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2003

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Simultaneous Determination Of Copper, Zinc And Selenium In Chicken Liver By Differential Pulse Polarography, Güler Ekmekci̇, Güler Somer, Olcay Şendi̇l Jan 2003

Simultaneous Determination Of Copper, Zinc And Selenium In Chicken Liver By Differential Pulse Polarography, Güler Ekmekci̇, Güler Somer, Olcay Şendi̇l

Turkish Journal of Chemistry

A differential pulse polarographic method for the determination of copper, zinc and selenium in chicken liver is described. It was possible to determine these elements in a single sample solution after acid digestion. Dried liver samples weighing about 3 g were digested using HNO_{3} and HClO_{4} acids. Britton-Robinson or acetate buffer has been found suitable as the supporting electrolyte. For the determination of selenium, the hydrogen catalytic peak was used after the addition of molybdenum(VI) to the buffer solution at about pH 3. Then the pH of the same solution was increased to 4 and zinc was determined. For the …

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Production Of Bacterial Polyesters From Some Various New Substrates By Alcaligenes Eutrophus And Pseudomonas Oleovorans, Hali̇l Koçer, Mehli̇ka Borcakli, Songün Demi̇rel, Baki̇ Hazer Jan 2003

Production Of Bacterial Polyesters From Some Various New Substrates By Alcaligenes Eutrophus And Pseudomonas Oleovorans, Hali̇l Koçer, Mehli̇ka Borcakli, Songün Demi̇rel, Baki̇ Hazer

Turkish Journal of Chemistry

Poly(3-hydroxy alkanoate)s (PHA)s are bacterial polyesters that have, due to their biodegradability and biocompatibility, attracted considerable industrial interest. All the substrates used in feeding Alcaligenes eutrophus and Pseudomonas oleovorans have been reviewed as far as we know, and some more new substrates or mixtures have been used in PHA production by microorganisms. Alcaligenes eutrophus was fed with 4-pentenoic acid, 2-hydroxy ethyl methacrylate (HEMA), corn oil acids, linseed oil acids and limonene as well as mixtures of acetic acid and glucose or lactose. Either HEMA as a sole carbon source or the mixture of glucose did not produce polyester; limonene as …

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Aluminum Fractionation In The Water Of Karakaya Dam Lake (Malatya, Turkey), F. Zehra Küçükbay, Mustafa Demi̇r Jan 2003

Aluminum Fractionation In The Water Of Karakaya Dam Lake (Malatya, Turkey), F. Zehra Küçükbay, Mustafa Demi̇r

Turkish Journal of Chemistry

A method was developed for the determination of trace amounts of Al species in water samples using the amberlite type XAD-4 resin. For this purpose, total dissolved Al, organically bonded Al and particulate Al in water samples taken from Karakaya dam lake (Malatya, Turkey) were determined by flame atomic absorption spectroscopy (FAAS) or graphite furnace atomic absorption spectroscopy (GFAAS) after an enrichment procedure. The total dissolved Al in the water samples was determined using 8-hydroxyquinoline as complexing reagent at pH 8 and amberlite type XAD-4 resins for the enrichment. The organically bonded Al species in the water samples were destroyed …

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Atomic Absorption And Spectrophotometeric Determinations Of Salicylhydroxamic Acid In Its Pure And Pharmaceutical Dosage Forms, Alaaeldin Abdelaziz Salem, Mohamed Mohamed Omar Jan 2003

Atomic Absorption And Spectrophotometeric Determinations Of Salicylhydroxamic Acid In Its Pure And Pharmaceutical Dosage Forms, Alaaeldin Abdelaziz Salem, Mohamed Mohamed Omar

Turkish Journal of Chemistry

A new method for the indirect determination of salicylhydroxamic acid (SHAM) using atomic absorption spectrometry (AAS) was proposed. The method is based on precipitating the ion associate complex of SHAM with [Cu (NH_{3})_{4}]^{2+}. The excess, unreacted, Cu^{2+} ions were determined using AAS. Another spectrophotometric method based on measuring the absorbance of the formed [Cu (NH_{3})_{4}]-SHAM complex in dioxane was proposed. The green color of the complex formed was measured at 330 nm. The two methods were successfully used for determining SHAM in its pure and pharmaceutical dosage forms. Using AAS, the drug was determined over a concentration range of 3.06 …

