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Wyniki wyszukiwania dla: AMMONIUM IONIC LIQUID, LIQUID MEMBRANE, TOLUENE, SEPARATION, SELECTIVITY
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Calix[4]arenes appended with thioamide moieties as powerful tool for heavy metals recognition
PublikacjaSelectivity of new thioamide derivatives was assessed using those ligands as sensor materials in ion-selective membrane electrodes and tested towards Pb2+ - selectivity. The influence of the nature of the thioamide function (linear, branched or cyclic substituents) on their ionophoric properties was investigated. Electrodes based on cyclic thioamide moieties are promising analytical tools for monitoring Pb2+ concentration in natural...
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Green chromatography
PublikacjaAnalysis of organic compounds in samples characterized by different composition of the matrix is very important in many areas. A vast majority of organic compound determinations are performed using gas or liquid chromatographic methods. It is thus very important that these methods have negligible environmental impact. Chromatographic techniques have the potential to be greener at all steps of the analysis, from sample collection...
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On the Possibility of the Amphotericin B-Sterol Complex Formation in Cholesterol- and Ergosterol-Containing Lipid Bilayers: A Molecular Dynamics Study
PublikacjaAmphotericin B (AmB) is a well-known membrane-active antibiotic that has been used to treat systemicfungal infections for more than 45 years. Therapeutic application of AmB is based on the fact that it is moreactive against ergosterol-containing membranes of fungal cells than against mammalian membranes withcholesterol. In this paper, we examine the hypothesis according to which the selectivity of the AmB's membraneaction originates...
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INVESTIGATION OF ACIDIC SOLUTIONS BY POTENTIOMETRIC TASTE SENSOR WITH ALL SOLID STATE ELECTRODES
PublikacjaPotentiometric taste sensors with electrodes containing lipophilic compound / polymer membranes were already used to distinguish commercial liquid products. In this paper a new potentiometric taste sensor consisting of six All Solid State Electrodes (ASSEs) has been presented. Each of the membrane contains a selected lipophilic compound. The set-up consists of a reference electrode and six ASSEs. The inner layer made of a conducting...
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Thermodynamic interpretation and prediction of CO2 solubility in imidazolium ionic liquids based on regular solution theory
PublikacjaRegular solution theory (RST) is the most popular model for the interpretation of the interaction between CO2 and ionic liquids. In the present work, the parameters of this model were determined for the CO2 absorption in eleven imidazolium ionic liquids. The y-intercept (A) of the RST model for the investigated imidazolium liquids increases with increasing temperature whereas the slope (B) remains constant. The values of RST parameters...
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The Impact of Sloshing Liquids on Ship Stability for Various Dimensions of Partly Filled Tanks
PublikacjaLiquid sloshing phenomenon taking place in partly filled ships' tanks directly affects the stability of a vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation. The paper is focused on a dynamic heeling moment due to liquid sloshing in tanks onboard ships. A number of numerical simulations of liquid...
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New Polymeric Materials for Solid Phase Extraction
PublikacjaSolid phase extraction (SPE) is a popular sample preparation technique, which can be applied directly in gas–solid phase and liquid–solid phase, or indirectly to solid samples by using, e.g., thermodesorption with subsequent chromatographic analysis. Although SPE can be described as a physical extraction process involving a liquid phase and a solid phase, the increased use of packed sorbent formats seems to have led to a bias toward...
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Levels of 13 multi-class pesticide residues in Polish honeys determined by LC-ESI-MS/MS
PublikacjaLevels of 13 pesticides in 40 honey samples form Poland are reported. A rapid and sensitive method was developed for the LC-ESI-MS/MS determination of multi-class pesticide residues in honey samples. Liquid-liquid extraction (LLE) on a diatomaceous earth support (requiring the use of small amounts of organic solvent), followed by chromatographic separation on a C18 column and gradient elution were employed. The method quantifies...
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A new relevant membrane application: CO2 direct air capture (DAC)
PublikacjaSince carbon dioxide (CO2) is the primary greenhouse gas emitted into the atmosphere due to human activities, strong research efforts have been developed towards capturing and decreasing its production. Unfortunately, specific processes and activities make it impossible to avoid CO2 emissions. Among the different strategies scientists propose for CO2 reduction, direct CO2 capture from the atmosphere, also known as direct air capture...
