Filtry
wszystkich: 1252
wybranych: 1138
-
Katalog
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: SPECT
-
Comparison of peptide cancer signatures identified by mass spectrometry in serum of patients with head and neck, lung and colorectal cancers: Association with tumor progression
Publikacja -
Solid phase extraction with flame atomic absorption spectrometry for determination of traces of Ca, K, Mg and Na in quality control of white sugar
Publikacja -
Sensitive Determination of Cd in Small-Volume Samples by Miniaturized Liquid Drop Anode Atmospheric Pressure Glow Discharge Optical Emission Spectrometry
Publikacja -
Determination of mercury in mosses by novel cold vapor generation atmospheric pressure glow microdischarge optical emission spectrometry after multivariate optimization
Publikacja -
Development of direct-current, atmospheric-pressure, glow discharges generated in contact with flowing electrolyte solutions for elemental analysis by optical emission spectrometry
Publikacja -
Hanging drop cathode-atmospheric pressure glow discharge as a new method of sample introduction for inductively coupled plasma-optical emission spectrometry
Publikacja -
Boron-doped carbon nanowalls for fast and direct detection of cytochrome C and ricin by matrix-free laser desorption/ionization mass spectrometry
PublikacjaDetecting proteins via surface assisted laser desorption/ionization mass spectrometry (SALDI-MS) method is still highly challenging, and only few examples of nanomaterials have been demonstrated to perform such detection so far. In this study, carbon nanowalls (CNWs), vertically aligned graphene sheet-based materials, presenting specific morphology, dimensions, and boron doping levels have shown improved performances for both qualitative...
-
Analysis of volatile fraction of sweetie (Citrus maxima × Citrus paradisi) and its parent fruit using proton transfer reaction mass spectrometry
PublikacjaThe quality of the fruit is affected by several main ingredients and the aroma plays a fundamental role during the selection of fruit by consumers. In the case where several fruit have similar aromas and only one of them has specific health properties, it is very important to find the differences in the volatile organic compounds (VOCs) composition to distinguish these samples. Such situations are often found for hybrid fruit....
-
A new method for real-time monitoring of volatiles in frying fumes using proton transfer reaction mass spectrometry with time-of-flight analyse
PublikacjaTo safeguard the consumers’ well-being, it is necessary to develop novel methods for determination of carcinogens in food, including volatiles generated during frying. The currently used procedures for analysis of volatile fraction of vegetable oils are not based on real-time measurements and thus do not enable the determination of carcinogenic compounds in frying fumes; instead, only the headspace or liquid fraction is sampled....
-
Comprehensive determination of flavouring additives and nicotine in e-cigarette refill solutions. Part I: Liquid chromatography-tandem mass spectrometry analysis
PublikacjaLiquid chromatography-tandem mass spectrometry with electrospray ionization (HPLC-ESI–MS/MS) methods were developed for the simultaneous determination of 42 flavouring compounds and nicotine in liquids for e-cigarettes. The chromatographic separation was performed using an Ace® Ultracore™ SuperC18™ (100 × 2.1 mm, 2.5 μm) column in both acidic and alkaline pH conditions to separate all the compounds. A simple “dilute & shoot” approach...
-
Carbon nanowalls: A new versatile graphene based interface for laser desorption/ionization-mass spectrometry detection of small compounds in real samples.
PublikacjaCarbon nanowalls, vertically aligned graphene nanosheets, attract attention owing to their tunable band-gap, high conductivity, high mechanical robustness, high optical absorbance and other remarkable properties. In this paper, we report for the first time, the use of hydrophobic boron-doped carbon nanowalls (CNWs) for laser desorption/ionization of small compounds and their subsequent detection by mass spectrometry (LDI-MS). The...