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Graft Copolymerization Of N-Vinylimidazole On Poly(Ethylene Terephthalate) Fibers In A Swelling Solvent Using Azobisisobutyronitrile As Initiator, Hali̇l İbrahi̇m Ünal, Can İnegöllü, Oya Şanli Jan 2003

Graft Copolymerization Of N-Vinylimidazole On Poly(Ethylene Terephthalate) Fibers In A Swelling Solvent Using Azobisisobutyronitrile As Initiator, Hali̇l İbrahi̇m Ünal, Can İnegöllü, Oya Şanli

Turkish Journal of Chemistry

In this study, poly(ethylene terephthalate) (PET) fibers were grafted in dimethylformamide (DMF) with n-vinylimidazole (n-VI) using azobisisobutyronitrile (AIBN) as an initiator. Variations of percentage grafting with time, temperature, monomer and initiator concentrations as well as monomer and initiator diffusions were investigated. It was observed that the percentage of grafting and grafting efficiency increased as time and temperature rose up to a certain value, and then they levelled off. The percentage of grafting was found to rise with increasing monomer and initiator concentrations, and then decrease. Monomer and initiator diffusions into PET fibers were shown to follow a similar trend and …

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Some Polyamidoxime Derivatives And Their Metal Complexes, Fatma Kari̇pci̇n, İbrahi̇m Karataş, Hali̇l İsmet Uçan Jan 2003

Some Polyamidoxime Derivatives And Their Metal Complexes, Fatma Kari̇pci̇n, İbrahi̇m Karataş, Hali̇l İsmet Uçan

Turkish Journal of Chemistry

In this paper the synthesis of six polyamidoximes from their corresponding diamines with 4,4'-methylenebis (phenylglyoxylohydroximoyl chloride) and 4,4'-methylenebis(chlorophenylgly-oxime) is presented. The average molecular weights of these organic polymers were determined. In addition, the complexes of 4,4'-methylenebis (phenylglyoxylohydroximoyl chloride) with Ni(II), Co(II) and Cu(II) salts were prepared. The structures of these compounds were identified by IR or ^{1}H NMR spectral data, elemental analyses, magnetic measurements and thermal analysis.

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Synthesis And Antimicrobial Testing Of Some Flavonylsulfonamide Derivatives, Gülgün Ayhan Kilcigi̇l, Oya Bozdağ Dündar, Rahmi̇ye Ertan, Nurten Altanlar Jan 2003

Synthesis And Antimicrobial Testing Of Some Flavonylsulfonamide Derivatives, Gülgün Ayhan Kilcigi̇l, Oya Bozdağ Dündar, Rahmi̇ye Ertan, Nurten Altanlar

Turkish Journal of Chemistry

Six new 4-amino-N-heteroaryl,N-[(2-phenyl-4H-1-benzopyran-4- oxo-6-yl)metil]benzensulfonamide derivatives, (3a-3f) were prepared by reacting 6-bromomethylflavone with the corresponding sulfonamide derivatives and their antimicrobial activities against Escherichia coli were evaluated. All of the compounds exhibited better activity (except compound 3c) than the corresponding sulfonamide derivatives.

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Synthesis, Characterization And Applications Of Sol-Gel Derived Zirconium Oxide Adsorbent Powder: Removal From Aqueous Solution Of Phenol And P-Chlorophenol, Murat Akarsu, Hi̇kmet Sayilkan, Şadi̇ye Şener, Funda Sayilkan, Ertuğrul Arpaç Jan 2003

Synthesis, Characterization And Applications Of Sol-Gel Derived Zirconium Oxide Adsorbent Powder: Removal From Aqueous Solution Of Phenol And P-Chlorophenol, Murat Akarsu, Hi̇kmet Sayilkan, Şadi̇ye Şener, Funda Sayilkan, Ertuğrul Arpaç

