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Articles 9481 - 9510 of 10317
Full-Text Articles in Physical Sciences and Mathematics
Studies On The Methylation Of 5-Nitro-Benzimidazoles, Mashooda Hasan, Farzana Shaheen, Uzma Yunus
Studies On The Methylation Of 5-Nitro-Benzimidazoles, Mashooda Hasan, Farzana Shaheen, Uzma Yunus
Turkish Journal of Chemistry
Methylation of 2H, 5-nitro- (1) and 2-ethyl, 5-nitro- (2) benzimidazoles separately with methyl iodide in acetone in the presence of potassium carbonate yielded 2H, 5/6-nitro-(3A and 3B) and 2-ethyl, 5/6-nitro- (4A and 4B) methylbenzimidazoles respectively. Methylation of 1 and 2 in dimethylformamide in place of acetone yielded not only 3A, 3B and 4A, 4B respectively, but in addition 1,3-dimethyl-5-nitro-benzimidazol-2-one (5) was also obtained in each case. The structure of the synthesized compounds was determined with the help of mass and ^1H NMR spectroscopic analysis.
Synthesis Of 4-Benzyl-1-Piperazineglyoxime And Its Use In The Spectrophotometric Determination Of Nickel, Mustafa Maci̇t, Hümeyra Bati, Beki̇r Bati
Synthesis Of 4-Benzyl-1-Piperazineglyoxime And Its Use In The Spectrophotometric Determination Of Nickel, Mustafa Maci̇t, Hümeyra Bati, Beki̇r Bati
Turkish Journal of Chemistry
A new reagent, 4-benzyl-1-piperazineglyoxime(BPGH_2), was synthesized and used for developing a simple and rapid extractive method for the spectrophotometric determination of nickel. This method is based on the selective extraction of nickel complex from aqueous solution into carbontetrachloride and the measurement of the absorption at 267 nm. The method was applied to the determination of nickel ion in some standard and practical samples.
Determination Of Thermodynamic Parameters Of Some Complexes Of 9-Ethyl-3-Carbazolecarboxaldehyde 4-Phenyl-3-Thiosemicarbazone (Eccapt), E. Güler Akgemci̇, Tevfi̇k Atalay
Determination Of Thermodynamic Parameters Of Some Complexes Of 9-Ethyl-3-Carbazolecarboxaldehyde 4-Phenyl-3-Thiosemicarbazone (Eccapt), E. Güler Akgemci̇, Tevfi̇k Atalay
Turkish Journal of Chemistry
The complexes of Cu(II), Co(II), Zn(II), and Cd(II) with 9-ethyl-3-carbazolecarboxaldehyde 4-phenyl-3-thiosemicarbazone were synthesized and their stability constants were determined using a spectrophotometric method at different temperatures (25, 30, 35 and 40 \pm 0.1°C) and ionic strengths (0.05, 0.01 and 0.20 M KNO_3) in 50% (v/v) aqueous DMF. From these constants, the thermodynamic stability constants and thermodynamic parameters (\Delta G°, \Delta H° and \Delta S°) were calculated.