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Analytical procedures for quality control of pharmaceuticals in terms of residual solvents content: Challenges and recent developments
PublikacjaResidual solvents play an important role in the synthesis of drugs and in product formulations. In addition, they pose a serious problem, that is toxicity, as many of them exhibit toxic or environmentally hazardous properties. Therefore, constant monitoring of quality control is needed. In this study, we present an overview of regulatory and general methods described by various pharmacopoeias. Then, the most commonly used methodologies...
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Impact of the Alkyl Side Chains of Cations and Anions on the Activity and Renaturation of Lysozyme: A Systematic Study Performed Using Six Amino‐Acid‐Based Ionic Liquids
PublikacjaThe impact of the structure of ionic liquid on the activity and renaturation of lysozyme from the hen egg white (HEWL) was investigated. A set of six ionic liquids based on morpholinium cation and N-acylated amino acids as anions were exploited. The matrix used was based on two homologous series: one with N-acetyl-L-valinate [Val] as a common anion and morpholinium cation with a different number of...
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Effect of different crystalline structures on W/O and O/W/O wax emulsion stability
PublikacjatThe possibility of emulsion stabilization using mineral and vegetable wax particles only (without sur-factant) was investigated. Mineral waxes, paraffin wax and ceresin, and a vegetable wax, carnauba wax,were used. The content of the wax particles and the water to oil proportion were found crucial for thestability of all emulsions. Some emulsions were also produced with a liquid wax (i.e. jojoba oil). Themultiple light scattering...
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Magnetic deep eutectic solvents as efficient media for extraction of furfural and 5-hydroxymethylfurfural from aqueous samples
PublikacjaThe extraction of furfural (FF) and 5-hydroxymethylfurfural (HMF) from hydrolysates is currently one of the main challenges in bio-refinery. In this work, the separation of FF and HMF from the aqueous phase was carried out using a new type of green solvents – Magnetic Deep Eutectic Solvents (MDES). A conductor-like screening model for realistic solvents (COSMO-RS) was used for the preselection of 400 MDES. MDES which exhibit the...
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Direct-contact condensation from vapour- gas mixture in a spray ejector condenser for negative CO2 power plant
PublikacjaDirect-contact condensation of vapour containing the inert gas on a spray of subcooled liquid exists in a number of technical applications. For example, it may be found in the nuclear industry (e.g. pressurized jet under normal operating conditions, in safety analyses) or in the chemical industry (e.g. mixing-type heat exchanger, degasser, sea water desalting). The problem is also essential to modelling and analysis of some...
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Superhydrophobic sponges based on green deep eutectic solvents for spill oil removal from water
PublikacjaThe paper described a new method for crude oil-water separation by means of superhydrophobic melamine sponges impregnated by deep eutectic solvents (MS-DES). Due to the numerous potential of two-component DES formation, simple and quick screening of 156 non-ionic deep eutectic solvents using COSMO-RS (Conductor-like Screening Model for Real Solvents) computational model was used. DES which were characterized by high solubility...
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Developments in ultrasound-assisted microextraction techniques for isolation and preconcentration of organic analytes from aqueous samples
PublikacjaThe great potential of ultrasonic assistance in sample preparation, especially extraction, is being recognized. In this review, we discuss the applications of ultrasonic radiation in assisting microextraction. Topics covered include ultrasound-assisted emulsification microextraction, ultrasound-assisted-emulsification-dispersive liquid-liquid microextraction, and ultrasound-assisted hollow-fiber liquid-phase microextraction with...
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Preparation and characterization of biopolymeric films with magnetic properties
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The influence of UV-irradiation on the poly(vinyl alcohol)/hyaluronic acid film properties
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The physicochemical properties of 3D materials based on hyaluronic acid modified by tannic acid addition
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The surface photoconductivity in molecular layers
PublikacjaW pracy przedstawiono rezultaty analizy fotoprądów powierzchniowych w cienkich warstwach tetracenu i pentacenu. W szczególności badano wpływ obecności defektów strukturalnych w warstwach na charakterystyki fotoprądów i transport nośników ładunku.
