Wyszukiwarka
Wyniki wyszukiwania dla: IMPURITIES
-
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...
-
Types of Surface Impurities versus the Quality of Brazed Joints
PublikacjaBrazing is one of the primary joining processes increasingly often applied in industry. Because of their mechanical properties, overlap joints are particularly popular when making brazed structures. The use of brazed joints in structures of critical importance requires that particular attention be paid to joint quality, e.g. by the appropriate cleaning of surfaces to be joined. The article presents results of non-destructive tests...
-
Impact and practicability of recently introduced requirements on elemental impurities
Publikacja -
Determination of the chemical structure of potencial organic impurities occuring in the drug substance opopramol
PublikacjaThe tricyclic antipsychotic and antidepressant drug opipramol was examined with regard to the chemical structure of its organic impurities. Impurities were isolated from the technical product by chromatographic methods and their chemical structures were estabilished by HMNR, MS and FTIR.
-
Determination of the chemical structure of potential organic impurities occurring in drug substance opipramol
PublikacjaThe tricyclic antipsychotic and antidepressant drug opipramol (opipramole) was examined with regard to the chemical structure of its organic impurities. Impurities were isolated from the technical product by chromatographic methods and their chemical structures were established by 1H NMR, MS and FTIR and further confirmed by comparison with commercially available products or with products obtained by independent synthesis, and...
-
Entanglement in S states of two-electron quantum dots with Coulomb impurities at the center
Publikacja -
Influence of the rare-earth impurities on the Ga and Ge local structure in the Ca3Ga2Ge3O12 glass
PublikacjaW pracy przedstawione zostały wyniki analizy EXAFS realizowanejza pomocą metody GNXAS dla serii szkieł typu Ca3Ga2Ge3O12 domieszkowanych metalami ziem rzadkich (0.7 wt.% - Ce, Eu, Ho, Er; oraz 1.0 wt.% Nd). Badaniu poddano lokalne otoczenie wokół jonów Ge i Ga. Porównanie wyników z danymi strukturalnymi otrzymanymi dla szkła niedomieszkowanego wskazuje, że domieszka metali ziem rzadkich modyfikuje jedynie otoczenie jonów galu,...
-
Forced Degradation Studies of Ivabradine and In Silico Toxicology Predictions for Its New Designated Impurities
PublikacjaAll activities should aim to eliminate genotoxic impurities and/or protect the API against degradation. There is a necessity to monitor impurities from all classification groups, hence ivabradine forced degradation studies were performed. Ivabradine was proved to be quite durable active substance, but still new and with insufficient stability data. Increased temperature, acid, base, oxidation reagents and light were found to cause...
-
Forced degradation studies of ivabradine and in silico toxicology predictions for its new designated impurities
PublikacjaAll activities should aim to eliminate genotoxic impurities and/or protect the API againstdegradation. There is a necessity to monitor impurities from all classification groups,hence ivabradine forced degradation studies were performed. Ivabradine was provedto be quite durable active substance, but still new and with insufficient stability data.Increased temperature, acid, base, oxidation reagents and...
-
MicroscopicA75sNMR study of the effect of impurities on the first-order spin-density-wave transition inBaFe2As2
Publikacja -
Study of impurities in alpha-Al 2 O 3 powders and crystals using EPR spectroscopy
Publikacja -
Microscopic 75^As NMR study of the effect of impurities on the first-order spin-density-wave transition in BaFe2As2
PublikacjaOpisane są wyniki badań NMR na 75^As w monokryształach i próbkach polikrystalicznych BaFe2As2. Zanieczyszczenia cyną wpływają na niskoenergetyczne fluktuacje spinowe i obniżają temperaturę krytyczną ze 138K do 85K.
-
Elimination of metal catalyst and carbon-like impurities from single-wall carbon nanotube raw material
Publikacja -
Inhibition of impurities formation in the synthesis of N-alkyltheobromines stimulated by microwave irradiation. Cationic and anionic response of membrane electrodes
PublikacjaN-Alkyltheobromine (1-9) derivatives were obtained by reacting theobromine with appropriate alkyl halide under microwave irradiation at 100-150 W and by conventional synthesis. Formation of by-products of oxygen atom alkylation and 1-N-alkyltheobromine ring opening were considered. The presented compounds 1-5 have been studied as ion carriers in ion-selective membrane electrodes. Selectivity of these membranes was studied towards...