-
Investigation of the Dynamism of Nanosized SOA Particle Formation in Indoor Air by a Scanning Mobility Particle Sizer and Proton-Transfer-Reaction Mass Spectrometry
PublikacjaTerpenes are VOCs of particular importance, since they are emitted from a wide range of indoor sources and are considered to be precursors of Secondary Organic Aerosol (SOA) formation. It has been proven that SOA particles, especially nanosized ones, pose a threat to human health. In this research, experiments with the application of an environmental chamber and real-time measurement techniques were carried out to investigate in...
-
Quantification of unconjugated and total ibuprofen and its metabolites in equine urine samples by gas chromatography–tandem mass spectrometry: Application to the excretion study
PublikacjaIbuprofen (IBU) is a widely used nonsteroidal anti-inflammatory drug (NSAID) in human and also veterinary medicine. NSAIDs are usually highly metabolized compounds in horses; they are often present in equine urine, mostly in their conjugated forms (glucuronides). Thus, hydrolysis to cleave the glucuronide linkage prior to anti-doping analysis is often necessary for improving detection. In this study, unconjugated and total IBU...
-
Influence of Cd(II), Cr(VI) and Fe(III) on early steps of deetiolation process in wheat: fluorescence spectral changes of protochlorophyllide and newly formed chlorophyllide
Publikacja -
Structural and spectroscopic investigation of new luminescent hybrid materials based on calix[4]arene-tetracarboxylate and Ln 3+ ions (Ln = Gd, Tb or Eu)
PublikacjaLanthanide-calixarene hybrid materials are of particular interest due to the combination of the interesting properties of the ligand cavity-like structure and the luminescent features of lanthanides. The aim of this study was to synthesize and investigate the photophysical properties of Eu3+, Tb3+ and Gd3+ hybrids based on calix[4]arene-tetracarboxylate. The preparation of two structurally different...
-
Properties of Charge Carrier Traps in Lu2O3:Tb,Hf Ceramic Storage Phosphors Observed by High-Pressure Spectroscopy and Photoconductivity
Publikacja -
Determination of API content in a pilot-scale blending by near-infrared spectroscopy as a first step method to process line implementation
PublikacjaNear infrared (NIR) spectroscopy was used for estimation of powder blend homogeneity and manufacturing control of a medicinal product powder mixture containing active pharmaceutical ingredient (API). Aiming at initiating a Process Analytical Technology (PAT) activity, the first step was a stationary mode atline evaluation. In this, the content of pharmaceutical active compound in the powder mixtures intended to the direct tabletting...
-
Conformational studies of vasopressin and mesotocin using NMR spectroscopy and molecular modelling methods. Part II: studies in the SDS micelle
Publikacja -
Raman and surface-enhanced Raman spectroscopy investigation of vasopressin analogues containing 1-aminocyclohexane-1-carboxylic acid residue
Publikacja -
The orientational order parameters of a dendritic liquid crystal organo-siloxane tetrapode oligomer, determined using polarized infrared spectroscopy
Publikacja -
Interactions of protons with furan molecules studied by collision-induced emission spectroscopy at the incident energy range of 50–1000 eV
PublikacjaInvestigations of the ion-molecule reactions provide insight into many fields ranging from the stellar wind interaction with interstellar media, up to medicine and industrial applications. Besides the applications, the understanding of these processes is itself a problem of fundamental importance. Thus, interactions of protons with the gas-phase furan molecules have been investigated for the first time in the energy range of 50–1000...
-
The impact of air humidity on the operation of proton exchange membrane fuel cells determined using dynamic electrochemical impedance spectroscopy
PublikacjaThis paper describes the changes in the fuel cell impedance across a range of current loads and humidity changes. The changes of each equivalent circuit parameters representing specific processes occurring in fuel cells, as a function of humidity and current changes, were determined. Within the combined scope of current and humidity, the optimal working conditions of the cells were determined, corresponding to the lowest impedance...
