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Articles 3421 - 3450 of 3876
Full-Text Articles in Physical Sciences and Mathematics
Organotin(Iv) Complexes Of Aniline Derivatives Part-Ii - Synthesis And Spectroscopic Characterization Of Organotin(Iv) Derivatives Of 2-[(4-Bromoanilino)Carboxyl]Benzoic Acid, Khadija Shahid, Saqib Ali, Saira Shahzadi, Zareen Akhtar
Organotin(Iv) Complexes Of Aniline Derivatives Part-Ii - Synthesis And Spectroscopic Characterization Of Organotin(Iv) Derivatives Of 2-[(4-Bromoanilino)Carboxyl]Benzoic Acid, Khadija Shahid, Saqib Ali, Saira Shahzadi, Zareen Akhtar
Turkish Journal of Chemistry
A series of organotin(IV) complexes with the general formula R_{2}SnL_{2} and R_{3}SnL, where R = CH_{3}, C_{2}H_{5}, n-C_{4}H_{9}, C_{6}H_{5}, C_{6}H_{5}CH_{2} and L = 2-[(4-bromoanilino)carboxyl]benzoate, were synthesized and characterized by infrared, mass and multinuclear NMR (^{1}H, ^{13}C, ^{119}Sn) spectroscopies. The coordination around tin in solid as well as in solution has been proposed on the basis of spectroscopic results.
Characterization Of Polyphenol Oxidase From Jerusalem Artichoke (Helianthus Tuberosus), Emi̇ne Zi̇yan, Şule Pekyardimci
Characterization Of Polyphenol Oxidase From Jerusalem Artichoke (Helianthus Tuberosus), Emi̇ne Zi̇yan, Şule Pekyardimci
Turkish Journal of Chemistry
Polyphenol oxidases (PPO) in Jerusalem arthichoke (Helianthus tuberosus) skin and flesh were extracted and purified through (NH_{4})_{2}SO_{4} precipitation, dialysis and gel filtration chromatography. The samples obtained from ammonium sulfate precipitation and dialysis were used for the characterization of crude skin and flesh PPO. Optimum pH values were 7.5 for skin PPO and 8.0 for flesh PPO with 50 mM catechol. The optimum temperatures for skin and flesh PPO were 25 °C and 30 °C respectively with catechol. Six inhibitors were tested in the study and the most effective inhibitors were found to be sodium azide and thiourea for both flesh …
Flow Injection Speciation Analysis Of Manganese In Real Samples By Diphenylcarbazide-Spectrophotometric Determination, Kazem Kargosha, Meissam Noroozifar
Flow Injection Speciation Analysis Of Manganese In Real Samples By Diphenylcarbazide-Spectrophotometric Determination, Kazem Kargosha, Meissam Noroozifar
Turkish Journal of Chemistry
The flow injection speciation of manganese in aqueous solution using a spectrophotometry method of detection is presented. Manganese (VII) can be determined spectrophotometrically at 308 nm after the reaction with Sym-diphenycarbazide in buffered at pH = 3.05 with phosphate. Under the optimized conditions, total manganese concentration can also be determined after oxidation of Mn^{2+} to MnO_{4}^{-} and then Mn^{2+} concentration can be calculated from the difference. The linear range of determination is 0.047-4.50 mg/l with a 3\sigma detection limit of 31 \mu g/l. The proposed method is applied to the determination of MnO_{4}^{-} and Mn^{2+} in effluent streams and foods …
Column Preconcentration/Separation And Atomic Absorption Spectrometric Determinations Of Some Heavy Metals In Table Salt Samples Using Amberlite Xad-1180, Mustafa Soylak, Aslihan Uzun Karatepe, Lati̇f Elçi̇, Mehmet Doğan
Column Preconcentration/Separation And Atomic Absorption Spectrometric Determinations Of Some Heavy Metals In Table Salt Samples Using Amberlite Xad-1180, Mustafa Soylak, Aslihan Uzun Karatepe, Lati̇f Elçi̇, Mehmet Doğan
Turkish Journal of Chemistry
