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Search results for: microextraction techniques
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Evolution of magnetic and transport properties in (Cr1−xMnx)2AlC MAX-phase synthesized by arc melting technique
PublicationHerein we initiate a comeback to the arc melting technique to produce MAX-phase solid solutions. Bulk samples of (Cr1−xMnx)2AlC MAX-phase with X = 0, 0.025, 0.05 and 0.1 were synthesized and studied by means of X-ray diffractometry, scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy. Samples were established to be homogeneous with an incorporation of Cr7C3, AlCr2 and Al2O3 secondary phases which...
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Assessment of the impact of jet impingement technique on the energy efficiency of air-cooled BIPV/T roof tile
PublicationThe paper concerns a numerical analysis of cooling of the hybrid photovoltaic (PV) modules dedicated to Building-Integrated Photovoltaic/Thermal (BIPV/T) systems. Attention was focused on the photovoltaic roof tiles, using a jet impingement technique, in which the intensification of heat transfer is ensured by streams of air hitting the heat exchange partition. A series of numerical simulations were carried out to assess an influence...
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Energy-Efficient Self-Supervised Technique to Identify Abnormal User Over 5G Network for E-Commerce
PublicationWithin the realm of e-commerce networks, it is frequently observed that certain users exhibit behavior patterns that differ substantially from the normative behaviors exhibited by the majority of users. The identification of these atypical individuals and the understanding of their behavioral patterns are of significant practical significance in maintaining order on e-commerce platforms. One such method for accomplishing this objective...
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Magnetic hydrophobic deep eutectic solvents for orbital shaker-assisted dispersive liquid-liquid microextraction (MAGDES-OS-DLLME) - determination of nickel and copper in food and water samples by FAAS
PublicationIn this work, a cheap and widely applicable dispersive liquid-liquid microextraction (DLLME) method was developed for the extraction of Ni(II) and Cu(II) from water and food samples and analysis using flame atomic absorption spectrometry. DLLME was assisted by orbital shaker, while ferrofluid as an extractant was based on deep eutectic solvent (DES). This ferrofluid was made of hydrophobic DES (hDES), composed of lauric acid and...
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Application and optimization of headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography - flame-ionization detector (GC-FID) to determine products of the petroleum industry in aqueous samples
PublicationA simple and solvent-free analytical method has been optimized for the determination of hydrocarbons (C6 - C20) from products of the petroleum industry in aqueous samples. Extraction and analysis was carried out using headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled with flame-ionization detector (GC-FID). A ZB-5 capillary column (30 m × 0.25 mm inner diameter, 0.25 µm film thickness) was used for...
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Nowe rozwiązania metodyczne i techniczne w zakresie techniki mikroekstrakcji do fazy stracjonarnej
PublicationSample preparation has been recognized as a critical step of the analytical process, being even considered as the bottleneck of the overall process. Enrichment of target compounds, transfer of the analytes into a solvent compatible with the analytical instrumentation, minimization of potential interferences, and efficient sample clean-up, are among the main aims of sample preparation techniques. In this regard, liquid-liquid extraction...
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Chemical and biological characterization of Ocimum basilicum L. phenolic extract and essential oil derived through ultrasound and microwave-assisted extraction techniques
PublicationPlant-derived bioactive molecules are increasingly utilized in food processing as natural additives, driven by a growing interest in healthier lifestyles. This trend has spurred industries to reformulate products to meet the demands of health-conscious consumers. This study investigates the phenolic extract and essential oil of O. basilicum L. obtained via ultrasound-assisted extraction and microwave-assisted extraction, respectively. Characterization...
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Microcrack monitoring and fracture evolution of polyolefin and steel fibre concrete beams using integrated acoustic emission and digital image correlation techniques
PublicationThe use of polymer and steel fibres in plain concrete appears to be an excellent solution for limiting crack propagation and improving the post-ductility performance of concrete structures. Based on this premise, this study investigated the fracture evolution of polyolefin fibre-reinforced concrete (PFRC) and steel fibre-reinforced concrete (SFRC) specimens through the integrated application of two diagnostic techniques, acoustic...
