Wyniki wyszukiwania dla: THIOCYANATE ION-SELECTIVE ELECTRODES
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Selective detection of F- by chromogenic tetrazole receptor
PublikacjaA chromogenic anion host 4, containing two amide functionalities linked to azo dye and tetrazole rings was synthesized and its complexes with various anions were investigated. The results show that receptor 4 can recognize selectively biologically important F- ion. The binding affinity for F- was investigated by naked-eye colour change, UV-Vis and 1H NMR spectroscopy. Addition F- ion in CH3CN and DMSO to receptor 4 cause a colour...
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Azo and azoxythiacrown ethers: synthesis and properties
PublikacjaA series of 16- and 18-membered azo- and azoxythiacrown ethers have been synthesized by reductive macrocyclization of the respective bis(nitrophenoxy)oxaalkanes. The aromatic residues located in the polyether region of the molecule were introduced to macrocyclic skeletons and their affinities toward different groups of metal cations in ion-selective electrodes were described. X-ray structures for one dinitropodand and one azoxybenzothiacrown...
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Calixthioamides as ionophores for transition and heavy-metal cations
PublikacjaThere is an increasing interest in applying p-tert-butylcalix[4]arenes as sensing materials in ion-selective electrodes(ISEs). Considerable efforts were made to design calixarenes that are selective for some heavy- or transitionmetal ions to be used in ISEs for controlling and monitoring the level of such pollutants in the environment. It has been reported that introduction of softer sulfur atoms instead of oxygen atoms in calix[4]arene...
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Potentiometric taste sensor application for liquid product taste estimation
PublikacjaThe principles of taste sense and kinds of tastes (sweet, salty, sour, bitter, umami and fat) have been described. Food quality estimation by taste sense: organoleptic testing and sensory analysis has been presented. The principle of operation of potentiometric sensor composed of several Ion Selective Electrodes or All Solid State Electrodes with polymeric membranes and macromolecular chemical compounds sensitive to substances...
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TASTE QUALITIES ESTIMATION BY TASTE SENSE AND ELECTROCHEMICAL SENSORS
PublikacjaThe principles of taste sense and kinds of tastes (sweet, salty, sour, bitter, umami and fat) have been described. Food quality estimation by taste sense: organoleptic testing and sensory analysis has been presented. The principle of operation of potentiom etric sensor composed of several Ion Selective Electrodes or All Solid State Electrodes with polymeric membranes and macromolecular chemical compounds sensitive to substances...
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Calix[4]arene-Thioamides as Ionophores for Transition and Heavy Metal cations
PublikacjaCalix[4]arene derivatives play an important role as sensing materials in Ion Selective Electrodes(ISEs). Nowadays a high impact is put to control in natural waters the level of toxic heavy metals, like Pb ,Cd, Hg or Cu which may cause the great risk to human health. Our goal was to design and to synthesize ligands possessing ability to bind transition and heavy metal cations. The synthesis, crystal structures,extractive and ionophoric...
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Rearrangement of azoxybenzocrowns into chromophoric hydroxyazobenzocrowns and the use of hydroxyazobenzocrowns for the synthesis of ionophoric biscrown compounds
PublikacjaThe Wallach rearrangement was used as a method for preparing p-hydroxyazobenzocrown ethers starting from different azoxybenzocrowns as substrates. Synthesis of a series of p-hydroxyazobenzocrowns under modified conditions and characterization of the obtained products are presented. o-Hydroxyazobenzocrowns were identified among the products of the photochemical rearrangement of azoxybenzocrowns. Novel biscrowns were synthesized...
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Application of analytical procedure based on accelerated solvent extraction and ion chromatography technique for determination of thiocyanate and other inorganic ions in human placenta samples
PublikacjaExposure of a pregnant woman during pregnancy is a special case of exposure to toxic substances. Samples of placenta collected for the studies had been prepared with the technique of accelerated solvent extraction and later analyzed for the presence of thiocyanate ion and other inorganic ions, with the use of the technique of ion chromatography. The concentration of thiocyanate ion in placenta samples collected from active smokers...
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Determination of thiocyanate (biomarkers of ETS) and other inorganic ions in human nasal discharge samples using ion chromatography
PublikacjaEnvironmental tobacco smoke (ETS) is a mixture of air and tobacco smoke containing more than 4000 chemical substances. In view of the health risks of many of these substances, studies are needed to determine biomarkers of exposure to ETS constituents in people who actively or passively are exposed to the toxic compounds. The methodologies for determining most biomarkers from saliva, urine and blood samples are known, but methods...
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Composites of tin oxide and different carbonaceous materials as negative electrodes in lithium-ion batteries
PublikacjaAbstract Tin and tin oxide have been considered as suitable materials with high theoretical capacity for lithium ion batteries. Their low cost, high safety and other technical benefits placed them as promising replacements for graphite negative electrodes. The problem to overcome with tin oxide, as well as with other metallic materials, is high volume changes during alloying/dealloying, subsequent pulverization, delamination from...