A simple and sensitive solid phase extraction procedure on Amberlite XAD-1180 resin is presented for the determination of chromium, cobalt, manganese and nickel at trace levels by atomic absorption spectrometry. The analyte ions were quantitatively taken at pH 9 by using ammonia/ammonium acetate buffer without any chelating agent. The influences of some analytical parameters such as sample volume, eluent type and flow rates on the retention of Cr, Co, Mn and Ni ions were examined. No influences were observed from the matrix ions of table salt samples. The detection limits for Cr, Co, Mn and Ni were 0.27 \mu g/g, …
Gas Chromatographic Separation Of Phenol Derivatives By Schiff-Base Liquid Crystalline Stationary Phases, M. A. Ali, A. M. Al-Haideri, M. T. S. Al-Mehdawy
Gas Chromatographic Separation Of Phenol Derivatives By Schiff-Base Liquid Crystalline Stationary Phases, M. A. Ali, A. M. Al-Haideri, M. T. S. Al-Mehdawy
Turkish Journal of Chemistry
The chromatographic behaviour of liquid crystalline compounds benzylidene-p-aminobenzoic acid and 4-(p-methyl benzylidene)-p-aminobenzoic acid as stationary phases for the separation of dimethylphenol isomers was investigated. These isomers were analysed on benzylidene-p-aminobenzoic acid within a nematic range of 169-194 °C with a temperature interval of 5 °C. Better peak resolution was at a column temperature of 190 °C. The analysis was repeated on a 4-(p-methyl benzylidene)-p-aminobenzoic acid column at a nematic temperature of 256 °C, which represented the end of the nematic range, and gave the optimum peak resolution. It was found that isomer better separation was obtained at 20% loading for …
Kinetics And Mechanism Of Oxidation Of Some Hydroxy Butyric Acid Salts By Ditelluratocuprate(Iii) In Alkaline Medium, Jin-Huan Shan, Li-Ping Wang, Shi-Gang Shen, Han-Wen Sun
Kinetics And Mechanism Of Oxidation Of Some Hydroxy Butyric Acid Salts By Ditelluratocuprate(Iii) In Alkaline Medium, Jin-Huan Shan, Li-Ping Wang, Shi-Gang Shen, Han-Wen Sun
Turkish Journal of Chemistry
The kinetics of oxidation of 2-hydroxy butyric acid salt (2-HBAS) and 3-hydroxy butyric acid salt (3-HBAS) by ditelluratocuprate(III) (DTC) were studied spectrophotometrically between 298.2 K and 313.2 K in alkaline medium. The reaction rate showed first order dependence in DTC and a fractional order in HBAS. It was found that the pseudo-first order rate constant k_{obs} increased with an increase in the concentration of OH^- and a decrease in the concentration of TeO_{4}^{2-}. The reaction rate changed with the position of the hydroxyl group. There was a negative salt effect. A plausible mechanism involving a pre-equilibrium of adduct formation between …
Bisabolane Type Sesquiterpenes From A Marine Didiscus Sponge, Deni̇z Taşdemi̇r, Timothy S. Bugni, Gina C. Mangalindan, Gisela P. Concepcion, Mary Kay Harper, Chris M. Ireland
Bisabolane Type Sesquiterpenes From A Marine Didiscus Sponge, Deni̇z Taşdemi̇r, Timothy S. Bugni, Gina C. Mangalindan, Gisela P. Concepcion, Mary Kay Harper, Chris M. Ireland
Turkish Journal of Chemistry
Two bisabolane type sesquiterpene phenols, (+)-curcuphenol (1) and (+)-curcudiol (2), were isolated from a Philippine marine sponge, Didiscus sp., in addition to \beta -sitosterol (3) and phenethylamine (4). The structures of the metabolites were established on the basis of spectral evidence (1D- and 2D NMR, [\alpha]_{D}, EIMS). (+)-Curcuphenol (1) showed cytotoxicity, which is indicative of a p53 independent mechanism.
