evaluate the phytochemical profiles of the seeds, sprouts, leaves, flowers, roots and herb of Salvia hispanica and to demonstrate their significant contribution to antioxidant and antimicrobial activities. Applied methods were: HPLC-DAD coupled with post-column derivatization with ABTS reagent, untargeted metabolomics performed by LC-Q-Orbitrap HRMS, and two-fold micro-dilution broth method, which...
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Microscopic Imaging to Visualize the Distribution of Dietary Nucleic Acids in Food Products of Various Origins
PublikacjaDietary nucleic acids (dietNAs) are being increasingly recognized as important food components with nutritional value. However, the precise dietary recommendations for dietNAs are limited, because established methods for determining the quantity and nutritional role of dietNAs are still lacking. One of the tools to narrow this gap could be microscopic imaging, as a convenient approach to visualize the abundance and distribution...
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Bioactive Ingredients with Health-Promoting Properties of Strawberry Fruit (Fragaria x ananassa Duchesne)
PublikacjaStrawberries (Fragaria x ananassa Duchesne) belong to the berry group and are characterized primarily by delightful sensory properties. Due to their chemical composition, these fruits are a rich source of bioactive compounds that can modify the metabolic and physiological functions of the body. The aim of this work is to present the current state of research on bioactive ingredients found in these fruits in the context of their...
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A Review on Metal–Organic Framework as a Promising Catalyst for Biodiesel Production ENERGY & FUELS
PublikacjaThe rapid depletion of fossil-derived fuels along with rising environmental pollution have motivated academics and manufacturers to pursue more environmentally friendly and sustainable energy options in today’s globe. Biodiesel has developed as an ecologically favorable alternative. However, the mass manufacturing of biodiesel on an industrial scale confronts substantial cost and pricing challenges. To address this issue, high-efficiency...
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Exposure to cooking emitted volatile organic compounds with recirculating and extracting ventilation solutions
PublikacjaEnergy-efficient urban development leads to the compact design of apartments. Recirculating ventilation solutions are an attempt to minimize the space required for ventilation ducting, but more data on their performance are needed. Cooking is a major source of volatile organic compounds (VOCs) emissions. It is necessary to assess how well recirculating kitchen hoods perform in reducing the residents' exposure to cooking fumes compared...
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Detection of Bioactive Compounds in Organically and Conventionally Grown Asparagus Spears
PublikacjaIn the recent reports, there are contradictory conclusions about the nutritional and health properties of organic and conventionally growing vegetables. We hypothesized that organic cultivation system results in higher quality of asparagus (Asparagus officinalis L.) because of organic manure and effective organisms. Therefore, new analytical methods were applied in order to find the differences in bioactive compounds between the...
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Partial characterization of three Korean white lotus cultivars
PublikacjaThe nutritional and bioactive values of Korean white lotus cultivars (Muan, Chungyang, and Garam)extracted with methanol, water, and acetone solvents were evaluated by the contents of their bioactive compounds and antioxidant activity determined by ABTS, CUPRAC, FRAP, DPPH, and β-carotene-linoleic acid assays. HPLC, fluorometry, and FTIR spectroscopy were employed for evaluation of polyphenols and fatty acids. All lotus cultivar...
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Salinity enhances high optically active L-lactate production from co-fermentation of food waste and waste activated sludge: Unveiling the response of microbial community shift and functional profiling
PublikacjaLactic acid (LA), a versatile platform molecule, can be fermented from organic wastes, such as food waste and waste activated sludge. In this study, an efficient approach using salt, a component of food waste as an additive, was proposed to increase LA production. The LA productivity was increased at 10 g NaCl/L and optical pure L-lactate was obtained at 30 g NaCl/L. The enhancement of LA was in accordance with the increased solubilization...
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Solid Phase Micro-Extraction, a Versatile and Handy Tool in Environmental Trace Organic Analysis, Gets a New Class of Coatings, Polymeric Ionic Liquids
PublikacjaSolid phase microextraction (SPME) fundamentals, characteristics and application are described. The special stress is put on characteristics of sorbents used as SPME fiber coatings. Description of commercially available fibers and the present-day trends in development of new sorbents for SPME are given. Discussion is focused on possibility of application of ionic liquids (IL) and polymeric ionic liquids (PIL) as SPME fiber coatings....