-
Synthesis of highly crystalline photocatalysts based on TiO2 and ZnO for the degradation of organic impurities under visible-light irradiation
PublikacjaA TiO2–ZnO binary oxide system (with molar ratio TiO2:ZnO = 8:2) was synthesized by a hydrothermal method, assisted by calcination at temperatures of 500, 600 and 700 °C, using zinc citrate as the precursor of ZnO. The morphology (SEM, TEM), crystalline structure (XRD, Raman spectroscopy), diffuse reflectance spectra (DRS), chemical surface composition (EDXRF), porous structure parameters (low-temperature N2 sorption) and characteristic...
-
Ewa Klugmann-Radziemska prof. dr hab.
OsobyEwa Klugmann-Radziemska ukończyła studia wyższe na kierunku fizyka na Uniwersytecie Gdańskim, a od roku 1996 związana jest z Politechniką Gdańską, kiedy to rozpoczęła studia doktoranckie. Obecnie jest profesorem na Wydziale Chemicznym Politechniki Gdańskiej, od roku 2006 kierownikiem Katedry Aparatury i Maszynoznawstwa Chemicznego. W latach 2008–2016 pełniła funkcję Prodziekana ds. współpracy i rozwoju, w latach 2016-2019 była...
-
Comparative X-ray diffraction and Mössbauer spectroscopy studies of BiFeO3 ceramics prepared by conventional solid-state reaction and mechanical activation
PublikacjaThe aim of this work was to prepare BiFeO3 by modified solid-state sintering and mechanical activation processes and to investigate the structure and hyperfine interactions of the material. X-ray diffraction and Mössbauer spectroscopy were applied as complementary methods. In the case of sintering, BiFeO3 phase was obtained from the mixture of precursors with 3 and 5 % excess of Bi2O3 during heating at 1023 K. Small amounts of...
-
LC-MS and LC-NMR as Complementary Techniques for the Determination of Pharmaceuticals in Dosage Formulations
PublikacjaPharmaceuticals contain not only pharmacologically active compounds but also a range of excipients. The danger exists that impurities may also be present in such drugs, which may adversely affect their efficacy and even endanger patient health and life. Monitoring the composition of pharmaceutical products is therefore essential. The trace amounts of such impurities in pharmaceuticals are often identified and determined with liquid...
-
Structural investigations of the LTO:Cu thin films
Dane BadawczeLithium titanate (Li1+xTi2-xO4) doped with Cu2+ ions was synthesized by sol-gel processing method. The structure was characterized by X-ray Diffraction (XRD). All samples revealed presence of LTO spinel phase. X-ray pattern of undoped LTO was free of any impurities and other crystal phases. Similarly, samples with low amount of copper dopant (x = 0.05...
-
Decrease in Photovoltaic Module Efficiency Due to Deposition of Pollutants
PublikacjaThe deposition of pollutants on the surface of photovoltaic (PV) modules reduce the efficiency that can be achieved in given climatic conditions. This results in the loss of energy yield obtained from the solar installation. A number of factors determine the scale of this problem. The first of these is the amount of impurities deposited, the associated amount of precipitation, and the speed and direction of the wind. A second aspect...
-
Methane formation over TiO2–based photocatalysts: reaction pathways
PublikacjaThe effects of organic impurities adsorbed or incorporated into semiconductors structure on the photocatalytic products are noteworthy. For this purpose, the as-prepared Ag, Au and Pdmodified TiO2 samples were exposed to UV-vis irradiation in various gas atmospheres (CO2, N2, 600 ppm CO2 in N2, and 13CO2) in order to clarify the route of CH4 formation in the process of photocatalytic CO2 reduction. In the presented research it...
-
Mathematical Modeling of the Impact Range of Sewage Discharge on the Vistula Water Quality in the Region of Włocławek
PublikacjaThe paper presents results of analysis of the industrial sewage discharge influence at km 688 + 250 of the Vistula River on water quality. During the analysis, two-dimensional models of flow, impurities and temperature transport were used. Hydrological conditions of the analyzed section of the river, characteristic flows and bathymetry of the riverbed in the first instance were defined. Calculations of velocity distribution at...
-
Urządzenie do wytwarzania gazowych mieszanin wzorcowych z wykorzystaniem procesu barbotażu oraz permeacji
PublikacjaReference gas mixtures are classified to reference materials and are mainly used for quality monitoring and identification of impurities in atmospheric air. They can be also used for calibration of measuring devices. Nowadays, there is a need to develop a new techniques for the preparation of reference gas mixtures [1, 2]. In this paper the design and the operating principles of instrument based on the use of barbotage and permeation...