Turkish Journal of Chemistry

Adsorbent powders were prepared from the uncatalysed hydrolysis-condensation reactions of different complexes that were synthesized by the reactions of Zr(OPr^{n})_{4} with different chelating ligands (such as allylacetic acid [AAH], vinylacetic acid [VAH] and citraconic acid [CAH]). The complex products were characterized by FT-IR, ^{1}H-NMR and ^{13}C-NMR spectra. The maximum combination ratios of AAH/Zr(OPr^{n})_{4}, VAH/Zr(OPr^{n})_{4} and CAH/Zr(OPr^{n})_{4} were 1.7, 0.9 and 1.3, respectively. The hydrolysis-condensation products of these complexes were calcinated at 900 °C and half of them were coated with 3-glycidyloxypropyltrimethoxysilane (GLYMO). The surface area and average pore diameter of the powders were estimated by the analysis of adsorption/desorption BET …

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Micelle Formation In Sodium Dodecyl Sulfate And Dodecyltrimethylammonium Bromide At Different Temperatures, Yüksel Bayrak Jan 2003

Micelle Formation In Sodium Dodecyl Sulfate And Dodecyltrimethylammonium Bromide At Different Temperatures, Yüksel Bayrak

Turkish Journal of Chemistry

pH changes as a function of concentration for sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) were observed by the addition of 1 N HCl and 1 N KOH. pH values increased up to the critical micellar concentration (CMC) for the SDS/HCl system and decreased for the DTAB/KOH system. In the SDS/HCl and DTAB/KOH systems, the micellar phase had a fixed composition and was homogeneous and monodisperse above the CMC. However, in the SDS/KOH and DTAB/HCl systems, pH values increased in a continuous and gradual manner below and above the CMC, and the properties of the micellar phase changed with …

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Vibrational Spectroscopic Studies On Trans-1,4-Polychloroprene, V. Arjunan, S. Subramanian, S. Mohan Jan 2003

Vibrational Spectroscopic Studies On Trans-1,4-Polychloroprene, V. Arjunan, S. Subramanian, S. Mohan

Turkish Journal of Chemistry

Fourier transform infrared and Raman spectra of trans-1,4-polychloroprene have been recorded in the range of 4000-400 and 3500-100 cm^{-1}, respectively. In the present investigation, detailed assignments of the observed fundamental bands of trans-1,4-polychloroprene were analysed in terms of peak positions and relative intensities. In the hope of providing more effective information on the fundamental vibrations, a normal coordinate analysis was performed on trans-1,4-polychloroprene, by assuming C_{S} symmetry. The simple general valance force field (SGVFF) was employed in normal coordinate analysis and to calculate the potential energy distribution (PED) for each fundamental vibration. The PED contribution corresponding to each of the …

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Preparation And Characterization Of Conducting Polybutadiene/ Polythiophene Composites, Senem Kiralp, Zuhal Küçükyavuz, Atef F. Qasrawi Jan 2003

Preparation And Characterization Of Conducting Polybutadiene/ Polythiophene Composites, Senem Kiralp, Zuhal Küçükyavuz, Atef F. Qasrawi

Turkish Journal of Chemistry

Conductive composite films of cis-1,4-polybutadiene (PBD) with polythiophene (PTh) were prepared electrochemically. Thiophene was polymerized on PBD-coated platinium electrodes. The composites with different PTh percentages showed conductivity in the order of 10^{-3} (\Omega cm)^{-1}. The characterization of the films was performed using FTIR, scanning electron microscope and differential scanning calorimetry techniques. In order to understand the dominant transport mechanism, the temperature dependence of conductivity was investigated.