The Synthesis Of Manganese(Iii) Acetate In Bipolar Packed-Bed And Trickle-Bed Electrode Cells, Altan Güvenç, Belgi̇n Karabacakoğlu, Ö. Mete Koçkar, A. Tarik Pekel
The Synthesis Of Manganese(Iii) Acetate In Bipolar Packed-Bed And Trickle-Bed Electrode Cells, Altan Güvenç, Belgi̇n Karabacakoğlu, Ö. Mete Koçkar, A. Tarik Pekel
Turkish Journal of Chemistry
In this research, the electrochemical oxidation of Mn(II) acetate to Mn(III) acetate was investigated in aqueous acetic acid solution, using a bipolar particulate electrode cell. In order to determine the effect of flow modes on the yield of Mn(III) acetate, which is an important oxidizing agent and catalyst in organic reactions, a bipolar particulate electrode cell was employed both in flooded and trickle flow modes. The experiments were conducted at controlled potentials of 50-250 volts using the solution (10% H_2O, 90% CH_3COOH, 0.1 M Mn(CH_3COO)_2.4H_2O, 0.1 M CH_3COONa.3H_2O) and at an optimum flow rate of 0.04 ml.s^{-1}. The values of …
Some Properties Of Cu, Zn-Superoxide Dismutase From Sheep Erythrocyte, Leman Tarhan, M. Nalan Tüzmen
Some Properties Of Cu, Zn-Superoxide Dismutase From Sheep Erythrocyte, Leman Tarhan, M. Nalan Tüzmen
Turkish Journal of Chemistry
Superoxide dismutase (SOD) was isolated from sheep erythrocyte. SOD activity was measured under the optimized assay conditions by observing the variations of autoxidation rate of 6-hydroxydopamine (6-OHDA). The enzyme was characterized as containing copper and zinc and was insensitive to chloroform-ethanol mixture but inhibited by cyanide and hydrogen peroxide. The activity variations and stability properties of sheep erythrocyte Cu, Zn-SOD were investigated under the optimized activity assay conditions by observing inhibition change at the autoxidation rate of 6-OHDA. The optimum pH and temperature of sheep erythrocyte Cu, Zn-SOD were found to be 9.4 and 30$^{\circ}$C respectively. The enzyme showed high …
Magnitudes Of Back Diffusion During Long-Term Diffusive Sampling Of Volatile Organic Compounds Using Carbotrap And Chromosorb 106, Naci̇ye Kiliç, James A. Ballantine
Magnitudes Of Back Diffusion During Long-Term Diffusive Sampling Of Volatile Organic Compounds Using Carbotrap And Chromosorb 106, Naci̇ye Kiliç, James A. Ballantine
Turkish Journal of Chemistry
The aim of the research was to investigate the magnitudes of the losses of some volatile organic compounds from the solid adsorbents, Carbotrap and Chromosorb 106 due to back diffusion during long-term diffusive sampling of volatile organic compounds in the environment. Experiments were performed by loading the compounds to be tested on the adsorbent tubes and leaving them in an outdoor environment to simulate the real life sampling conditions over a 14 day period. The losses due to back diffusion were investigated for both the high and the low initial concentrations of the fourteen compounds covering a wide range of …
Swelling Behavior Of Acrylamide-2-Hydroxyethyl Methacrylate Hydrogels, Belma Işik Yürüksoy
Swelling Behavior Of Acrylamide-2-Hydroxyethyl Methacrylate Hydrogels, Belma Işik Yürüksoy
Turkish Journal of Chemistry
In this study, hydrogels of poly(acrylamide-co-2-hydroxyethyl methacrylate) having different properties were prepared by a redox polymerization method. Poly(ethylene glycol), PEG 4000 was included in the polymerization recipe to increase the microporosity of the resultant polymeric structures. AAm/HEMA hydrogels with different properties were obtained by changing initial AAm/HEMA mole ratio, total monomer, PEG 4000 and crosslinker concentrations.
Solvent Extraction Of Fe^{3+} Cation By Diazo-Coupling Calix[4]Arenes, Hasaletti̇n Deli̇göz, Emi̇n Erdem, Hasan Kocaokutgen
Solvent Extraction Of Fe^{3+} Cation By Diazo-Coupling Calix[4]Arenes, Hasaletti̇n Deli̇göz, Emi̇n Erdem, Hasan Kocaokutgen
Turkish Journal of Chemistry
The solvent extraction of Fe^{3+} cations from the aqueous to the organic (chloroform) phase was carried out using p-tert-butyl calix[4]arene(\underline{1}), calix[4]arene(\underline{2}), diazo-coupling calix[4]arenes [p-(4-n-butyl-phenylazo)calix[4]arene (\underline{3}), p-(4-phenylazophenylazo)calix[4]arene(\underline{4}), p-(4-acetanilidazo)calix[4]arene(\underline{5}), p-(N'-2-thyazol-2ylsulphanylazo)calix[4]arene(\underline{6}) and p-(2-thyazolazo)calix[4]arene(\underline{8}) and the derivatives of phenol [2-(5-bromo-2-pyridylazo)-5-diethylaminophenol(\underline{8}) (Bromo-PADAP) and 2-hydroxy-5-methyl\-phenylazonapthol(\underline{9}) (HMPAN)]. It was found that the compounds (\underline{1}-\underline{9}) showed the highest extractability toward Fe^{3+} at pH 4.5-5.4 Compound \underline{5} shows strong binding ability to Fe^{3+} ion. Based on the method of continuous variation, calixarene \underline{5} formed a 1:1 complex with Fe^{3+} ion.