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Lignin-based carbon fibers for renewable and multifunctional lithium-ion battery electrodes
PublikacjaLignin-based carbon fibers (LCFs) from the renewable resource softwood kraft lignin were synthesized via oxidative thermostabilization of pure melt-spun lignin and carbonization at different temperatures from 1000°C to 1700°C. The resulting LCFs were characterized by tensile testing, scanning electron microscopy (SEM), X-ray diffraction (XRD) and confocal Raman spectroscopy. The microstructure is mainly amorphous carbon with some...
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Studies on 16-membered azothia-and azoxythiacrown ethers as ion carriers in ion selective membranes.
Publikacja16-członowe azo iazoksy korony zawierające w makropierścieniu atomy siarki były badane jako nośniki jonów w jonoselektywnych elektrodach membranowych. Związki te badane były pod kątem kompleksowania metali I i II grupy układu okresowego oraz metali ciężkich i przejściowych. Wyznaczone zostały stałe trwałości kompleksów azokoron z wybranymi kationami za pomocą metody sandwiczowej. W wyniku badań potwierdzono tworzenie się silnych...
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Ionophores in polymeric membranes for selective ion recognition:impedance studies
PublikacjaW pracy badano dwa typy elektrod: membranowe elektrody jonoselektywne (ISE) oraz elektrody nowego typu all-solid-state (AAS). Elektrody AAS zawierają przewodzącą warstwę polimerową na węglu szklistym lub platynie, na który nałożona jest membrana zawierająca jonofor. Do badań użyto dwa jonofory: p-tert-butylokaliks[4]aren-korona-4 (L1) selektywnie kompleksująca jony Na+ oraz kaliks[4]aren-korona-6 (L2) selektywnie kompleksująca...
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Uncertainty of Postmortem Time Estimation Based on Potassium Ion Determination in Vitreous Humor Using Potentiometric Ion-Selective Electrode and Microwave-Induced Plasma with Optical Emission Spectrometry Methods
PublikacjaThere is a need for a reliable and independent evaluation and confirmation of the post-mortem interval (PMI) based on objective factors other than only postmortem changes or temperature measurements. Estimating the PMI by examining the concentration of potassium ions in the vitreous humor (VH) has a tradition in forensic toxicology dating back to the mid-20th century. So far, the methods for determining the presence of potassium...
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Ionophores in polymeric membranes for selective ion recognition; impedance studies
PublikacjaBadania impedancyjne membran zawierających jonofory selektywne na kation Na+ (L1) i Cs+(L2) wykazały, ze stala dielektryczna materiału membrany zależy od typu uzytego plastyfikatora i zmienia się w zakresie od 28 do 60. Rezystancja membran zawierających ligand L1 i L2 wynosi 0.15 -1.4 Mohm w zależności od stężenia elektrolitu zewnnetrznego. Testowona dwa typy elektrod jonoselektywnych: elektrody typu ASS z polimerem przewodzącym...
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Pyrrole azocrown ethers. Synthesis, complexation, selective lead transport and ion-selective membrane electrode studies
PublikacjaOtrzymano nowe, 21-członowe, lipofilowe etery koronowe z jednostką pirolową i dwoma grupami azowymi jako składowymi makrocyklu. Właściwości kompleksujące tych nowych oraz dwóch wcześniej otrzymanych makrocykli zbadano w acetonitrylu. Ligandy te zostały użyte jako jonofory w badaniach konkurencyjnego transportu równomolowej mieszaniny jonów metali: Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Ag2+, Pb2+ w układzie woda(pH 4.9)/chloroform/woda(pH...
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Multifrequency Nanoscale Impedance Microscopy (m-NIM): A novel approach towards detection of selective and subtle modifications on the surface of polycrystalline boron-doped diamond electrodes
PublikacjaIn this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a combination of contact-mode atomic force microscopy with local impedance measurements. The postulated approach is based on the application of multifrequency voltage perturbation instead of standard frequency-by-frequency analysis, which among others offers more time-efficient and accurate determination of the resultant impedance spectra...
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Selective Synthesis of Magnetite Nanospheres with Controllable Morphologies on CNTs and Application to Lithium‐Ion Batteries
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Comparison of Fluoride Ion-Selective Electrode Based Potentiometric Methods of Fluoride Determination in Human Urine
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Selectivity of lithium electrodes: correlation with ion-ionophore complexstability constants and with interfacial exchange current densities
PublikacjaMembranowe elektrody selektywne na jony litu oparte na dwóch różnych dicyk-lohesyloamidowych jonoforach poddane zostały systematycznym badaniom. Potencjometrycznie wyznaczono wartości współczynników selektywności. Wartości stałych trwałości kompleksów z jonami litu, sodu i potasu wyznaczono metodą membran "sandwichowych". Transfer ładunków przez membranę oraz przez granicę faz membrana/roztwór badano metodą spektroskopii impedancyjnej....