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Application of different building representation techniques in HEC-RAS 2-D for urban flood modeling using the Toce River experimental case
PublicationThis paper presents the impact of the choice of building representation techniques and hydrodynamic models on urban flood simulations using HEC-RAS 2-D for the Toce River physical model. To this end, eight numerical models based on previous laboratory experiments were prepared to simulate unsteady urban flooding on each side of building units. Two simplified building layouts (aligned and staggered) were examined, where models were...
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Study of effect of phosphate and uranium ions on the thermal properties of surfactant-modified natural red clay using TG–FTIR–MS techniques
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PCA and multidimensional visualization techniques united to aid bioindication of elements from transplanted Sphagnum palustre moss exposed in the Gdańsk city area
PublicationPrzedstawiono wyniki badań zanieczyszczenia atmosfery w Gdańsku za pomocą oznaczeń 18 metali ciężkich w martwych i żyjących mchach Spagnum palustre. Mchy były eksponowane w 12 punktach miasta, a oznaczenia metali przeprowadzono techniką analizy neutronowej. Celem pracy było zbadanie: przydatności żywych i martwych mchów do biokumulacji metali, zanieczyszczenia poszczególnych dzielnic Gdańska metalami ciężkimi oraz narażenia mieszkańców...
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Comparative study on fracture evolution in steel fibre and bar reinforced concrete beams using acoustic emission and digital image correlation techniques
PublicationIn recent decades, the demand for sustainable construction practices has increased, but raw materials such as reinforcing steel remain scarce. Therefore, steel fibres have emerged as a popular and sustainable choice in the construction industry, offering a cost-effective alternative to traditional steel bar reinforcement for both flatwork and elevated structures. The purpose of this study is therefore to compare the performance...
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“Green” nature of the process of derivatization in analytical sample preparation
PublicationNowadays, the idea of Green Analytical Chemistry (GAC) is of high importance what impacts on the rapid growth in the sample preparation area with special emphasis on sample preparation simplification, miniaturization, and automation. Because the derivatization process is often an essential element of the analytical procedure, it should be important to focus on this issue from GAC perspective and conduct a series of experiments...
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Analytical applications and physicochemical properties of ionic liquid-based hybrid materials: A review
PublicationIonic liquids with their unique properties found so far numerous analytical applications. Among them ionic liquids immobilized on the surface or within the pores of a solid support were successfully utilized in extraction techniques dedicated to preconcentration of the analytes from food, environmental and biological samples. In this review we focus on comprehensive summarizing of available literature data on the examples of ionic...
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STAPS-Sciences et Techniques des Activites Physiques et Sportives
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Revue Roumaine des Sciences Techniques-Serie Electrotechnique et Energetique
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Exploring multi-step glucose oxidation kinetics at GOx-functionalized nanotextured gold surfaces with differential impedimetric technique
PublicationFor a few past years, we can observe the enormous growth of investigations related to ultrasensitive electrochemical sensors capable of reliable determination of important body parameters and analytes. Utilized procedures rely on standard electrochemical methods, demanding electrode polarization, and information about the initial characteristics of the working electrode. More and more complex electrode materials are characterized...
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Mechanical Properties and Wear Susceptibility Determined by Nanoindentation Technique of Ti13Nb13Zr Titanium Alloy after “Direct Laser Writing”
PublicationLaser treatment has often been applied to rebuild the surface layer of titanium and its alloys destined for long-term implants. Such treatment has always been associated with forming melted and re-solidified thin surface layers. The process parameters of such laser treatment can be different, including the patterning of a surface by so-called direct writing. In this research, pulse laser treatment was performed on the Ti13Nb13Zr...
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Evaluation of structural and electrical properties of multicomponent spinel oxide thin films deposited via spray pyrolysis technique
PublicationThis work reports the preparation of (Mn,Co,Fe,Ni,Cr)3O4 high-entropy spinel oxide in the form of a ~ 500 nm thin film utilising a facile spray pyrolysis technique. The structural and electrical properties of the layers were characterised after exposure to temperatures in the range of 400–900 ◦C. The as-deposited layers were amorphous, and crystallised upon heat treatment at 500 ◦C. Microstructural analyses proved a homogeneous...