X-Ray Diffraction Study Of Heat-Treated Graphitized And Ungraphitized Carbon, Rizwan Hussain, Riaz Qadeer, Mahmood Ahmad, M. Saleem
X-Ray Diffraction Study Of Heat-Treated Graphitized And Ungraphitized Carbon, Rizwan Hussain, Riaz Qadeer, Mahmood Ahmad, M. Saleem
Turkish Journal of Chemistry
Heat treatment of graphitized and ungraphitized carbon samples was carried out in air and argon atmosphere from ambient temperature to 700$^{\circ}$C. The changes in degree of amorphousness, mean crystallite size and interlayer separations were studied employing x-ray diffraction. The results revealed an increase in crystallinity when graphitized carbon was heated to 100 ^oC and above. This enhanced degree of arrangement is indicative of the removal of residual impurities entrapped during the production processes. In ungraphitized carbon, the transition from amorphous to crystalline character was not observed upon heat treatment.
Stereoselective Synthesis Of Butenolide And Butyrolactone Derivatives, Abdulkadi̇r Sirit
Stereoselective Synthesis Of Butenolide And Butyrolactone Derivatives, Abdulkadi̇r Sirit
Turkish Journal of Chemistry
Optically active butenolide and $\gamma$-butyrolactone derivatives were prepared by removing (R)-phenyl glycinol and (1R, 2R)-norpseudoephedrine used as chiral auxiliaries from butenolides and \gamma-butyrolactones in two steps. The structures of these products were determined using ^1H NMR, ^{13}C NMR, Mass spect., IR and microanalysis.
High Fluorescence Emissions Of Some Natural Benzofurane Derivatives Isolated From Styrax Officinalis, Siddik İçli̇, Hüseyi̇n Anil, Bi̇rcan Di̇ndar, Özgen Alankuş Çalişkan, Yurdanur Yayla, Andrey O. Doroshenko, Serap Alp
High Fluorescence Emissions Of Some Natural Benzofurane Derivatives Isolated From Styrax Officinalis, Siddik İçli̇, Hüseyi̇n Anil, Bi̇rcan Di̇ndar, Özgen Alankuş Çalişkan, Yurdanur Yayla, Andrey O. Doroshenko, Serap Alp
Turkish Journal of Chemistry
The fluorescent properties of several natural benzofuran derivatives, egonols, isolated from {\it Styrax officinalis}, were determined. The studied egonol derivatives were found to be effective UV organic luminophores, with quantum yields of near to unity, \( \varphi_{f} \) = 0.92. The fluorescence quenching experiments with electron donor molecules of aniline, N,N-dimethylaniline and carbazolocarbazole, presented very high efficiency of quenching at above diffusion quenching rates of 4.5$\times$10\( ^{10} \), 2.1$\times$10\( ^\times \) and 5.6$\times$10\( ^{12} \) s\( ^{-1} \)mol\( ^{-1} \), respectively. A strong electron acceptor molecule, tetranitrofluorenone, presented quenching rate of 2.6$\times$10\( ^{11} \) s\( ^{-1} \)mol\( ^{-1} \). It …
Heavy Metal Removal From Aquatic Systems By Northern Anatolian Smectites, Çi̇ğdem Arpa, Ridvan Say, Nuray Şatiroğlu, Sema Bektaş, Yuda Yürüm, Ömer Genç
Heavy Metal Removal From Aquatic Systems By Northern Anatolian Smectites, Çi̇ğdem Arpa, Ridvan Say, Nuray Şatiroğlu, Sema Bektaş, Yuda Yürüm, Ömer Genç
Turkish Journal of Chemistry
Competitive adsorption of the heavy metal ions Cu(II), Cd(II) and Pb(II) from aqueous media onto northern Anatolian smectites with a mean particle diameter of 200 $\mu$m, was investigated. The adsorption rate and capacity of the smectite for the selected heavy metal ions, containing different amounts of these ions (5-900 mg/L) at values ranging from pH 1.0 to 7.0 were studied. Very high adsorptions rates were observed at the beginning, and adsorption equilibria were then gradually achieved in about 30 minutes. The maximum adsorption of metal ions onto the smectite were found to be 41.46 mg Cd(II), 36.11 mg Pb(II) and …
The Effect Of Peripheral Circuits On The Total \Pi-Electron Energies Of Cyclacenes, Lemi̇ Türker
The Effect Of Peripheral Circuits On The Total \Pi-Electron Energies Of Cyclacenes, Lemi̇ Türker
Turkish Journal of Chemistry
Within the framework of the Hückel molecular orbital theory, certain linear models are developed to express the contribution of peripheral circuits of cyclacenes into their total \pi-electron energies, which explain why cyclacenes exhibit the cryptoannulenic behavior as their peripheral circuits which are annulenic in character.