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Cover And Contents Jan 2003

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

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Isolation And Structure Elucidation Of Novel Natural Products From Turkish Lichens, Süheyla Kirmizigül, Ömer Koz, Hüseyi̇n Anil, Siddik İçli̇, Ulvi̇ Zeybek Jan 2003

Isolation And Structure Elucidation Of Novel Natural Products From Turkish Lichens, Süheyla Kirmizigül, Ömer Koz, Hüseyi̇n Anil, Siddik İçli̇, Ulvi̇ Zeybek

Turkish Journal of Chemistry

Three natural products were isolated from three different Turkish lichens. Microbiological investigations were also examined of these lichens. Compound 1 is known as 2-hydroxy-4-methoxy-3,6-dimethyl benzoic acid, and is isolated from Pseudevernia furfuracea for the first time. Compounds 2 and 3 are detected as new compounds and called, 3-acetyl-4-amino-2-chloro-1- (4-hydroxy-2-methoxy- 6-methylphenyl carbonyloxy) benzene and 2-(4-methoxyphenyl)-2-(5-oxo-4-phenyl-2,5- dihydro-2-furaniliden) acetic acid; they were isolated from Evernia prunastri and Letharia vulpina, respectively. All these compounds had different skeletons. Their structures were established by chemical methods and spectroscopic techniques using IR, UV, 1D and 2D NMR and EI and (+) FAB-Mass methods.

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Synthesis Of New 4-(5-Chloro-2-Oxo-3h-Benzoxazol-3-Yl)Butanamide Derivatives And Their Analgesic And Anti-Inflammatory Properties, H. Ozan Gülcan, Serdar Ünlü, Erden Banoğlu, M. Fethi̇ Şahi̇n, Esra Küpeli̇, Erdem Yeşi̇lada Jan 2003

Synthesis Of New 4-(5-Chloro-2-Oxo-3h-Benzoxazol-3-Yl)Butanamide Derivatives And Their Analgesic And Anti-Inflammatory Properties, H. Ozan Gülcan, Serdar Ünlü, Erden Banoğlu, M. Fethi̇ Şahi̇n, Esra Küpeli̇, Erdem Yeşi̇lada

Turkish Journal of Chemistry

In this preliminary screening study for developing potent analgesic and anti-inflammatory compounds, eight new 4-(5-chloro-2-oxo-3H-benzoxazol-3-yl)butanamide derivatives were synthesized and screened for their analgesic and anti-inflammatory activities as well as gastric ulceration potential in tested animals. Their structures were elucidated by their IR, ^{1}H-NMR and elemental analysis. All of the compounds exhibited high analgesic and anti-inflammatory activities. None of the compounds except compound 2g caused gastric lesions or bleeding in tested animals.

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A Novel, Semi-Pilot Scale Electrolysis System For The Production Of P-Aminophenol, Kamran Polat Jan 2003

A Novel, Semi-Pilot Scale Electrolysis System For The Production Of P-Aminophenol, Kamran Polat

Turkish Journal of Chemistry

Cyclic voltammetry (CV) and preparative electrolysis techniques were used to investigate the reduction of nitrobenzene into (NB) p-aminophenol (p-Ap). The electrodes used in CV experiments were glassy carbon (GC), TiO_{2}/Ti, Sn and Pb. The preparative electrolyses were carried out by the use of Pb, Sn, carbon cloth and TiO_{2}/Ti electrodes. The CV data were evaluated according to Nicholson-Shain criteria, and it was deduced that the reductions on TiO_{2}/Ti and GC electrodes were irreversible and monitored by an electrochemical-chemical-electrochemical mechanism. No reduction peak was observed with Sn and Pb electrodes. Preparative electrolyses were carried out under current-controlled conditions in the presence …

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Synthesis, Characterization And Primary Antituberculosis Activity Evaluation Of 4-(3-Coumarinyl)-3-Benzyl-4-Thiazolin-2-One Benzylidenehydrazones, Aysel Gürsoy, Ni̇lgün Karali̇ Jan 2003

Synthesis, Characterization And Primary Antituberculosis Activity Evaluation Of 4-(3-Coumarinyl)-3-Benzyl-4-Thiazolin-2-One Benzylidenehydrazones, Aysel Gürsoy, Ni̇lgün Karali̇

Turkish Journal of Chemistry

In this study a new series of 4-(3-coumarinyl)-3-benzyl-4-thiazolin- 2-one benzylidenehydrazones 3a-t was synthesized. Structures of the title compounds were elucidated by elemental analyses and spectrometric data (IR, ^1H-NMR, ^{13}C-NMR and EIMS). 3a-t were evaluated for antituberculosis activity against Mycobacterium tuberculosis} H37Rv in BACTEC 12B medium using the BACTEC 460 radiometric system.