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The Osteopontin Tissue Level as a Breast Cancer Biomarker in Females After Mastectomy Measured by the Capillary Gel Electrophoresis Technique
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Bioactive monolithic composites of silica/polydimethylsiloxane/calcium phosphate obtained at room temperature in sol–gel micromolding technique
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A Subspace-Splitting Moment-Matching Model-Order Reduction Technique for Fast Wideband FEM Simulations of Microwave Structures
PublicationThis article describes a novel model-order reduction (MOR) approach for efficient wide frequency band finite-element method (FEM) simulations of microwave components. It relies on the splitting of the system transfer function into two components: a singular one that accounts for the in-band system poles and a regular part that has no in-band poles. In order to perform this splitting during the reduction process, the projection...
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Identification of pollutants at the adjacent areas to the landfill site using two dimensional gas chromatography with mass spectrometry technique
PublicationMunicipal landfills are considered one of the main sources of air pollutants. In this article is presented the use of a modern analytical technique: a two dimensional gas chromatography to identify the substances in the atmospheric air near a waste processing plant located in Gdansk. In order to determine the types of substances occurring in different atmospheric conditions, the study was conducted from February to April 2016....
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A Mesh Deformation Technique Based on Solid Mechanics for Parametric Analysis of High-Frequency Devices With 3-D FEM
PublicationIn this paper, a versatile technique for mesh defor- mation is discussed, targeted at the electromagnetic (EM) field simulation of high-frequency devices using the 3-D finite element method (FEM). The approach proposed applies a linear elasticity model to compute the displacements of the internal mesh nodes in 3-D when the structure geometry is changed. The technique is compared with an alternative approach...
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Efficient FPGA Implementation of an RFIR Filter Using the APC–OMS Technique with WTM for High-Throughput Signal Processing
PublicationNowadays, Finite Impulse Response (FIR) filters are used to change the attributes of a signal in the time or frequency domain. Among FIR filters, a reconfigurable filter has the advantage of changing the coefficient in real-time, while performing the operation. In this paper, the Anti-Symmetric Product Coding (APC) and Odd Multiple Storage (OMS) modules are utilized to implement the reconfigurable FIR filter (RFIR–APC–OMS). Herein,...
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Highly efficient maximum power point tracking control technique for PV system under dynamic operating conditions
PublicationThe application of small-scale electrical systems is widespread and the integration of Maximum Power Point Tracking (MPPT) control for Photovoltaic systems with battery applications further enhances the techno-economic feasibility of renewable systems. For this purpose, a novel MPPT control system using Dynamic Group based cooperation optimization (DGBCO) algorithm is utilized for PV systems. The population in the DGBCO is divided...
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Analysis of waveguide junctions containing axially-symetrical posts using hybrid finite-difference mode-matching technique
PublicationArtykuł opisuję hybrydową metodę analizy złącz falowodowych zawierających osiowo-symetryczne obiekty rozpraszające. Metoda jest oparta na metodzie dopasowania rodzajów oraz metodzie różnic skończonych w dziedzinie częstotliwości.
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The research on properties of asphaltene stationary phase to separate mixtures of optically active compounds with the use of gas chromatography technique
PublicationW pracy przedstawiono wyniki badań nad możliwością zastosowania asfaltenów jako chiralnej fazy stacjonarnej do chromatografii gazowej. Wyniki uzyskane dla fazy asfaltenowej porównano z wynikami uzyskanymi poprzez zastosowanie komercyjnie dostępnej chiralnej fazy stacjonarnej. Badania wykazały, że frakcja asfaltenowa posiada właściwości umożliwiające uzyskanie rozdzielenia mieszanin związków optycznie czynnych.
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Titania Nanotubes/Hydroxyapatite Nanocomposites Produced with the Use of the Atomic Layer Deposition Technique: Estimation of Bioactivity and Nanomechanical Properties
PublicationTitanium dioxide nanotubes/hydroxyapatite nanocomposites were produced on a titanium alloy (Ti6Al4V/TNT/HA) and studied as a biocompatible coating for an implant surface modification. As a novel approach for this type of nanocomposite fabrication, the atomic layer deposition (ALD) method with an extremely low number of cycles was used to enrich titania nanotubes (TNT) with a very thin hydroxyapatite coating. X-ray diffraction (XRD)...