Bromination Of 1-Cyclopent-1-En-1-Ylbenzene And 1-(5-Bromocyclopent-1-En-1-Yl)Benzene And Theoretical Investigation Of The Products, Mustafa Ceylan, Armağan Kinal, Yaşar Sütbeyaz, Meti̇n Balci
Bromination Of 1-Cyclopent-1-En-1-Ylbenzene And 1-(5-Bromocyclopent-1-En-1-Yl)Benzene And Theoretical Investigation Of The Products, Mustafa Ceylan, Armağan Kinal, Yaşar Sütbeyaz, Meti̇n Balci
Turkish Journal of Chemistry
The bromination of 1-cyclopent-1-en-1-ylbenzene (4) in different solvents and at different temperatures was accompanied by the evolution of hydrogen bromide and yielded 1-(5-bromocyclopent-1-en-1-yl)benzene (8). Further bromination of 8 gave exclusively 2R(S),5R(S)-1-(1,2,5-tribromocyclopentyl)benzene (11). The experimental results were compared with the theoretical ones based on semi-empirical (MM+ and AM1), Hartree-Fock (HF) and density functional theory (DFT). The formation of 11 was explained by the formation of a weakly bridged bromoniun ion of type 9.
Determination Of Manganese, Copper, Cadmium And Lead By Faas After Solid-Phase Extraction Of Their Phenylpiperazine Dithiocarbamate Complexes On Activated Carbon, Hasan Cesur
Turkish Journal of Chemistry
A solid-phase extraction method was developed for the pre-concentration of manganese, copper, cadmium and lead in water samples prior to their determination by flame atomic absorption spectrometry using phenylpiperazine dithiocarbamate as a new reagent. The optimum pre-concentration conditions have been investigated such as pH, volume of sample solution and the effects of some matrix elements. The obtained recovery was nearly 90 to 100, while the enrichment factor was 400 for metal spiked solutions.
Spectrophotometric Determination Of Iron(Ii) With 5-Nitro-6-Amino-1,10-Phenanthroline, Nebahat Demi̇rhan, Fi̇kri̇ye Tuncel Elmali
Spectrophotometric Determination Of Iron(Ii) With 5-Nitro-6-Amino-1,10-Phenanthroline, Nebahat Demi̇rhan, Fi̇kri̇ye Tuncel Elmali
Turkish Journal of Chemistry
A new spectrophotometric method is developed for the determination of Fe(II) with 5-nitro-6-amino-1,10-phenanthroline (NAF). In this work, the effect of factors such as pH, amount of reagent (NAF), reaction time and temperature were investigated. The method is based on the formation of a colored product between Fe(II) and NAF. The reaction proceed quantitatively at 20 °C for 210 min in acidic medium. The absorption maximum was at 520 nm. A linear relationship existed between absorbance and Fe(II) concentration over the range 0.1 \mu g/mL and 0.4 \mu g/mL. The molar ratio of Fe(II) to the reagent was determined as 1:3. …
Production Of An E. Coli Toxin Protein; Colicin A In E. Coli Using An Inducible System, İsa Gökçe, Jeremy H. Lakey
Production Of An E. Coli Toxin Protein; Colicin A In E. Coli Using An Inducible System, İsa Gökçe, Jeremy H. Lakey
Turkish Journal of Chemistry
Colicins are bacterial toxins that kill Escherichia coli and related cells; their mode of action is of interest in protein import and toxicology. Colicins translocate across the E. coli outer membrane and periplasm by interacting with several receptors. This translocation process involves interaction of the colicin with the outer membrane porin OmpF and subsequently with the integral membrane protein TolA. The N-terminal domain of colicin N is involved in the import process. Our aim was to produce a large quantity of colicin A for functional and structural studies. It is a prerequisite to have a correctly folded and stable protein …
Simultaneous Determination Of Copper, Zinc And Selenium In Chicken Liver By Differential Pulse Polarography, Güler Ekmekci̇, Güler Somer, Olcay Şendi̇l
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 …
Effect Of Polyoxyethylene Chain Length And Electrolyte On The Viscosity Of Mixed Micelles, Hali̇de Akbaş, Tali̇ha Si̇di̇m, Mehmet İşcan