Spectroscopic Studies Of Charge-Transfer Complexes Of 2,3-Dichloro-5,6-Dicyano-P-Benzo-Quinone, M. S. Subhani̇, N. K. Bhatti̇, M. Mohammad, A. Y. Khan
Spectroscopic Studies Of Charge-Transfer Complexes Of 2,3-Dichloro-5,6-Dicyano-P-Benzo-Quinone, M. S. Subhani̇, N. K. Bhatti̇, M. Mohammad, A. Y. Khan
Turkish Journal of Chemistry
Charge-transfer complexes of 2,3-dichloro-5, 6-dicyano-p-benzoquinone (DDQ) p-acetotoluidide, acetanilid, biphenyl and naphthalene were studied and their absorption spectra in solution were recorded. Absorption spectral data were obtained in CH_2Cl_2, CHCl_3, CCl_4 and mixture (CH_2Cl_2 + V) at different temperatures. Two charge-transfer bands were observed in each case. Spectral characterization of these complexes was determined and correlated with the ionization potential of the donor. Variation in thermodynamic parameters were also found to be due to change in donor and solvent.
Atmospheric Deposition Of Pb, Zn, Cu, And Cd In Amman, Jordan, Kamal A. Momani, Anwar G. Jiries, Qasem M. Jaradat
Atmospheric Deposition Of Pb, Zn, Cu, And Cd In Amman, Jordan, Kamal A. Momani, Anwar G. Jiries, Qasem M. Jaradat
Turkish Journal of Chemistry
Atmospheric samples were collected using a low-volume air sampler and dustfall containers during the summer of 1995 at different sites in the city of Amman, Jordan. The heavy metal contents in settleable particles (dustfall) as well as in air particulates (suspended) were analyzed by graphite furnace atomic absorbation spectrophotometry. The atmospheric concentrations of Zn, Cu, Pb, and Cd were 344, 170, 291, and 3.8 ng/m$^3$, respectively. The levels of these elements in the dustfall deposition were 505, 94, 74 and 3.1 $\mu$g/g, respectively. The fluxes and dry deposition velocities of these heavy metals were determined and compared with the findings …
Impedance Measurements Of Polyester-Coated Galvanised Mild Steel In 10xacid Rainwater After An Accelerated Wet-Dry Test, İlyas Dehri̇
Impedance Measurements Of Polyester-Coated Galvanised Mild Steel In 10xacid Rainwater After An Accelerated Wet-Dry Test, İlyas Dehri̇
Turkish Journal of Chemistry
The variation of defective polyester-coated performance with time in 10xacid rain solution was investigated using electrochemical impedance spectroscopy. Measurements were carried out on samples after an accelerated atmospheric corrosion test. The impedance diagrams (Nyquist plots) were simulated using the EQUIVCRT program which was elaborated by Boukamp and the semi-ellipse model which was developed by Erbil. It has been shown that the defective coating resistance changes with time for the samples subjected to acid rainwater. The corrosion rate of coated metal also changes with time.
Synthesis Of A New Dihydropyridine Derivative Containing A Known Vasodilator Khellin, Gülgün Ayhan Kilcigi̇l, Meral Tunçbi̇lek, Rahmi̇ye Ertan, Kevser Erol, Engi̇n Yildirim
Synthesis Of A New Dihydropyridine Derivative Containing A Known Vasodilator Khellin, Gülgün Ayhan Kilcigi̇l, Meral Tunçbi̇lek, Rahmi̇ye Ertan, Kevser Erol, Engi̇n Yildirim
Turkish Journal of Chemistry
The synthesis and spasmolytic activity of a novel dihydropyridine derivative which contains a vasodilator furanochromone khellin at the 4^{th}$ position of the dihydropyridine ring via the Hantzsch method from khellin-2-carboxaldehyde is described.