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Electric field dependence of the probability of charge carriers recombination
PublikacjaBadano wpływ zewnętrznego pola elektrycznego na prawdopodobieństwo rekombinacji nośników ładunku w molekularnych ciałach stałych. Przybliżenie analityczne wykazuje, że prawdopodobieństwo to maleje ze wzrostem pola elektrycznego. Otrzymane wyniki mogą być pomocne w wyjaśnieniu spadku wydajności elektroluminescencji w jednowarstwowych diodach elektroluminescencyjnych w zakresie wysokich pól elektrycznych.
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Preparation and characterization of silk fibroin/collagen sponge modified by chemical cross-linking
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Polymer films based on silk fibroin and collagen - the physico-chemical properties
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Physico-chemical properties of three-component mixtures based on chitosan, hyaluronic acid and collagen
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Efficient Extraction of Fermentation Inhibitors by Means of Green Hydrophobic Deep Eutectic Solvents
PublikacjaThe methods for hydrogen yield efficiency improvements, the gaseous stream purification in gaseous biofuels generation, and the biomass pretreatment are considered as the main trends in research devoted to gaseous biofuel production. The environmental aspect related to the liquid stream purification arises. Moreover, the management of post-fermentation broth with the application of various biorefining techniques gains importance....
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Dual functionality of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids: surfactants with catalytic function
PublikacjaA series of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids were synthesized. Acidic hydrogen sulfate ionic liquids with the alkyl chains C6–C14 are characterized by good surface properties. Their surface properties (adsorption and micellization parameters, degree of ionization of micelles, Krafft temperatures and thermodynamic parameters) were determined. Synthesized ionic liquids were applied as a co-catalyst...
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Prototype of electrochemical sensor for measurements of volatile organic compounds in gases
PublikacjaThe paper presents a laboratory prototype of an electrochemical sensor for measurements of volatile organic compounds (VOCs) in gases, utilizing ionic liquids and commercial screen printed electrodes by DropSens. The following ionic liquids have been tested as the electrolyte and redox reaction environment: 1-butyl, 3-methylimidazolium dicyanoamide ([BMIM][N(CN)2]), 1-octyl, 3-methylimidazolium tetrafluoroborate ([OMIM][BF4]),...
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Równolegle przebiegające procesy separacji pianowej jonów Al(III), Cu(II) i Zn(II) z roztworów ich mieszanin
PublikacjaMetody flotacji jonowej i precypitacyjnej należą do procesów separacji pianowej, wykorzystujących zdolność selektywnej adsorpcji niektórych składników roztworu na powierzchni międzyfazowej gaz – ciecz. Do zalet separacji pianowej zalicza się m.in. niewysokie koszty inwestycyjne i eksploatacyjne oraz wysoką skuteczność w obróbce roztworów rozcieńczonych. Celem pracy jest ocena wpływu kluczowych parametrów na wydajność i przebieg...
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Ultrasound-assisted solvent extraction of porous membrane packed solid samples: A new approach for extraction of target analytes from solid samples
PublikacjaFor the first time, a porous membrane-based method is proposed for the extraction of target analytes directly from the solid samples. This method involves the packing of solid sample inside a porous polypropylene membrane sheet whose edges are heat-sealed to fabricate a bag. This bag is immersed in a suitable solvent and the analytes are extracted by the application of ultrasound energy. The various factors that affect the extraction...
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Polysaccharides in fabrication of membranes: A review
PublikacjaSustainability concerns have motivated and directed a great deal of interest over the past decade towards the development of green technologies. Polysaccharides are green polymers, which experienced growing demand to substitute chemically synthetic polymers. Different types of polysaccharides i.e. cellulose-, starch-, chitin- alginate-, and chitosan-based carbohydrate polymers have been applied in the fabrication of separation...
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Determination of dryout localization using a five-equation model of annular flow for boiling in minichannels
PublikacjaDetailed studies have suggested that the critical heat flux in the form of dryout in minichannels occurs when the combined effects of entrainment, deposition, and evaporation of the film make the film flow rate go gradually and smoothly to zero. Most approaches so far used the mass balance equation for the liquid film with appropriate formulations for the rate of deposition and entrainment respectively. It must be acknowledged...