Effect Of Polyoxyethylene Chain Length And Electrolyte On The Viscosity Of Mixed Micelles, Hali̇de Akbaş, Tali̇ha Si̇di̇m, Mehmet İşcan
Turkish Journal of Chemistry
The viscosity measurements of micelles composed of mixtures of anionic/nonionic surfactants were carried out as a function of the mole fraction of surfactants. The systems studied were sodium dodecyl sulfate (SDS)-polyoxyethylene lauryl ether (C_{12}POE_{n} n = 4, 10 and 23) in water and 0.1 M sodium chloride solution. In the single systems, the relative viscosity of nonionic surfactant is greater than that of SDS, and increases with the increasing level of ethylene oxide. In the mixed surfactant systems, the relative viscosities vary at the mixed molar fraction of SDS, between 0.2 and 0.3, and then the relative viscosities of mixed …
Production Of Bacterial Polyesters From Some Various New Substrates By Alcaligenes Eutrophus And Pseudomonas Oleovorans, Hali̇l Koçer, Mehli̇ka Borcakli, Songün Demi̇rel, Baki̇ Hazer
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 …
Atomic Absorption And Spectrophotometeric Determinations Of Salicylhydroxamic Acid In Its Pure And Pharmaceutical Dosage Forms, Alaaeldin Abdelaziz Salem, Mohamed Mohamed Omar
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 …
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
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 …
Vibrational Spectroscopic Studies On Trans-1,4-Polychloroprene, V. Arjunan, S. Subramanian, S. Mohan
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 …
The Effect Of Tert-Butylhydroperoxide On The Thiol Redox Status In Human Erythrocytes And The Protective Role Of Glucose And Antioxidants, Yasemi̇n Aksoy, İ. Hamdi̇ Öğüş, Nazmi̇ Özer
The Effect Of Tert-Butylhydroperoxide On The Thiol Redox Status In Human Erythrocytes And The Protective Role Of Glucose And Antioxidants, Yasemi̇n Aksoy, İ. Hamdi̇ Öğüş, Nazmi̇ Özer
Turkish Journal of Chemistry
For survival, living cells maintain their thiol redox status within acceptable limits by three different mechanisms: i. glutathione disulfide export, ii. reduction of glutathione disulfide by pentose phosphate pathway and, iii. reduction of glutathione disulfide by Protein-SH. To assess the relative contribution of each one of the systems, intracellular [glutathione], [glutathione disulfide] and their export, in fresh and aged erythrocytes subjected to oxidative stress, in \pm glucose and \pm antioxidants, were measured. Glutathione was rapidly oxidized by tert-butylhydroperoxide in \pm glucose in both groups. The regeneration of glutathione, in both groups, in \pm glucose was about 100 and 50%, respectively. …
Synthesis Of New Antimicrobial Agents; Amide Derivatives Of Pyranones And Pyridinones, Mutlu Di̇lsi̇z Aytemi̇r, Robert C. Hider, Di̇lek Demi̇r Erol, Meral Özalp, Meli̇ke Eki̇zoğlu
Synthesis Of New Antimicrobial Agents; Amide Derivatives Of Pyranones And Pyridinones, Mutlu Di̇lsi̇z Aytemi̇r, Robert C. Hider, Di̇lek Demi̇r Erol, Meral Özalp, Meli̇ke Eki̇zoğlu
Turkish Journal of Chemistry
In this study, 4(1H)-pyridinones with an amide function in Position 2 of the pyridinone ring showed antimicrobial activity. The synthesis and the biological properties of some novel amide derivatives of pyran-4(1H)-one and 4(1H)-pyridinone have been reported. Amide derivatives of pyran-4(1H)-one and 4(1H)-pyridinone were prepared using two different methods. Antimicrobial activities were determined as MIC values using the microdilution broth method against the bacteria Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa and the fungi Candida albicans, Candida krusei and Candida parapsilosis. Compounds 6 and 9 exhibited the best inhibitor activity against S. aureus.
Synthesis And Antimicrobial Testing Of Some Flavonylsulfonamide Derivatives, Gülgün Ayhan Kilcigi̇l, Oya Bozdağ Dündar, Rahmi̇ye Ertan, Nurten Altanlar
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.