-
Study on surface termination of boron-doped diamond electrodes under anodic polarization in H2SO4 by means of dynamic impedance technique
PublikacjaAnodic oxidation is a popular way to modify termination bonds at boron doped diamond electrodes altering their electrochemical and physicochemical properties. Our studies, performed with dynamic electrochemical impedance spectroscopy technique, supported with X-ray photoelectron spectroscopy and ellipsometry analysis prove its utility in continuous on-line monitoring of impedance changes on the electrode surface under polarization...
-
Process Control of Biogas Purification Using Electronic Nose
PublikacjaNowadays, biogas produced from landfills and wastewater treatment plants or lignocellulosic biomass is important sustainable and affordable source of energy. Impurities from biogas stream can cause a serious odor problem, especially for residents of areas immediately adjacent to production plants. Therefore, biogas pre-treatment is necessary to protect engines that convert biogas into energy and in order to increase the specific...
-
ANALYSIS OF THE IMPACT OF THE PLANNED SEWAGE DISCHARGE FROM THE ‘NORTH’ POWER PLANT ON THE VISTULA WATER QUALITY
PublikacjaThe paper presents results of analysis of the industrial sewage discharge impact from the ‘North’ Power Plant on the Vistula water quality around 45+330 of the river kilometer. For the analysis, the two-dimensional models of flow, impurities and temperature transport were used. Hydrological conditions of the analyzed section of the river, characteristic flows and bathymetry of the riverbed in the first instance were defined....
-
Chemical-Assisted Mechanical Lapping of Thin Boron-Doped Diamond Films: A Fast Route Toward High Electrochemical Performance for Sensing Devices
PublikacjaThere is an urgent need for an effective and economically viable increase in electrochemical performance of boron-doped diamond (BDD) electrodes that are used in sensing and electrocatalytic applications. Specifically, one must take into consideration the electrode heterogeneity due to nonhomogenous boron-dopant distribution and the removal of sp2 carbon impurities saturating the electrode, without interference in material integrity....
-
PROCESSING, MECHANICAL AND THERMAL PROPERTIES OF RECYCLED LOW-DENSITY POLYETHYLENE STREAMS
PublikacjaThe recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for the potential methods of their utilization. Nevertheless, for the efficient application of recycled materials it is crucial to analyze their performance. Therefore, in presented paper we investigated the processing (melt flow index),...
-
Chitosan-based nanomaterials for removal of water pollutants
PublikacjaThe rise of micropollutants presents a significant threat to both the environment and human well-being, requiring effective strategies for their mitigation. Chitin serves as the precursor for chitosan, composed of two monomers featuring acetamido and amino groups. Chitosan possesses several noteworthy attributes, including its ability to bind water and fat, humidity content, solubility, consistent molecular weight, and various...
-
Synthesis of disubstituted 1,3,4,9-tetrahydropyrano-[3,4-b]indole-1-acetic acids derivatives
Publikacja1,3,4,9-tetrahydropyrano[3,4-b ]indole-1-acetic acid derivatives are of interest for pharmaceutical research as a core structure for synthesis of biological active substance - Etodolac (selective Cyclooxygenase-2 inhibitor, which belongs to the Non-steroidal Anti-inflammatory Drug, NSAID, that shows a clin-ically effective analgesic and anti-inflammatory activity). Here the way of synthesis of two 1,3,4,9-tetrahydropyrano[3,4-b...
-
COMPARISON OF TWO MODELS OF CONDENSATION
PublikacjaIn the low-pressure part of steam turbine, the state path usually crosses the saturation line in penultimate stages. At least last two stages of this part of turbines operate in two –phase region. The liquid phase in this region in mainly created in the process of homogeneous and heterogeneous condensation. Several observations confirm however, that condensation often occurs earlier than it is predicted by theory i.e. before the...
-
Wastes from Agricultural Silage Film Recycling Line as a Potential Polymer Materials
PublikacjaThe recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for potential methods for their utilization. In the presented work, we investigated the recycling potential of wastes originated from the agricultural films recycling line. Their structure and properties were analyzed, and they were...