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A Computational Investigation For The Chiral Chromatographic Separation Of Benzimidazole Type Sulphoxides, Hati̇ce Özdemi̇r Can Jan 2003

A Computational Investigation For The Chiral Chromatographic Separation Of Benzimidazole Type Sulphoxides, Hati̇ce Özdemi̇r Can

Turkish Journal of Chemistry

The computational study of chromatographic separations has become increasingly important in recent years. It supplies useful information about the mechanism of chromatographic separations and the design of stationary phases. In this study, the chromatographic separations of chiral benzimidazole type sulphoxides were analysed by utilising computational tools. The chiral separation mechanism of these compounds was analysed by molecular modelling methods. Molecular mechanics (MM+) were used as force field calculations. The separation factors and elution orders were determined from the interaction energies. Furthermore, the matrix effect on separation was investigated.

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Quantitative Analysis Of L-Hyoscyamine In Hyoscyamus Reticulatus L. By Gc-Ms, Murat Kartal, Semra Kurucu, Levent Altun, Ti̇murhan Ceyhan, Esi̇n Sayar, Şemsetti̇n Cevheroğlu, Yalcin Yetki̇n Jan 2003

Quantitative Analysis Of L-Hyoscyamine In Hyoscyamus Reticulatus L. By Gc-Ms, Murat Kartal, Semra Kurucu, Levent Altun, Ti̇murhan Ceyhan, Esi̇n Sayar, Şemsetti̇n Cevheroğlu, Yalcin Yetki̇n

Turkish Journal of Chemistry

The hyoscyamine content of leaves and root samples of Hyoscyamus reticulatus} L. from Bulanık, Muş in east Anatolia, Turkey, was determined by capillary GC-MS to be 0.036 \pm 0.004% in the leaves and 0.056 \pm 0.011\% in the roots as the predominant compound. Sopolamine was only detected in trace amounts. These findings are in accordance with reports on hyoscyamine content in Hyoscyamus} species. The limit of detection was 3.125 \mu g/mL and the limit of quantification was 6.25 \mu g/mL for hyoscyamine. This method has been shown to be linear and sensitive.

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Kinetics And Mechanism Of Oxidation Of L-Isoleucine And L-Ornithine Hydrochloride By Sodium N-Bromobenzenesulphonamide In Perchloric Acid Medium, Hemmige S. Yathirajan, Chapuradoddi R. Raju, Kikkeri N. Mohana, Sheena Shashikanth, Padmarajaiah Nagaraja Jan 2003

Kinetics And Mechanism Of Oxidation Of L-Isoleucine And L-Ornithine Hydrochloride By Sodium N-Bromobenzenesulphonamide In Perchloric Acid Medium, Hemmige S. Yathirajan, Chapuradoddi R. Raju, Kikkeri N. Mohana, Sheena Shashikanth, Padmarajaiah Nagaraja

Turkish Journal of Chemistry

Kinetic studies of the oxidation of L-isoleucine (ISL) and L-ornithine hydrochloride (ORH) by sodium N-bromobenzenesulphonamide (bromamine-B or BAB) were studied in aqueous perchloric acid medium. The rate shows first-order dependence on both [BAB]_0 and [amino acid]_0 and inverse first-order dependence on [H^+] for ISL and first-order dependence on [H^+] for ORH. The rate of reaction decreased with decreases in the dielectric constant of the medium. The addition of benzenesulphonamide (BSA), which is one of the reaction products, had no significant effect on the reaction rate. The rate remained unchanged with the variation in the ionic strength of the medium for …

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Effects Of Sucrose Concentration During Citric Acid Accumulation By Aspergillus Niger, Ayşegül Peksel, Cristian P. Kubicek Jan 2003

Effects Of Sucrose Concentration During Citric Acid Accumulation By Aspergillus Niger, Ayşegül Peksel, Cristian P. Kubicek