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Chromatographic behavior of a new hybrid type RP material containing silica bonded 1,3-alternate 25,27-bis-[cyanopropyloxy]-26,28-bis-[3-propyloxy]-calix[4]arene
PublikacjaA novel 1,3-alternate 25,27-bis-[cyanopropyloxy]-26,28-bis-[3-propyloxy]-calix[4]arene-bonded silica gel stationary phase (CalixPrCN) was prepared and it's structure was confirmed by ATR-FTIR spectroscopy and elemental analysis. The CalixPrCN phase was characterized in terms of their surface coverage, hydrophobic selectivity, aromatic selectivity, shape selectivity, hydrogen bonding capacity, residue metal content, and silanol...
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Polymeric porous membranes as solid support and protective material in microextraction processes: A review
PublikacjaPolymeric porous membranes have proven to be a versatile and efficient material for microextraction processes. In analytical practice, they are used both as a solid support and as a protective medium for improved sample preparation in various analytical applications. Polymeric porous membranes offer unique advantages in microextraction due to their large surface area and controllable pore size, eliminating interfering effects from...
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Rapid determination of multiple aminoglycoside antibiotics in veterinary formulations by ion-pair chromatography coupled with evaporative light scattering detection
PublikacjaA fast and simple method for simultaneous determination of eight aminoglycoside antibiotics using ion-pairing liquid chromatography (IPLC) coupled with evaporative light scattering detection (ELSD) has been developed and validated. Separation of amikacin, apramycin, gentamicin (as a sum of gentamicin C1, C2 and C1A), kanamycin A, neomycin B, paromomycin, streptomycin and tobramycin was achieved using C18 column with H2O and MeOH/acetone,...
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Nutrient recovery from deammonification effluent in a pilot study using two-step reject water treatment technology
PublikacjaThe aim of this study was to assess the possibility of phosphorus and nitrogen recovery from the liquid fraction of digestates (reject water) pilot study using a two-step technology, where the precipitation of biogenic compounds in the form of magnesium ammonium phosphate (struvite) will be preceded by a deammonification process. The tests confirmed the possibility of nutrient recovery from deammonification effluent. A removal...
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Micellar Route of the Synthesis of Alkyl Xylosides: An Unexpected Effect of Amphiphilic Imidazolium Ionic Liquids
PublikacjaThis manuscript presents results from the investigation on the synthesis of alkyl xylosides by the novel, very efficient and promising protocol of the Fischer synthesis from unprotected xylose and aliphatic alcohol. The use of 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids as the catalysts with dual functionality (surfactant + acid catalyst) and micellar reaction system are the main novelty of described method. It has...
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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...
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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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Solventless and solvent-minimized sample preparation techniques for determining currently used pesticides in water samples: A review
PublikacjaThe intensification of agriculture means that increasing amounts of toxic organic and inorganic compounds are entering the environment. The pesticides generally applied nowadays are regarded as some of the most dangerous contaminants of the environment. Their presence in the environment, especially in water, is hazardous because they cause human beings to become more susceptible to disease. For these reasons, it is essential to...
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Synthesis and application of tetrazole di and triamide derivatives in ion-selective membrane electrodes
PublikacjaA number of tetrazole diamides and triamides have been synthesized and applied as ion carries in ion-selective membrane electrodes. Their selectivity and sensitivity were studied towards alkali, alkaline earth, transition and heavy metal cations. it was found that membranes doped with 3 and 2-nitrophenyl octyl ether exhibit an almost theoretial Nernstian response for NH+ over relatively wide concentration range. Elestrodes with...
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Challenges in determination of pesticides from various chemical groups in fruits and vegetables applying QuEChERS method
PublikacjaPesticides are a large group of compounds with different physical and chemical properties, which place some of them among the most toxic, environmentally stable, and mobile substances. Nevertheless, their number, use, and application are continuously expanding. A consequence of their use is the possible presence of residues in treated food products. To protect consumers from exposure to unacceptable levels of pesticides Maximum...
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Application of gas chromatography–tandem mass spectrometry for the determination of amphetamine-type stimulants in blood and urine
PublikacjaAmphetamine, methamphetamine, phentermine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) are the most popular amphetamine-type stimulants. The use of these substances is a serious societal problem worldwide. In this study, a method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) with simple and rapid liquid-liquid extraction (LLE)...