-
Recent breakthroughs in the stability testing of pharmaceutical compounds
PublikacjaPharmaceutical development is mostly focused on the research leading to approval of a new and viable active substance. However, there is a number of old generation compounds that are still being used in contemporary medicinal practice. So that new analytical developments should cover not only the safety of newly developed drug substances, which is obvious, but should also be directed into the search of individual stability issues...
-
Detection of apple in orange juice using ultra-fast gas chromatography
PublikacjaThe determination of authenticity is an increasingly important issue for food quality and safety. The use of an electronic nose based on ultra-fast gas chromatography technique ensures rapid analysis of the volatile compounds from food products. Due to the fact that this technique enables chemical profiling of agricultural products, it can be an effective tool for authentication when combined with chemometrics. In this article...
-
The LaPdIn 4 indide and elementary properties of the LaTIn 4 ( T = Ni, Pd, Pt) materials family
PublikacjaThe indium-rich intermetallic compound LaPdIn4 is reported, prepared by arc-melting and annealing at 600 C. Single crystal X-ray diffraction found the material to be orthorhombic, space group Cmcm (No. 63), with lattice parameters a ¼ 4.5462(3) Å, b ¼ 16.9208(10) Å, and c ¼ 7.3100(5) Å. This previously unreported indide is isostructural with LaNiIn4 and LaPtIn4. It is demonstrated that all three compounds in the LaTIn4 (T ¼ Ni,...
-
Theoretical and Economic Evaluation of Low-Cost Deep Eutectic Solvents for Effective Biogas Upgrading to Bio-Methane
PublikacjaThis paper presents the theoretical screening of 23 low-cost deep eutectic solvents (DESs) as absorbents for effective removal of the main impurities from biogas streams using a conductor-like screening model for real solvents (COSMO-RS). Based on thermodynamic parameters, i.e., the activity coefficient, excess enthalpy, and Henry’s constant, two DESs composed of choline chloride: urea in a 1:2 molar ratio (ChCl:U 1:2), and choline...
-
THE STUDY OF WATER POLLUTION OF THE LOWER VISTULA RIVER BY PLASTIC PARTICLES
PublikacjaSince the beginning of widespread use of plastic its consumption and production has been constantly increasing. As a result of human activity part of waste ends up in our environment and is deposited in each of the elements of the biosphere. These impurities can be in the form of large elements, small particles fragmented to macroscopic level (pellets, facial scrub grains) and the microparticles visible under a microscope. Particularly...
-
Novel analytical method for detection of orange juice adulteration based on ultra-fast gas chromatography
PublikacjaThe food authenticity assessment is an increasingly important issue in food quality and safety. The application of an electronic nose based on ultra-fast gas chromatography technique enables rapid analysis of the volatile compounds from food samples. Due to the fact that this technique provides chemical profiling of natural products, it can be a powerful tool for authentication in combination with chemometrics. In this article,...
-
Quality Control of Bacterial Extracellular Vesicles with Total Protein Content Assay, Nanoparticles Tracking Analysis, and Capillary Electrophoresis
PublikacjaExtracellular vesicles (EVs) were isolated from Pectobacterium zantedeschiae culturing media using direct ultracentrifugation (UC), iodixanol cushion ultracentrifugation (ICUC), and iodixanol density gradient ultracentrifugation (IDGUC) techniques. The isolates were characterized with total protein content assay (bicinchoninic acid assay, BCA), nanoparticles tracking analysis (NTA), and capillary electrophoresis (CE). A satisfactory...
-
RESEARCH ON ORGANIC COATINGS DESIGNED FOR UNDERWATER APPLICATIONS
PublikacjaUnderwater steel structures require periodic maintenance. In the case of vessels, anti-corrosion works are carried out in the shipyard, where very good conditions for applying organic protective coatings can be provided. Very good surface preparation can be obtained by the use of abrasive blasting. The well-prepared metal surface is free from impurities (particularly inorganic salts). Suitable conditions for the application and...
-
Assessment of unusual failure in crankshaft of heavy-duty truck engine
PublikacjaThe unusual premature failure of a heavy-duty truck engine crankshaft has been the subject of a rigorous study, and this manuscript describes it in detail. The failure was happened to begin with the growth of the crack from the surface defects, in the form of the clusters of non-metallic inclusions, in the lubrication hole zone of the first main journal, which was the stress concentration zone. A series of experiments including...