The Effect Of Acetone On Calomel Formation On A Mercury Film Electrode Surface In Chloride Medium, F. Ni̇l Ertaş, H. İsmet Gökçel, Hüseyi̇n Tural
The Effect Of Acetone On Calomel Formation On A Mercury Film Electrode Surface In Chloride Medium, F. Ni̇l Ertaş, H. İsmet Gökçel, Hüseyi̇n Tural
Turkish Journal of Chemistry
In the presence of chloride ions, calomel formation takes place on the mercury thin film electrodes under open-circuit conditions, which leads to high base currents and erratic performance in ASV meas- urements. This study describes the effect of chloride concentration on the calomel formation on the surface by following the cathodic peak on the anodic scan. The effect of acetone on the surface reaction and baseline stability was studied. Application of the method with a sea water sample is also given.
Modification Of Polyester And Polyamide Fabrics By Different In Situ Plasma Polymerization Methods, T. Öktem, N. Seventeki̇n, H. Ayhan, Erhan Pi̇şki̇n
Modification Of Polyester And Polyamide Fabrics By Different In Situ Plasma Polymerization Methods, T. Öktem, N. Seventeki̇n, H. Ayhan, Erhan Pi̇şki̇n
Turkish Journal of Chemistry
In order to increase the hydrophilicities, and therefore to impart soil resistance and to improve dyeability, poly(ethylene terephthalate) (PET) and polyamide (PAm) fabrics were treated in low-temperature plasmas. Five different modification types were applied. Fabrics were directly treated in acrylic acid, water, air, O_2 and argon plasma. The plasma conditions (i.e., exposure time and discharge power) were changed to control the extent of plasma surface modification. Wettability, soil resistance and dyebility of PET fabrics were significantly improved by this method. More hydrophilic surfaces were created by all the methods.
Spectrophotometric Determination Of Selenium (Iv) Using Methdilazine Hydrochloride, Mahaveer B. Melwanki, Jaldappa Seetharamappa
Spectrophotometric Determination Of Selenium (Iv) Using Methdilazine Hydrochloride, Mahaveer B. Melwanki, Jaldappa Seetharamappa
Turkish Journal of Chemistry
Methdilazine hydrochloride is proposed as a selective and sensitive reagent for the spectrophotometric determination of selenium (IV). The reagent forms a red radical cation by selenimum (IV) in hydrochloric acid medium and exhibits an absorption maximum at 513 nm. Beer's law is valid over the concentration range 0.1-2.3 mg1^{-1} of selenium (IV). Sandell's sensitivity of the reaction is found to be 3.57 ng cm^{-2} and the molar extinction coefficient is 9.32 x 10^4 1 mol^{-1} cm^{-1} at 513 nm. The effects of acidity, reagent concentration, temperature and diverse ions upon the absorbance of the red species are critically assessed. The …
Polarographic Determination Of Fluvoxamine Maleate In Tablets, Fi̇kri̇ye Elmali, Güzi̇n Alpdoğan, Sidika Sungur, Şule Aycan
Polarographic Determination Of Fluvoxamine Maleate In Tablets, Fi̇kri̇ye Elmali, Güzi̇n Alpdoğan, Sidika Sungur, Şule Aycan
Turkish Journal of Chemistry
The differential pulse polarographic (DPP) method was developed for the determination of fluvoxamine maleate (I). At pH = 3. 7, (I) give a peak at - 0. 73 V in aqueous solution. The developed method was applied to the assay of the drug substance in commercial tablet formulations. The results were statistically compared with those obtained by reference methods (HPLC and direct current polarographic method) using t- and F- tests at 95 % confidence level.