-
A facile method for Tauc exponent and corresponding electronic transitions determination in semiconductors directly from UV–Vis spectroscopy data
PublikacjaIn this work, a facile method allowing for estimation of the exponent in the Tauc equation directly from the UV–vis spectra is presented. It is based on the Taylor expansion of the logarithmic version of the Tauc equation. The Tauc exponent is calculated from the tangent slope of the absorption data. Knowledge of this coefficient provides information about the optical transition types and is used as an input for the calculations...
-
Detection of molecular signatures of oral squamous cell carcinoma and normal epithelium - application of a novel methodology for unsupervised segmentation of imaging mass spectrometry data
Publikacja -
Potential of Serum Proteome Patterns Analysis by MALDI-TOF Mass Spectrometry for Prediction of Acute Radiation Injury Response in Head and Neck Cancers Patients
Publikacja -
Simultaneous determination of hydrophobicity and dissociation constant for a large set of compounds by gradient reverse phase high performance liquid chromatography–mass spectrometry technique
Publikacja -
On the coupling of hydride generation with atmospheric pressure glow discharge in contact with the flowing liquid cathode for the determination of arsenic, antimony and selenium with optical emission spectrometry
Publikacja -
Monitoring the BTEX Volatiles during 3D Printing with Acrylonitrile Butadiene Styrene (ABS) Using Electronic Nose and Proton Transfer Reaction Mass Spectrometry
Publikacja -
Calibration of the thermal desorption-gas chromatography-mass spectrometry system using standards generated in the process of thermal decomposition of chemically modified silica gel
Publikacja -
Application of gas chromatography-mass spectrometry preceded by solvent extraction to determine volatile fatty acids in wastewater of municipal, animal farm and ladfill origin
PublikacjaW ramach przeprowadzonych badań została opracowana metodyka oznaczania lotnych kwasów tłuszczowych (LKT) z próbek ścieków pochodzących z oczyszczalni ścieków komunalnych, farm zwierząt oraz ze składowiska odpadów organicznych, techniką ekstrakcji ciecz-ciecz (LLE) za pomocą eteru metylo-tert-butylowego (MTBE) jako ekstahenta. Dobrano optymalne warunki chromatograficznego rozdzielania i oznaczania LKT w próbkach środowiskowych,...
-
Application of headspace-solid phase microextraction followed by gas chromatography-mass spectrometry to determine short-chain alkane monocarboxylic acids in aqueous samples
PublikacjaCelem prowadzonych badań było opracowanie metodyki oznaczania krótkołańcuchowych kwasów alkanomonokarboksylowych (KKA), opartej na ich izolowaniu i wzbogacaniu za pomocą techniki HS-SPME, a następnie oznaczaniu za pomocą chromatografii gazowej sprzężonej ze spektrometrią mas (GC-MS). Do ekstrakcji zastosowano włókno pokryte polarną fazą stacjonarną opartą na glikolu polietylenowym (PEG). Dla celów porównawczych zastosowano również...
-
Method for the determination of carboxylic acids in industrial effluents using dispersive liquid-liquid microextraction with injection port derivatization gas chromatography–mass spectrometry
PublikacjaThe paper presents a new method for the determination of 15 carboxylic acids in samples of postoxidative effluents from the production of petroleum bitumens using ion-pair dispersive liquid-liquid microextraction and gas chromatography coupled to mass spectrometry with injection port derivatization. Several parameters related to the extraction and derivatization efficiency were optimized. Under optimized experimental conditions,the...
-
Application of dynamic headspace and gas chromatography coupled to mass spectrometry (DHS-GC-MS) for the determination of oxygenated volatile organic compounds in refinery effluents
PublikacjaThe paper presents a new procedure for the determination of oxygenated volatile organic compounds (O-VOCs) in postoxidative effluents from the production of petroleum asphalt using dynamic headspace coupled to gas chromatography-mass spectrometry in the selected ion monitoring (SIM) mode (DHSGC-MS). Among the GC capillary columns tested, a polar SLB-IL111 column with the ionic liquid stationary phase was found to be superior due...