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Synthesis of 5-Substituted 1H-Tetrazoles from Nitriles in the Presence of Heterogeneous Catalyst
PublikacjaTetrazoles are five-membered heterocyclic compounds containing in their rings four nitrogen atoms. They have wide applications as corrosion inhibitors, analytical reagents, high-energy materials and gas generating compositions. Tetrazoles also play important role in coordination chemistry as ligands and in medicinal chemistry as metabolically stable surrogates for carboxylic acids. In recent years, investigation of new method of...
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Hydrophobic and hydrophilic properties of pollutants as a factor influencing their redistribution during snowpack melt
PublikacjaGlaciers accumulate organic pollutants delivered by snow. However, our understanding of the exact dynamics of organic pollutants in the snowpack relies primarily on laboratory experiments and mathematical models. To fill the gap related to the detailed field data, we have conducted observations of melting snow profiles in two locations and three different stages of melting on one High Arctic glacier, as well as in superimposed...
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Voriconazole-Based Salts Are Active against Multidrug-Resistant Human Pathogenic Yeasts
PublikacjaVoriconazole (VOR) hydrochloride is unequivocally converted into VOR lactates and valinates upon reaction with silver salts of organic acids. This study found that the anticandidal in vitro activity of these compounds was comparable or slightly better than that of VOR. The Candida albicans clinical isolate overexpressing CaCDR1/CaCDR2 genes, highly resistant to VOR, was apparently more susceptible to VOR salts. On the other hand,...
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Assessment and design of greener deep eutectic solvents – A multicriteria decision analysis
PublikacjaDeep eutectic solvents (DES) are often considered as green solvents because of their properties, such as negligible vapor pressure, biodegradability, low toxicity or natural origin of their components. Due to the fact that DES are cheaper than ionic liquids, they have gained many applications in a short period of time. However, claims about their greenness sometimes seem to be exaggerated. Especially, bearing in mind lots of data...
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Aminy w środowisku - niebezpieczeństwo czy jego naturalny element?
PublikacjaA lot of amines and their compounds are used in the industry. First of all they are used for the preparation of medicines, plant protection agents, fertilizers and plastics. Amines are also released into the environment as a result of natural biological processes such as the release of certain species of flowers to lure insects, and also biochemical breakdown of amino acids in the protein during decomposition of organic matter. Unfortunately,...
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Sewage sludge pretreatment by low thermal disintegration for better efficacy of sludge digestion process
PublikacjaThe wastewater water treatment plant (WWTP) sector and it is developing technologies strive to be implement circular economy. The methane production from the sludge digestion process constitute promising source of the renewable energy for WWTP and approaching circular economy assumptions. For this reason, the objective of the study was to examine the modification of sludge characteristics due to the low temperature pretreatment....
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Study of pH and temperature effect on lipophilicity of catechol-containing antioxidants by reversed phase liquid chromatography
PublikacjaLipophilicity of selected antioxidant phytochemicals, including flavonoids, phenolic acids and xanthonoids, was determined by reversed phase high performance liquid chromatography with UV detection (RP-HPLC-UV). The analyses run at different temperature and pH conditions in isocratic mode suggested that lipophilicity as distribution coefficient (logD) between aqueous and organic phase decreases with increasing temperature. For...
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Metals and metal-binding ligands in wine: Analytical challenges in identification.
PublikacjaBackground Due to important role of metals in the vinification process as well as their impact on the human health, their content in this alcoholic beverage has been extensively studied by many researchers. It is already known that speciation of metals determines their toxicity and bioavailability as well as influences their activity. Understanding the chemistry and knowing the structures of metal complexes could have relevant...
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Identification and characterization of the Indian Yellow dyestuff and its degradation products in historical oil paint tube by liquid chromatography mass spectrometry
PublikacjaAn analytical protocol for identification of dyes using reversed phase liquid chromatography-mass spectrometry with atmospheric pressure electrospray ionization (LC-ESI/MS) is presented. The developed method has been successfully applied in identification of euxanthic acid and euxanthone, the main components of the Indian Yellow dye in a historical oil paint tube produced by Richard Ain`es, a recognizable French company supplying...
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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
PublikacjaThis 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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Estimating the Impact of Inflow on the Chemistry of Two Different Caldera Type Lakes Located on the Bali Island (Indonesia)
PublikacjaThis paper is a preliminary attempt to assess the composition of pollutants in two different caldera lakes situated in the Indonesian Archipelago: Batur and Bratan. Both lakes are characterized by largely different physico-chemical regimes; Batur Lake is located in an area that is currently volcanically active, unlike Bratan Lake. The latter is much smaller and shallower than Batur Lake. The concentration of pollutants in the Indonesian...