Electroreduction Of Some Diazine And Triazine Pesticides At The Dropping Mercury Electrode, Petr Zuman, Marina Privman, Masami Shibata, Jiri Ludvik
Electroreduction Of Some Diazine And Triazine Pesticides At The Dropping Mercury Electrode, Petr Zuman, Marina Privman, Masami Shibata, Jiri Ludvik
Turkish Journal of Chemistry
Electroanalytical methods enable determination of electroactive species in nonhomogeneous systems, as limiting currents are little affected by the presence of solid and colloidal particles. An example of such applications of electrochemical methods are studies of binding of toxic substances, such as pesticides, on slightly soluble polymers, such as lignin. To successfully apply polarographic methods for following free pesticides in a slurry of lignin, it is first necessary in principle to elucidate the electrochemical processes involved. In aqueous buffered solutions the electron transfers, in which organic compounds participate, are in the majority of cases accompanied by chemical reactions. To elucidate the …
Synthetic Metal Alloys: Preparation Of Polyaniline/Polypyrrole Alloys In Protic Medium, Fati̇h Köleli̇, Meltem Düdükcü, Yasemi̇n Arslan
Synthetic Metal Alloys: Preparation Of Polyaniline/Polypyrrole Alloys In Protic Medium, Fati̇h Köleli̇, Meltem Düdükcü, Yasemi̇n Arslan
Turkish Journal of Chemistry
Pyrrole and aniline solutions were mixed in different ratios and oxidized under anodic conditions on Pt surface in protic medium. The electrocopolymerization and electrochemical properties of these alloys were investigated. Current-potential diagrams of polyaniline (PA), polypyrrole (PP) and the resulting alloys were recorded and their electrochemical characterizations were identified. In-situ resistance measurements of synthesized alloys were carried out with a home-made apparatus. Conductivity of alloys showed changes depending on applied potential as intrinsic polymers. The electrochemical behaviour of homopolymers and alloys was studied at different temperatures.
A Convenient Synthesis Of Some 4-(Alkylamino)-4,5-Dihydro-1h-1,2,4-Triazol-5-Ones, Bahi̇tti̇n Kahveci̇, Aykut İki̇zler
A Convenient Synthesis Of Some 4-(Alkylamino)-4,5-Dihydro-1h-1,2,4-Triazol-5-Ones, Bahi̇tti̇n Kahveci̇, Aykut İki̇zler
Turkish Journal of Chemistry
A series of 3-alkyl-4-(arylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones, {\bfseries 6-10,} was obtained from the reaction of the corresponding 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones, {\bfseries 1,} with the appropriate aldehydes. 3-alkyl-4-(alkylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones of type {\bfseries 11-16} were synthesized from the selective reduction of compounds {\bfseries 5-10} with NaBH$_{4}$ in diglyme or DMSO medium as a general and convenient method.
Ion-Selective Membrane Electrode For The Determination Of A Novel Phenylpiperazine Antidepressant, Nefazodone, Arzum Erdem, Di̇lşat Özkan, Kağan Kerman, Burcu Meri̇ç, Tayfun Dalbasti, Mehmet Özsöz
Ion-Selective Membrane Electrode For The Determination Of A Novel Phenylpiperazine Antidepressant, Nefazodone, Arzum Erdem, Di̇lşat Özkan, Kağan Kerman, Burcu Meri̇ç, Tayfun Dalbasti, Mehmet Özsöz
Turkish Journal of Chemistry
The construction and performance characteristics of ion-selective membrane electrodes for a newly found phenylpiperazine antidepressant, Nefazodone (NFN), based on its ion-pair complexes with phosphotungstate (PT), tetraphenylborate (TPB), tungstosilicate (TS) and reineckate (RN) in a poly(vinyl chloride) (PVC) matrix are described. The best ion-selective electrode for determination of NFN contains NFN-PT as the active material. This electrode exhibits a Nernstian response (62.6 ± 0.4 mV per decade) in the range 1.5 x 10$^{-5}$ to 1.0 x 10^{-2} M NFN.HCl in solutions. The selectivity of this electrode to NFN in the presence of a number of sugar molecules, cations and drugs is …
Investigation Of The Synthesis Of Some Dehydroalanine Derivatives, Si̇bel Süzen, John Michael Williams
Investigation Of The Synthesis Of Some Dehydroalanine Derivatives, Si̇bel Süzen, John Michael Williams
Turkish Journal of Chemistry
Dehydroamino acids represent an important class of compound as they are key intermediates in unusual amino acid and in the design of peptides and are constituents of a variety of naturally occurring antibiotic and phytotoxic peptides. In view of the importance of proteins and peptides containing hydroxyamino acids and the problems associated with their synthesis and dehydration, an investigation was performed on model compounds in order to examine the difficulties of the dehydration reactions. The preparation and properties of the model dehydroalanine derivatives have been studied.