-
Monitoring the BTEX Volatiles during 3D Printing with Acrylonitrile Butadiene Styrene (ABS) Using Electronic Nose and Proton Transfer Reaction Mass Spectrometry
PublikacjaWe describe a concept study in which the changes of concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds and styrene within a 3D printer enclosure during printing with different acrylonitrile butadiene styrene (ABS) filaments were monitored in real-time using a proton transfer reaction mass spectrometer and an electronic nose. The quantitative data on the concentration of the BTEX compounds, in particular...
-
Evaluation of the potential of Microwave Plasma–Atomic Emission Spectrometry for trace elements leaching assessment from the concrete matrix with sewage sludge ash additives
PublikacjaThe management of ash generated during the thermal utilization of sewage sludge is a significant environmental problem requiring an effective technological solution. One alternative way to dispose of sewage sludge is to bind it in concrete as a substitute for part of the aggregate. The properties of the C-S-H phase enable effective immobilization of harmful substances that sewage sludge contains. The amount of individual compounds...
-
Corrosion Inhibition of Aluminium Alloy AA6063-T5 by Vanadates: Local Surface Chemical Events Elucidated by Confocal Raman Micro-Spectroscopy
PublikacjaChemical interactions between aqueous vanadium species and aluminium alloy AA6063-T5 were investigated in vanadate-containing NaCl solutions. Confocal Raman and X-ray photoelectron spectroscopy experiments were utilised to gain insight into the mechanism of corrosion inhibition by vanadates. A greenish-grey coloured surface layer, consisting of V+4 and V+5 polymerized species, was seen to form on the alloy surface, especially on...
-
A BODIPY‐Molecular Rotor in Giant Unilamellar Vesicles: A Case Study by Polarization‐Resolved Time‐resolved Emission and Transient Absorption Spectroscopy
Publikacja -
Application of vibrational spectroscopy, thermal analyses and X-Ray diffraction in the rapid evaluation of the stability in solid-state of ranitidine, famotidine and cimetidine
PublikacjaThis paper reports the study on applicability of Fourier transform infrared (FTIR), near-infrared (NIR) and Raman spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) for the estimation of the chemical stability and photostability of histamine H2-receptor antagonist substances. Ranitidine hydrochloride (RAN), famotidine (FAM) and cimetidine (CIM) were tested and differences in sensitivity were measured...
-
Structural elucidation of transmembrane transporter protein bilitranslocase: Conformational analysis of the second transmembrane region TM2 by molecular dynamics and NMR spectroscopy
Publikacja -
Assessment of the structural evolution of polyimide-derived carbons obtained by phosphoric acid activation using Fourier transform infrared and Raman spectroscopy
Publikacja -
Interaction of Ionomers and Polyelectrolytes with Divalent Transition Metal Cations (Cu2+ and VO2+): A Study by Electron Spin Resonance (ESR) Spectroscopy and Viscosimetry
Publikacja -
The common effect of hydrophobic and electrophilic types of hydration dependent on protonation in the sec-butyloamine/HCl/H2O system studied by FTIR spectroscopy
PublikacjaZbadano hydratację sec-butyloaminy w zależności od pH roztworów wodnych przy pomocy spektoskopii FTIR, z zastosowaniem techniki rozcieńczenia izotopowego HDO w H2O. Dane widmowe poddano analizie przy pomocy ilościowej metody widm różnicowych. Stwierdzono, iż wiązania wodorowe cząsteczek wody tworzących klatratopodobną otoczkę hydratacyjną wokół aminy ulegają wzmocnieniu na skutek oddziaływania z grupą elektrofilową aminy.
-
Anticarcinogenic and antioxidant activities of leaves and flowers hydroalcoholic extracts of Nerium oleander L.: PCA analysis and phytochemical content by FTIR spectroscopy
PublikacjaAims: The aim of this work is the evaluation the anticarcinogenic effect on HT29 cancer cells lines and antioxidant effect of three extracts from different morphological parts (leaves (LE), pink flowers (PFE) and white flowers (WFE)) of Nerium oleander lin. Methods: This research provides the anticarcinogenic activity of extracts from N. oleander white flowers. Principal Component Analysis (PCA) was applied to estimate the relationship...
