The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
H. N. Aliyu - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Characterization of Some Tris (resorcinato) metal (II) Complexes
2011Co-Authors: H. N. Aliyu, M. MustaphaAbstract:The synthesis of sodium tris(resorcinato)metal (II) complexes have been carried out. Solubility, decomposition temperature and infrared (IR) studies were used in characterizing the compounds. The Potentiometric Analysis of the complex compounds shows 1:3 metal to ligand ratio, indicating dibasic behaviour of resorcinol
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Spectroscopic and Potentiometric Analysis on Diaquo Bis (N-2-Amino-3-Methylbutayl-2,4-Pentanedionato) Copper (II) Complex
2010Co-Authors: H. N. Aliyu, I BelloAbstract:A Schiff base was prepared from the reaction of 2 - amino - 3 - methylbutanoic acid and 2, 4 - pentanedione. The reaction of the prepared Schiff base with ethanolic solution of copper (II) chloride formed diaquo bis( N - 2 - amino - 3 - methylbutyl - 2, 4 - pentanedionato) copper (II) complex. The Schiff base is crystalline orange yellow, has a yield of 53% and melting point of 210 o C. The copper (II) Schiff base complex is crystalline greenish blu e, has a yield of 73% and a decomposition temperature of 231 o C. The Schiff base is soluble in most solvent inc luding water, but insoluble in ether. The diaquo bis( N - 2 - amino - 3 - methylbutyl - 2, 4 - pentanedionato) copper (II) complex is soluble in water, DMSO and DMF, but insoluble in most common organic solvents. The molar conductance of the copper (II) Schiff base complex determined is 33 ohm -1 cm 2 mol -1 . The infra-red spectral data sho wed bands in the range 1612 - 1636 and 1592 - 1624cm -1 , assignable to v(C= N) stretching vibrations of the Schiff base and its copper (II) complex, respectively. The broad bands in the range 3278 - 3423 and 3314 - 3397cm -1 are att ributable to v(O-H) stretching frequencies in the Schiff base and it complex compound, respectively. The weak bands at 514 and 387 cm -1 are attributable to v(Cu -O) and v(Cu-N) stretching vibrations, respectively in the copper (II) Schiff base complex. The dissociation constant (pKa) of N - 2 - amino - 3 - methylbutyl - 2, 4 - pentanedione schiff base determined is 4.55. The stability constant and Gibb's free energy of copper (II) Schiff base complex determined are 3.9x10 9 and -5.46x10 4 Jmol -1 , respectively. The ratio of copper (II) ion to N - 2 - amino - 3 - methylbutyl - 2, 4 - pen tanedione determined is 1:1.
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Synthesis and Characterization of N, N' - Bis(Benzoin)-o- phenylenediiminato Zinc (II) Complex
2009Co-Authors: H. N. Aliyu, H. J. AbdullahiAbstract:N, N' - bis(Benzoin)-o-phenylenediimine was synthesized by the treatment of methanolic solution of benzoin with methanolic solution of o-phenylenediimine. Interaction of the ethanolic solution of the Schiff base with the ethanolic solution of zinc (II) chloride yielded the complex compound, N, N' - bis(Benzoin)-o-phenylenediiminato zinc (II). The zinc (II) complex was characterized by infrared spectral studies, potentiometry and conductivity. The complex compound is soluble in acetone but slightly soluble in most organic solvent such as methanol, ethanol nitromethane, chloroform, benzene etc. The complex decomposes at 139 o C, indicating that the complex compound is very stability. The Potentiometric Analysis of the zinc (II) Schiff base complex revealed 1:1 metal to ligand ratio, which corresponds to a four coordinate complex.
Hazem M Abushawish - One of the best experts on this subject based on the ideXlab platform.
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a mercury ii selective sensor based on n n bis salicylaldehyde phenylenediamine as neutral carrier for Potentiometric Analysis in water samples
Journal of Hazardous Materials, 2009Co-Authors: Hazem M AbushawishAbstract:Mercuric ions in water samples were determined by a new modified carbon paste electrode based on N,N′-bis(salicylaldehyde)-phenylenediamine (salophen) as a chemical modifier. The construction, performance, and applications of mercury carbon paste electrode are described. The electrode displays a linear log [Hg2+] versus EMF response over a wide concentration range of 3.2 × 10−7 to 3.2 × 10−4 with Nernstian slope of 58.8 ± 0.3 mV/decade with limit of detection 1.5 × 10−7 over the pH range 3.8–7.8; the presence of the complex Hg(OH)+ ion explains the slope of the response curve. The proposed sensor shows a reasonable discrimination ability towards Hg(II) in comparison to some alkali, alkaline earth transition and heavy metal ions. The modified electrode was applied as indicator electrode in Potentiometric titration and successfully used to determine mercury(II) in water samples with satisfactory results.