Hplc/Hydride Generation Aas Coupling For The Speciation Of Sb(Iii) And Sb(V) In Wastewaters, Nuray Şatiroğlu, Sema Bektaş, Ömer Genç, Haydar Hazel
Hplc/Hydride Generation Aas Coupling For The Speciation Of Sb(Iii) And Sb(V) In Wastewaters, Nuray Şatiroğlu, Sema Bektaş, Ömer Genç, Haydar Hazel
Turkish Journal of Chemistry
A comparative study was made with two HPLC columns of different lengths (PRP-X 100, 250 mm \( \times \) 4.1 mm id and PRP-X 100, 100 mm \( \times \) 4.1 mm id) coupled to HGAAS for the speciation of inorganic Sb(III) and Sb(V) species. The effects of eluent concentration and pH on the retention times of Sb species in both columns were investigated. The separation of Sb species was realized by using 50 mmol/L citrate solution at pH 4.0 as the eluent. The retention times were 2.0 min and 10.0 min in the 250 mm column, and 1.4 min …
Zinc Determination In Pleural Fluid, Nazan Demi̇r, Yaşar Demi̇r, Ebubeki̇r Bakan, İrfan Küfrevi̇oğlu
Zinc Determination In Pleural Fluid, Nazan Demi̇r, Yaşar Demi̇r, Ebubeki̇r Bakan, İrfan Küfrevi̇oğlu
Turkish Journal of Chemistry
In this study, an enzymatic zinc determination method was applied to pleural fluid, the basis of which was the regaining of the activity of apo carbonic anhydrase by the zinc present in the sample. The method was used for pleural fluid zinc determination in order to show the application to body fluids other than serum. For this purpose, pleural fluids were obtained from 20 patients and zinc concentrations were determined. Carbonic anhydrase was purified by affinity chromatography from bovine erythrocytes. The zinc present in its structure was removed by dialysis against dipicolinic acid, resulting in apoenzyme obtained at a ratio …
X-Ray Powder Diffraction And Ir Study Of Calcium Borophosphate Cabpo_5, A. Baykal, G. Gözel, Meral Kizilyalli, M. Toprak, R. Kniep
X-Ray Powder Diffraction And Ir Study Of Calcium Borophosphate Cabpo_5, A. Baykal, G. Gözel, Meral Kizilyalli, M. Toprak, R. Kniep
Turkish Journal of Chemistry
In this study, CaBPO_5 was synthesized by different solid state reactions than reported before and its X-ray powder diffraction and IR data were reported. In one of these solid state reactions BPO_4 was used as a phosphating agent. The examination of the X-ray powder diffraction data showed that this compound crystallized in a hexagonal system and the refined unit cell parameters were a = 6.684, c = 6.616(2) \AA, with Z=3 as reported before. From the observed reflections, the space group was determined as P3_121, and its density was found to be 3.15 g/cc. The X-ray powder diffraction and IR …
All Solid-State Contact Lead(Ii) Ion-Selective Pvc Membrane Electrode Using Dimethylene Bis(4-Methylpiperidinedithiocarbamate) Neutral Ionophore, İbrahi̇m Işildak
All Solid-State Contact Lead(Ii) Ion-Selective Pvc Membrane Electrode Using Dimethylene Bis(4-Methylpiperidinedithiocarbamate) Neutral Ionophore, İbrahi̇m Işildak
Turkish Journal of Chemistry
All solid-state contact PVC membrane electrodes for lead(II) ion were developed by using dimethylene bis(4-methylpiperidinedithiocarbamate) as neutral carrier and nitrophenyloctyl ether or dioctylsebacate as plasticizers. Response properties of the all solid-state contact PVC membrane electrode prepared with nitrophenyloctyl ether were better than those of the membrane electrode prepared with dioctylsebacate. The nitrophenyloctyl ether plasticized the all solid-state contact PVC membrane electrode and exhibited a good linear response of 30 mV/decade for lead(II) ion within the concentration ranges \( 0.1-5\times10^{-6} \) mol dm\( ^{-3} \) lead(II) nitrate, good selectivity over alkali, alkali-earth and transition metal ions including copper(II) ion by a …