-
Solvation of cobalt(II) and trifluoromethanesulfonate ions in N,N-dimethylformamide-methanol mixed solvent studied by means of FT-IR spectroscopy
PublikacjaWidma FT-IR roztworów Co(CF3SO3)2-N,N-dimetyloformamid-metanol były analizowane w zakresie pasm CO i OH za pomocą metody widm różnicowych. Wyznaczono liczbę cząsteczek DMF i MeOH w pierwszej sferze solwatacji jonu Co(II) w zależności od składu rozpuszczalnika. Stwierdzono także obecność drugiej sfery solwatacji jonu Co(II) i scharakteryzowano ją ilościowo. Zbadano również solwatację jonu tifluorometanosulfonowego oraz asocjację...
-
Dynamic electrochemical impedance spectroscopy and polarization studies to evaluate the inhibition effect of benzotriazole on copper-manganese-aluminium alloy in artificial seawater
PublikacjaPrzeprowadzono badania wpływu benzotriazolu (BTA) na korozję nowego typ mosiądzu (CMA) w środowisku syntetycznej wody morskiej przy użyciu dynamicznej elektrochemicznej spektroskopii impedancyjnej (DEIS), techniki polaryzacji rezystancyjnej i ekstrapolacji krzywych Tafela. Wyniki pomiarowe otrzymane przy użyciu tych metod wskazują spadek szybkości korozji wraz ze wzrostem stężenia BTA. Wskazuje to na inhibicyjne własności BTA w...
-
Characteristics of hydration water around hen egg lysozyme as the protein model in aqueous solution. FTIR spectroscopy and molecular dynamics simulation
PublikacjaW niniejszej pracy przedstawiono wyniki badań dotyczące hydratacji białka modelowego - lizozymu z jaja kurzego w roztworze wodnym. Wiodącą techniką stosowaną w badaniach była spektroskopia oscylacyjna FTIR z zastosowaniem techniki rozcieńczenia izotopowego wody półciężkiej HDO w roztworze wody zwykłej. Analiza widma HDO przy pomocy "metody widm zaburzonych" pozwoliła na wyizolowanie widma wody zaburzonej przez lizozym, a tym samym...
-
Solid State Conductivity of Optimized Polypyrrole Coatings on Iron Obtained from Aqueous Sodium Salicylate Solution Determined by Impedance Spectroscopy
PublikacjaIn this work the optimization procedure for corrosion resistance, surface analysis and electrical properties of PPy-Fe electrodes have been examined. Polypyrrole (PPy) film was electrochemically synthesized in a one step process from an aqueous solution of sodium salicylate and pyrrole with certain concentrations, different parameters and type of polymerization...
-
Local structural and chemical ordering of nanosized Pt(3±δ)Co probed by multiple-scattering x-ray absorption spectroscopy
PublikacjaThis work reports a detailed investigation of the local structure and chemical disorder of a Pt(3±δ)Co thin film and Pt(3±δ)Co nanoparticles. We have used a combination of techniques including x-ray absorption spectroscopy (XAS), x-ray diffraction (XRD), and high-resolution transmission electron microscopy (TEM). The important effect of chemical ordering on pair and three-atom configurations has been studied using computer simulations...
-
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...
-
Combined chemoresistive and in situ FTIR spectroscopy study of nanoporous NiO films for light-activated nitrogen dioxide and acetone gas sensing
PublikacjaThe chemoresistive sensor response of nanoporous NiO films prepared by advanced gas deposition was investigated by combined resistivity and in situ FTIR spectroscopy, with and without simultaneous light illumination, to detect NO2 and acetone gases. The sensitivity towards NO2 increased dramatically under UV irradiation employing 275 nm light. Improved sensitivity was observed at an elevated temperature of 150 °C. In situ FTIR...