-
The fast identification of explosives, natcotics and other chemicals carried on board of ships or transported in containers
PublikacjaThe fast identification of explosives, narcotics and other chemicals carried on board of ships or transported in containers to the harbors is an important problem of maritime security. Raman spectroscopy is an advanced technique used in state-of-the art laboratories for fast identification of chemicals. No sample preparation is required, and identification can be carried out through transparent packing, such as plastic or glass,...
-
Consequences of New Approach of Chemical Stability Tests of Active Pharmaceutical Ingredients (APIs)
PublikacjaThere is a great need of broaden look on stability tests of active pharmaceuticalingredients (APIs) in comparison with current requirements contained in pharmacopeia.By usage of many modern analytical methods the conception of monitoring the changesof APIs during initial stage of their exposure to harmful factors has been developed. Newknowledge must be acquired in terms of identification of each degradation...
-
Progressing Pollutant Elution from Snowpack and Evolution of its Physicochemical Properties During Melting Period— a Case Study From the Sudetes, Poland
PublikacjaMain aim of the work assumed recognition of physicochemical changes in snowpack occurring during the melting period. Properties of snow cover had been identified at two sites in Western Sudetes mountains (860 and 1228 m asl) in SW Poland since the end of January, and monitored until the disappearance of snow in late Spring. Snow pit measurements and sample collection at both sites were made followed by chemical analyses with the...
-
Development of a new green analytical methodology for the determination of phthalates in single-use babies diapers using ultrasound-assisted extraction and polypropylene porous membrane
PublikacjaA green extraction strategy was developed and utilized for the extraction and determination of phthalates. The extraction is based on ultrasound-assisted extraction and a polypropylene porous membrane. The Box-Behnken model was performed to optimize the extraction condition. The optimal extraction conditions are 5.5 mL of ethyl acetate, 10 min of extraction time and 55 C for extraction temperature. The developed green extraction...
-
Ranking of Heterogeneous Catalysts Metals by Their Greenness
PublikacjaCatalysis is very important process in industry and laboratory practice, especially from the point of green chemistry principles. However, eco-friendly character of heterogeneous catalysts, containing transition metal components has not been evaluated, yet. Therefore, we perform a comprehensive assessment of 18 heterogeneous metal catalysts (Pd, Pt, V, Co, Ni, Mo, Ru, Mn, Au, Cu, Cd, Zr, Fe, Rh, Ir, Sn, Zn, Ag) using multicriteria...
-
Shading, Dusting and Incorrect Positioning of Photovoltaic Modules as Important Factors in Performance Reduction
PublikacjaThe amount of solar radiation reaching the front cover of a photovoltaic module is crucial for its performance. A number of factors must be taken into account at the design stage of the solar installation, which will ensure maximum utilization of the potential arising from the location. During the operation of a photovoltaic installation, it is necessary to limit the shading of the modules caused by both dust and shadowing by trees...
-
Seaweed utilization issues in biogas production
PublikacjaMacroalgae can be seen as a renewable feedstock for the production of biofuels in many coastal areas around the World and especially in Baltic Sea region where the eutrophication is particularly troublesome. The investigation of anaerobic digestion technologies for extracting inexhaustible bioenergy from seaweed was conducted in many research institutions mainly in laboratory scale. Although seaweeds seem to have a great potential...
-
Integrated Experimental and Theoretical Approach for Efficient Design and Synthesis of Gold-Based Double Halide Perovskites
PublikacjaApplied cutting-edge electronic structure and phonon simulations provide a reliable knowledge about the stability of perovskite structures and their electronic properties, which are crucial for design of effective nanomaterials. Gold is one of the exceptional elements, which can exist both as a monovalent and a trivalent ion in the B site of a double perovskite such as A2BI BIIIX6. However, until now, electronic properties of Cs2AuI AuIIIX6...
-
Signature of Oxide-Ion Conduction in Alkaline-Earth-Metal-Doped Y3GaO6
PublikacjaWe have studied alkaline-earth-metal-doped Y3GaO6 as a new family of oxide-ion conductor. Solid solutions of Y3GaO6 and 2% −Ca2+-, −Sr2+-, and −Ba2+-doped Y3GaO6, i.e., Y(3−0.06)M0.06GaO6−δ (M = Ca2+, Sr2+, and Ba2+), were prepared via a conventional solid-state reaction route. X-ray Rietveld refined diffractograms of all the compositions showed the formation of an orthorhombic structure having the Cmc21 space group. Scanning electron...