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
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 …
Micelle Formation In Sodium Dodecyl Sulfate And Dodecyltrimethylammonium Bromide At Different Temperatures, Yüksel Bayrak
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 …
A Novel, Semi-Pilot Scale Electrolysis System For The Production Of P-Aminophenol, Kamran Polat
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 …
Voltammetric And Flow Injection Amperometric Determination Of Cysteine At A Glassy Carbon Electrode In The Presence Of Copper(Ii) Ions, Zekerya Dursun, İlyas Şahbaz, F. Ni̇l Ertaş, Gürel Ni̇şli̇
Voltammetric And Flow Injection Amperometric Determination Of Cysteine At A Glassy Carbon Electrode In The Presence Of Copper(Ii) Ions, Zekerya Dursun, İlyas Şahbaz, F. Ni̇l Ertaş, Gürel Ni̇şli̇
Turkish Journal of Chemistry
The voltammetric behaviour of cysteine was investigated in the presence of Cu(II) ions at a rotating glassy carbon electrode (RGCE). Two reduction peaks related to the successive reduction of the cysteine complexes of Cu(II) and Cu(I) ions were observed at --0.30 and --0.60 V vs. SCE respectively. These peaks were increased upon the addition of cysteine into a pH 9.20 borate buffer solution containing 0.1 M KNO_{3} and 1.0 x 10^{-5} M Cu(II) ions. The calibration curve was linear in the concentration range of 5.0 x 10^{-10}- 2.0 x 10^{-8} M for cysteine by utilising the peak current at --0.6 …
Thermogravimetric Characterization Of Turkish Bituminous Coals For Combustion, Sai̇t Kizgut, Di̇lek Cuhadaroğlu, İhsan Toroğlu
Thermogravimetric Characterization Of Turkish Bituminous Coals For Combustion, Sai̇t Kizgut, Di̇lek Cuhadaroğlu, İhsan Toroğlu
Turkish Journal of Chemistry
This study focused on the thermal gravimetric characterization of Turkish bituminous coals for combustion. The combustion properties considered were based on the burning profile of coal samples and their chars produced in a PL 1500 TGA apparatus. The coal seam samples used in the study were obtained from TTK (Turkish Hardcoal Enterprise) mines as channel samples. The majority of the samples from 12 seams were medium-volatile bituminous and only three of them were high-volatile bituminous. Combustion profile parameters of coal samples and chars were correlated with petrographic, proximate and ultimate analysis data in order to establish the combustion differences of …
Differential Pulse Polarographic Determination Of Cadmium After Solid Liquid Extraction And Preconcentration Using Pan, Mohammad Ali Taher
Differential Pulse Polarographic Determination Of Cadmium After Solid Liquid Extraction And Preconcentration Using Pan, Mohammad Ali Taher
Turkish Journal of Chemistry
A highly selective, sensitive, rapid and economical differential pulse polarographic method has been developed for the determination of trace amounts of cadmium in various samples after the adsorption of its 1-(2-pyridylazo)-2-naphthol (PAN) complex on microcrystalline naphthalene in the pH range of 8.2-11.0. After filtration, the solid mass is shaken with 9.0 mL of 1 M hydrochloric acid and cadmium is determined by differential pulse polarography. Cadmium can alternatively be quantitatively adsorbed on [1-(2-pyridylazo)-2-naphthol]-naphthalene adsorbent packed in a column and determined similarly. The detection limit is 0.07 \mu g/mL (signal-to noise ratio = 2) and the linearity is maintained in the …
Dna Cleavage Activity Of Diazonium Salts: Chemical Nucleases, Murat Kizil, Ebru İnce Yilmaz, Necmetti̇n Pi̇ri̇nççi̇oğlu, Çeti̇n Ayteki̇n
Dna Cleavage Activity Of Diazonium Salts: Chemical Nucleases, Murat Kizil, Ebru İnce Yilmaz, Necmetti̇n Pi̇ri̇nççi̇oğlu, Çeti̇n Ayteki̇n
Turkish Journal of Chemistry
4-Fenoldiazonium tetrafluoroborate and 4-benzoicaciddiazonium tetrafluoroborate was prepared and was shown to be an effective DNA cleavage agent in the presence of the 1-electron donor copper(II) chloride. Its mechanism involves the generation of the aryl radical cleaving DNA by hydrogen atom abstraction from deoxyribose sugar.
Synthesis, Characterization And Primary Antituberculosis Activity Evaluation Of 4-(3-Coumarinyl)-3-Benzyl-4-Thiazolin-2-One Benzylidenehydrazones, Aysel Gürsoy, Ni̇lgün Karali̇
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.
A Computational Investigation For The Chiral Chromatographic Separation Of Benzimidazole Type Sulphoxides, Hati̇ce Özdemi̇r Can
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.
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
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.