Tunde Toth - One of the best experts on this subject based on the ideXlab platform.
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fast Potentiometric Analysis of lead in aqueous medium under competitive conditions using an acridono crown ether neutral ionophore
Sensors, 2018Co-Authors: Adam Golcs, Viola Horvath, Peter Huszthy, Tunde TothAbstract:Lead is a particularly toxic heavy metal that is present above acceptable levels in the water of many countries. This article describes a quick detection method of lead(II) ions using a polyvinyl chloride (PVC)-based ion-selective membrane electrode containing an acridono-crown ether ionophore by potentiometry. The electrochemical cell exhibits a Nernstian response for lead(II) ions between the concentration range of 10−4 to 10−2 M, and can be used in the pH range of 4–7. The applicability of this sensor was verified by measuring a multicomponent aqueous sample. Under the given conditions, this electrode is suitable for the selective quantitative Analysis of lead(II) ions in the presence of many additional metal ions.
Erno Pretsch - One of the best experts on this subject based on the ideXlab platform.
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The new wave of ion-selective electrodes
Trends in Analytical Chemistry, 2007Co-Authors: Erno PretschAbstract:During the last decade, the capabilities of Potentiometric Analysis have changed fundamentally in that the lower limit of detection (LOD) of ion-selective electrodes (ISEs) has improved by a factor of up to one million and the discrimination factor of interferences from ions by up to one billion. These spectacular improvements are related to the control of ion fluxes through the ion-selective membrane. Nowadays, ISEs can be used for trace measurements in environmental samples. Furthermore, by reducing the volume of the samples, the LOD in terms of the amount of analytes has been reduced to the attomole range. This is promising for bioAnalysis using metal nanoparticle labels. Other recent progress includes the excellent fundamental understanding of the working mechanism, the introduction of a novel kind of calibration procedure that reduces the demands on signal stability and reproducibility, and the advent of pulsed amperometric methods.
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a novel polymeric membrane electrode for the Potentiometric Analysis of cu2 in drinking water
Analytica Chimica Acta, 2005Co-Authors: Zsofia Szigeti, Istvan Bitter, Klara Toth, Christopher Latkoczy, Daniel Fliegel, Detlef Gunther, Erno PretschAbstract:Abstract Based on a novel ionophore, an ion-selective electrode has been developed for the determination of Cu 2+ in drinking water. Its selectivity behavior is characterized and its lower detection limit optimized for measurements with different electrolyte backgrounds. The lower detection limit was 2 × 10 −9 M Cu 2+ for samples with low ionic background and 1 × 10 −7 M Cu 2+ with ionic background typically found in drinking water.
Patrick Sharrock - One of the best experts on this subject based on the ideXlab platform.
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Acrylophosphonic acid reactivity with calcium ions and biological apatite
Dental Materials, 2008Co-Authors: Marie A. Bayle, Gwendoline Gregoire, Kashif Nasr, Patrick SharrockAbstract:Objectives: Acrylophosphonic acid (H2L) was reacted with biological apatite originating from dental enamel powder in order to identify and study the reaction products formed during the use of self-etch monomers. Nuclear magnetic resonance spectroscopy (NMR) showed the formation of brushite and a calcium salt of acrylophosphonic acid. This Ca salt was further synthesized and characterized by NMR, Fourier transform-infrared (FT-IR) and chromatography coupled with Potentiometric Analysis. The results reveal that calcium ions form a compound with two mono-deprotonated acrylophosphonate anions at physiological pH values. Thus, dissolution of the biological apatite by the acid-etch releases phosphate and calcium ions that combine to form brushite. The remaining dissolved Ca neutralize the acrylophosphonic acid to form an ionic salt of formula Ca(HL)2. Significance: The stoichiometry of this calcium salt allows us to conclude that, following a self-etch procedure, dissolved Ca ions participate in the formation of crosslinks in the complex photopolymerized copolymer composite network of the hybrid layer. © 2007 Academy of Dental Materials.