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Optimization of the spindle speed during milling of large-sized structures with the use of technique of Experiment-Aided Virtual Prototyping
PublicationIn the paper are presented considerations concerning vibration suppression problems during milling of large-sized workpieces with the use of innovative method of matching the spindle speed of cutting tool. It depends on repeatable change of the spindle speed value as soon as the optimal vibration state of the workpiece approaches. The values of dominant “peaks” in the frequency spectra and the Root Mean Square (RMS) values of time...
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Utilization of glass fibres as supports for surface compounds for generation of gaseous standard mixtures using thermal decomposition technique
PublicationPrzy oznaczaniu analitów na śladowym lub ultraśladowym poziomie stężeń, szczególnie w przypadku próbek o złożonym lub niejednorodnym składzie matrycy, analityk napotyka dodatkowe trudności techniczne i metodyczne związane z walidacją stosowanych procedur. Niezbędne jest zatem dysponowanie odpowiednimi wzorcami (lub lepiej materiałami odniesienia), które swoim składem są jak najbardziej zbliżone do składu próbek rzeczywistych. W...
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A comprehensive lipidomic analysis of oilseeds using LC-Q-TOF-MS and dispersive micro-solid phase (D-μ-SPE) extraction techniques
PublicationGrowing public health awareness increased the demand for natural products with positive health benefits. Vegetable oils containing omega-3 fatty acids (FA) such as alpha-linolenic acid (ALA) has been proposed as a possible source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In this work, a comprehensive lipidome analysis and comparison of seven oilseeds, including flaxseed, chia, hemp, black cumin, white sesame,...
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Urban flash flood hazard identification and assessment applying geospatial techniques and hydrodynamic modeling; Erbil city case study, Kurdistan Region of Iraq
PublicationThis dissertation aims to investigate the factors behind flash flooding in Erbil's central district, located in the Kurdistan Region of Iraq, and develop a methodology for assessing flood hazards in the city, despite limited data accessibility. In this thesis, each factor was investigated, including analyzing extreme precipitation events in the last two decades, including their spatial and temporal distribution of rainfall, intensity,...
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Spatiotemporal Assessment of Satellite Image Time Series for Land Cover Classification Using Deep Learning Techniques: A Case Study of Reunion Island, France
PublicationCurrent Earth observation systems generate massive amounts of satellite image time series to keep track of geographical areas over time to monitor and identify environmental and climate change. Efficiently analyzing such data remains an unresolved issue in remote sensing. In classifying land cover, utilizing SITS rather than one image might benefit differentiating across classes because of their varied temporal patterns. The aim...
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Comparison of two infant chest compression techniques during simulated newborn cardiopulmonary resuscitation performed by a single rescuer: A randomized, crossover multicenter trial
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Least absolute shrinkage and selection operator and dimensionality reduction techniques in quantitative structure retention relationship modeling of retention in hydrophilic interaction liquid chromatography
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Identification of Shift in Sowing and Harvesting Dates of Rice Crop (L. Oryza sativa) through Remote Sensing Techniques: A Case Study of Larkana District
PublicationThe present study aimed to determine the impact of climate variability on rice crops in terms of sowing and harvesting dates and crop period. The identification of sowing and harvesting dates were spotted by mask identification, variations in land surface temperature (LST) on a temporal scale in the respective months, and a field-level social inquiry. The study was conducted during a time period (1994–2017), in which geo-referenced...
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The determinants of morphology and properties of the nanohydroxyapatite coating deposited on the Ti13Zr13Nb alloy by electrophoretic techniqe
PublicationThe titanium and its alloys belong at present to the most preferred and commonly applied biomaterials for load- bearing implants. The surfaces of biomaterials are subjected to modification, including the hydroxyapatite coatings deposited in order to ensure corrosion resistance and better joining between an implant and a bone through the possibility of ingrowth bone into the coating. In this paper, the morphology and properties...