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A rapid and sensitive method for the quantitative analysis of ibuprofen and its metabolites in equine urine samples by gas chromatography-tandem mass spectrometry
PublikacjaIbuprofen is widely used in human and veterinary medicine for the treatment of chronic pain as well as rheumatic and musculoskeletal disorders. However, t he anal- gesic and anti-inflammatory properties of Ibuprofen have contributed to frequent drug abuse in equestr ian s ports. A sensitive and rapid gas chromatography with tandem mass spectrometry based method with a simple liquid-liquid extraction and deriva- tization requiring...
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Monitoring of volatile organic compounds (VOCs) in atmospheric air. Part I. On-line gas analyzers
PublikacjaThe paper reviews the subject literature concerning the analytical instruments routinely used for monitoring volatile organic compounds in atmospheric air. The analyzers are classified as stationary or mobile according to their ease of transport. Stationary DOAS (Differential Optical Absorption Spectroscopy) analyzer is characterized, as are MIMS (Membrane Introduction Mass Spectrometry), MESI (Membrane Extraction with Sorbent...
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Synthesis and properties of new 'N,'N-phenyltetrazole podand
PublikacjaThe synthesis of a new chromogenic N,N-phenyltetrazole receptor is reported here. The cationbinding properties of this receptor in solution were investigated by naked-eye colour change, electrochemical methods and UV-Vis spectroscopy in various solvents (CH3CN, dimethylsulphoxide (DMSO), DMSO/H2O, CH3CN/H2O and CH3CN/MeOH). In addition, the receptor was used as a sensing material in ion-selective membrane electrodes. The selectivity...
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Measurement of temperature-dependent viscosity and thermal conductivity of alumina and titania thermal oil nanofluids
PublikacjaThe results of simultaneous measurements of dynamic viscosity, thermal conductivity, electrical conductivity and pH of two nanofluids, i.e. thermal oil/Al2O3 and thermal oil/TiO2 are presented. Thermal oil was selected as a base liquid because of possible application in ORC systems as an intermediate heating agent. Nanoparticles were tested at the concentration of 0.1%, 1% and 5% by weight within temperature range from 20°C to...
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Ultrasound-Assisted Solvent Extraction of a Porous Membrane Packed Sample for the Determination of Tobacco-Specific Nitrosamines in the Replacement Liquids for E-Cigarettes
PublikacjaThe content of tobacco-specific nitrosamines (TSNAs) possessing carcinogenic properties has been an important area of research since replacement liquids were introduced for e-cigarettes. A method for determining N′-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT), and N′-nitrosoanabasine (NAB) in replacement liquids for electronic cigarettes was developed using liquid chromatography–tandem...
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Numerical Study of the Impinging Jets Formed by an Injector with Different Nozzle Diameters
PublikacjaThe collision of two or more liquid jets may provide considerable atomisation and efficient mixing of injected substances at the same time. This phenomenon is used, among others, in rocket engines, where the fuel and oxidiser are introduced separately and almost immediately mixed through self-impingement. Depending on the injection and operating conditions, diverse configurations of impinging jets are used, such as doublets,...
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Quality control of cheese samples for the presence of natamycin preservative – A natural deep eutectic solvent (NADES) based extraction coupled with HPLC
PublikacjaA new protocol for the determination of natamycin – an antifungal agent used as a food preservative - in cheese samples – is described. This new method is based on a natural deep eutectic solvent (NADES) green extraction procedure. High-performance liquid chromatography (HPLC) was used for detection and quantification. NADESs with different molar ratios were evaluated for efficient and selective extraction. NADES made of thymol...
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Development and Validation of SPE-HPLC-MS/MS Method for Determining Cyclophosphamide in Surface Waters
PublikacjaA rapid and selective method for trace amounts determination of cyclophosphamide in surface water samples has been developed. A solid phase extraction SPE method for extraction and clean-up procedure has been optimized for determination by reversed-phase high-performance liquid chromatography with tandem mass spectrometry. The analyses proceed in the positive ion mode by means of the electrospray ionization method (ESI). Clean...