Turkish Journal of Chemistry

A number of regulatory mechanisms are involved in increasing citric acid production under certain conditions. The accumulation of citric acid takes place under the high concentration of carbon sources. The effect of sucrose as a carbon source on the accumulation of citric acid and tyrosine phosphorylated proteins during high glycolytic conditions was investigated using Aspergillus niger ATCC 11414. When mycelia are treated by different sucrose concentrations, a protein of \sim 27 kDa becomes tyrosine phosphorylated. This tyrosine phosphorylation takes place in response to signal transduction from the extracellular milieu. A possible role of this \sim 27 kDa protein in signal …

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Silver Removal From Aqueous Solution By Adsorption On Concrete Particles, Shakila Begum Jan 2003

Silver Removal From Aqueous Solution By Adsorption On Concrete Particles, Shakila Begum

Turkish Journal of Chemistry

The ability of concrete to remove silver from its aqueous solutions was studied. Silver removal is favored by low concentration and high pH at room temperature. The intrinsic acidity constants, average pK_{a1}^{int} and average pK_{a2}^{int} were determined. The calculated pH_{PZC} (5.4) is in agreement with the pH_{PZC} values determined from zeta potential measurements, indicating that the concrete particulate behaves amphoterically. The total acidity capacity for the negative and positive surface was 0.5 \muC/cm^2. A surface complex formation model (SCFM) was used to describe the adsorption of silver onto concrete particles. In general the equilibrium constants, the pK_S^i values, decrease as …

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Solid Phase Extraction Of Copper(Ii) By Modified Octadecyl Silica Membrane Disks With 3-{2-[2-(2-Hydroxyimino-1-Methyl-Propylideneamino)- Ethylamino]-Ethyl-Imino}-Butan-2-One~Oxime, Ömer Dalman, Serdar Karaböcek, Ahmet Demi̇rak, Mehmet Tüfekçi̇ Jan 2003

Solid Phase Extraction Of Copper(Ii) By Modified Octadecyl Silica Membrane Disks With 3-{2-[2-(2-Hydroxyimino-1-Methyl-Propylideneamino)- Ethylamino]-Ethyl-Imino}-Butan-2-One~Oxime, Ömer Dalman, Serdar Karaböcek, Ahmet Demi̇rak, Mehmet Tüfekçi̇

Turkish Journal of Chemistry

A simple, selective and rapid method for determining trace amounts of copper(II) ions in various types of water samples using atomic absorption spectrophotometry was investigated. Copper(II) ions from water samples were preconcentrated by solid phase extraction using octadecyl silica membrane disks modified with 3-{2-[2-(2-hydroxyimino- 1-methyl-propylideneamino)-ethylamino]-ethyl-imino}-butan-2-one oxime, (H_{2}mdo). The experimental conditions were optimized by changing several parameters such as volume of eluting solvent, the effect of pH, eluent flow rates, the amount of H_2mdo, breakthrough the volume, limit of detection and maximum capacity of the disks for Cu^{2+} recovery. The method was applied to the recovery of Cu(II) ions from seven …

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Catalytic Spectrophotometric Determination Of Manganese In Some Medicinal Plants And Their Infusions, Kostantin L. Mutaftchiev Jan 2003

Catalytic Spectrophotometric Determination Of Manganese In Some Medicinal Plants And Their Infusions, Kostantin L. Mutaftchiev

Turkish Journal of Chemistry

The catalytic effect of manganese (II) on the oxidation of the dye 1,3-Dimethyl- 2 [4-N (N,N-dimethylamino) phenylazo] imidazolium perchlorate (BR) with potassium periodate in the presence of 1,10-phenanthroline was investigated. The reaction was followed spectrophotometrically by measuring the decrease in the absorbance of the dye at 540 nm. Under optimum conditions (5 \times 10^{-5} mol dm^{-3} BR, 2 \times 10^{-4} mol dm^{-3} potassium periodate, 1 \times 10^{-4} mol dm^{-3} 1,10-phenanthroline, 0.1 mol dm^{-3} buffer -- pH 3.0, 70 °C, 5 min) manganese (II) in the range 0.1--4.5 ng cm^{-3} can be determined by the fixed-time method with a detection limit …