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Nanoconfined Ionic Liquids. Properties and analytical applications
PublicationThe synergistic combination of ionic liquids (ILs) and solid‐like matrices involves a powerful coupling towards the development of new sustainable analytical methodologies. Here we survey the literature regarding such ionic liquid‐based hybrid materials, including a database on relevant physicochemical properties of ionic liquids confined in a solid network. Furthermore, this chapter presents the strategies implemented to combine...
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Application of Headspace Solid-phase Microextraction with Poly(1-vinyl-3- Hexylimidazolium Chloride) Polymeric Ionic Liquid Coating using GC - MS to Determine Volatile Fatty Acids in Dairy Wastewater
PublicationVolatile fatty acids were determined in this study using headspace solid-phase microextraction (HS-SPME) with a poly(1-vinyl-3-hexylimidazolium chloride) polymeric ionic liquid coated fiber followed by gas chromatography - mass spectrometry. Experimental parameters such as extraction time and temperature, sample volume as well as desorption time and temperature were optimized. Detection limits of the method were in the range of...
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Extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a neonatal unit: control of an outbreak using a new ADSRRS technique
PublicationSzczepy Klebsiella pneumoniae (EPKP)produkujące beta-laktamazy o rozszerzonym spektrum substratowym (ESBL)stanowią często problem zakażeń na oddziałach noworodkowych. Izolaty od 149 pacjentów poddano typowaniu nową metodą opartą na zjawisku supresji PCR, ADSRRS-fingerprinting, wykazując pochodzenie klonalne badanych szczepów. Użyteczność techniki ADSRRS-finerprinting została potwierdzona innymi metodami - RAPD i PFGE.
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Monolithic polydimethylsiloxane-modified silica composites prepared by a low-temperature sol–gel micromolding technique for controlled drug release
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Impact of sensitization on dissolution process of AISI 304 stainless steel during intergranular corrosion evaluated using DEIS technique
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A technique of experiment aided virtual prototyping to obtain the best spindle speed during face milling of large-size structures
PublicationThe paper presents an original method concerning vibration suppression problem during milling of large-size and geometrically complicated workpieces with the use of novel way of selecting the spindle speed. This consists in repetitive simulations of the cutting process for subsequent values of the spindle speed, until the best vibration state of the workpiece is reached. An appropriate method of obtaining a computational model,...
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Verification of the homogeneity of the matrix/analyte mixture on sample plate using MALDI-MS technique and new ionic liquid matrices
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Analysis of pesticide residue in tomato samples using analytical protocol based on application of QuEChERS technique and GC-ECD system
PublicationQuEChERS sample preparation method was used for the determination of 10 pesticides and their metabolites in tomato samples, coupled to gas chromatography with electron capture detector (GCECD). The experimental parameters including oven temperature program, amount of the sample and purifying agent were optimized. The GC-ECD method was validated in terms of linearity, selectivity and recovery. The limits of detection (LODs) of the...
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Study on surface termination of boron-doped diamond electrodes under anodic polarization in H2SO4 by means of dynamic impedance technique
PublicationAnodic 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...
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Purification and recovery of laccase produced by submerged cultures of Trametes versicolor by three-phase partitioning as a simple and highly efficient technique
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Identification of predicted genes expressed differentially in pituitary gland tissue of young growing bulls revealed by cDNA-AFLP technique
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Estimation of platinum in environmental water samples with solid phase extraction technique using inductively coupled plasma mass spectrometry
PublicationZoptymalizowano metodykę oznaczania śladowych poziomów stężeń platyny (IV) w oparciu o technikę ekstrakcji do fazy stałej w połączeniu ze spektrometrią mas z plazmą wzbudzoną indukcyjnie. Na etapie wzbogacania platyny wykorzystano żel krzemionkowy modyfikowany grupami aminopropylowymi. Ilościowy odzysk platyny uzyskano poprzez wykorzystanie 1.0 mol L-1 roztworu tiomocznika jako eluenta. Odchylenie standardowe wyników (RSD) było...