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Cerimetric Determination Of Propranolol In Bulk Drug Form And In Tablets, Kanakapura Basavaiah, Umakanthappa Chandrashekar, H. Chandrashekar Prameela Jan 2003

Cerimetric Determination Of Propranolol In Bulk Drug Form And In Tablets, Kanakapura Basavaiah, Umakanthappa Chandrashekar, H. Chandrashekar Prameela

Turkish Journal of Chemistry

Two simple, accurate and precise methods are described for the determination of propranolol hydrochloride with cerium(IV) sulphate. The titrimetric method is based on the oxidation of the drug by a known excess amount of cerium(IV) sulphate and back titration of the unconsumed oxidant with ammonium ferrous sulphate. In the spectrophotometric method, the unreacted cerium(IV) sulphate is treated with iron(II) sulphate, and the iron(III) sulphate produced is complexed with thiocyanate and measured at 480 nm, thereby permitting the determination of the amount of unreacted cerium(IV) sulphate. In both procedures, the amount of the reacted oxidant corresponds to the drug content. Different …

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The In Vitro Effects Of Dexamethasone On Sheep Lens Glucose-6-Phosphate Dehydrogenase, Şükrü Beydemi̇r, Destan Ni̇l Kulaçoğlu, Mehmet Çi̇ftçi̇, Ömer İrfan Küfrevi̇oğlu Jan 2003

The In Vitro Effects Of Dexamethasone On Sheep Lens Glucose-6-Phosphate Dehydrogenase, Şükrü Beydemi̇r, Destan Ni̇l Kulaçoğlu, Mehmet Çi̇ftçi̇, Ömer İrfan Küfrevi̇oğlu

Turkish Journal of Chemistry

Glucose-6-phosphate dehydrogenase (G6PD) enzyme was purified from sheep lenses, and the in vitro effects of dexamethasone on the enzyme's activity were investigated. Sheep lens glucose-6-phosphate dehydrogenase was purified 10,000-fold by using ammonium sulphate fractionation and 2',5'-ADP-Sepharose 4B affinity gel chromatography for a yield of 83.8\% and a specific activity of 7.6 EU/mg protein. Enzyme activity was determined by Beutler's method. Dexamethasone strongly inhibited the enzyme under in vitro conditions. The I_{50} value of the dexamethasone was 3.05 mM.

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Adsorption Of Arsenate And Chromate From Waters On Hydrophobized Zeolitic Media, Eva Chmielewska Jan 2003

Adsorption Of Arsenate And Chromate From Waters On Hydrophobized Zeolitic Media, Eva Chmielewska

Turkish Journal of Chemistry

A laboratory setup was used to examine the uptake of chromate and arsenate from aqueous solutions by octadecylammonium acetate [ODA]-modified inland clinoptilolite. In trials, a natural variety of montmorillonite was compared to organic, i.e. surfactant loaded clinoptilolite. and some inorganically substituted (Ag, Pb) monoforms. The arrangement of the surface-attached ODA chains was the important factor for differences in the adsorption states of the guest species (oxyanions). A novel nano-structure inorganic-organic composite was prepared and was characterized by SEM, thermogravimetry, HR TEM, UV-VIS diffuse reflectance and powder XRD spectral analytical methods. Finally, the adsorption isotherms of the studied system were expressed. …

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Potentiometric And Spectroscopic Studies With Chromium(Iii) Complexes Of Hydroxysalicylic Acid Derivatives In Aqueous Solution, M. Suat Aksoy, Ulvi̇ye Özer Jan 2003

Potentiometric And Spectroscopic Studies With Chromium(Iii) Complexes Of Hydroxysalicylic Acid Derivatives In Aqueous Solution, M. Suat Aksoy, Ulvi̇ye Özer

Turkish Journal of Chemistry

The stoichiometries and stability constants of the chromium(III) complexes of hydroxysalicylic acid ligands (2,x-dihydroxy benzoic acids; 2,x-DHBA, x = 4-6)(H_3L) were determined in aqueous solution by potentiometry and spectroscopy at 25 °C and at an ionic strength of 0.1 mol L^- (KNO_3). The existence of Cr(HL)^+ type complex was verified. The stability constants of coordination species that exist in Cr(III):2,x-DHBA systems were defined. In the acidic medium the major coordination species involve salicylate type coordination. The formation of monohydroxo complexes was observed at higher pH values.

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Investigation Of The Surface Acidity Of A Bentonite Modified By Acid Activation And Thermal Treatment, Tülay Alemdaroğlu, Gülcan Akkuş, Müşerref Onal, Yüksel Sarikaya Jan 2003

Investigation Of The Surface Acidity Of A Bentonite Modified By Acid Activation And Thermal Treatment, Tülay Alemdaroğlu, Gülcan Akkuş, Müşerref Onal, Yüksel Sarikaya

Turkish Journal of Chemistry

The adsorption of n-butylamine from its solution in cyclohexane on acid-activated and thermally treated Kütahya/Turkey bentonite (KB) samples was followed using a UV-VIS spectrophotometric method. The experimental data were evaluated by the Langmuir adsorption equation and the total number of surface acid centers (n_{m/mol} g^{-1}) was determined. The variation in n_m values as a function of the mass percent of H_2SO_4 used in activation (10%-70%) and its correlation with variations in surface area (A) and pore volume (V) as a function of the mass percent of H_2SO_4 were investigated for acid- activated KB samples. The variation in n_m values as …

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Isolation And Characterization Of A Smectite As A Micro-Mesoporous Material From A Bentonite, Müşerref Önal, Yüksel Sarikaya, Tülay Alemdaroğlu, İhsan Bozdoğan Jan 2003

Isolation And Characterization Of A Smectite As A Micro-Mesoporous Material From A Bentonite, Müşerref Önal, Yüksel Sarikaya, Tülay Alemdaroğlu, İhsan Bozdoğan

Turkish Journal of Chemistry

A procedure was assessed for obtaining an optimum amount of a micro-mesoporous material known as smectite from Reşadiye (Tokat/Turkey) bentonite. The procedure, which will permit a better economic evaluation of the Reşadiye reserves, is based on successive settlements of bentonite suspensions during various time intervals. To characterize the original bentonite, its fractions and the high purity smectite product, X-ray diffraction, differential thermal analysis, thermogravimetric analysis, scanning electron microscopy and nitrogen adsorption-desorption techniques were used. The original bentonite contained 50% by mass sodium-rich smectite (NaS) and 10% by mass NaCa-smectite (NaCaS). It also contained illite, clinoptilolite, analcime, feldspar, calcite, dolomite, quartz …

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Phenolic, Megastigmane, Nucleotide, Acetophenon And Monoterpene Glycosides From Phlomis Samia And P. Carica, Funda Nuray Yalçin, Tayfun Ersöz, Pinar Akbay, İhsan Çaliş, Ali̇ Arslan Dönmez, Otto Sticher Jan 2003

Phenolic, Megastigmane, Nucleotide, Acetophenon And Monoterpene Glycosides From Phlomis Samia And P. Carica, Funda Nuray Yalçin, Tayfun Ersöz, Pinar Akbay, İhsan Çaliş, Ali̇ Arslan Dönmez, Otto Sticher

Turkish Journal of Chemistry

Phytochemical investigations on the aerial parts of Phlomis samia resulted in the isolation of a simple phenolic glucoside, 2,6-dimethoxy-4-hydroxyphenol-1-O-\beta -D-glucopyranoside (1); a megastigmane glucoside, phlomuroside (=3-hydroxy-5,6-epoxy-\beta -ionol-9-O-\beta -D-glucopyranoside) (2); and a nucleotide glycoside, uridine (3). From the aerial parts of P. carica, the same phenolic glucoside, 2,6-dimethoxy-4-hydroxyphenol-1-O-\beta -D-glucopyranoside (1); as well as an acetophenon glucoside, picein (4); and 2 monoterpenoid glucosides, - betulalbuside A (5) and 1-hydroxylinaloyl-6-O-\beta -D-glucopyranoside (6) - were isolated and identified. The structure elucidation of the isolates was based on spectroscopic evidence.

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