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C2-Symmetric chiral diamine ligands for enantiomeric recognition of amino acid esters and mandelic acid by proton NMR titration method
(Tubitak Scientific & Technological Research Council Turkey, 2013) Aral, Hayriye; Aral, Tarik; Colak, Mehmet; Ziyadanogullari, Berrin; Ziyadanogullari, Recep
Two novel C-2-symmetric chiral diamines containing alpha-phenylethyl and alpha-(1-naphthyl)ethyl chiral subunits were prepared with quantitative yields. Enantiomeric recognition properties of these simple structured diamine ligands towards D- and L-amino acid esters and D- and L-mandelic acid were examined by the H-1 NMR titration method. These ligands exhibited strong complexation (with K-f up to 2481 M-1) and good enantioselectivity (up to K-L/K-D = 4.08) towards the mandelic acid enantiomers. The results show that simple structured and easily accessible acyclic C-2-symmetrical compounds can also be used for enantiomeric recognition of racemic amino acids and mandelic acid in addition to complex molecules such as crown ethers and other cyclic molecules.
Development of a novel amide-silica stationary phase for the reversed-phase HPLC separation of different classes of phytohormones
(Elsevier, 2013) Aral, Hayriye; Aral, Tarik; Ziyadanogullari, Berrin; Ziyadanogullari, Recep
A novel amide-bonded silica stationary phase was prepared starting from N-Boc-phenylalanine, cyclohexylamine and spherical silica gel (4 mu m, 60 angstrom). The amide ligand was synthesised with high yield. The resulting amide bonded stationary phase was characterised by SEM, IR and elemental analysis. The resulting selector bearing a polar amide group is used for the reversed-phase chromatography separation of different classes of thirteen phytohormones (plant hormones). The chromatographic behaviours of these analytes on the amide-silica stationary phase were compared with those of RP-C18 column under same conditions. The effects of different separation conditions, such as mobile phase, pH value, flow rate and temperature, on the separation and retention behaviours of the 13 phytohormones in this system were studied. The optimum separation was achieved using reversed-phase HPLC gradient elution with an aqueous mobile phase containing pH = 6.85 potassium phosphate buffer (20 mM) and acetonitrile with a 22 degrees C column temperature. Under these experimental conditions, the 12 phytohormones could be separated and detected at 230 or 270 nm within 26 min. (C) 2013 Elsevier B.V. All rights reserved.
HPLC Separation of Different Groups of Small Polar Compounds on a Novel Amide-Embedded Stationary Phase
(Springer Heidelberg, 2014) Aral, Hayriye; Aral, Tarik; Celik, K. Serdar; Ziyadanogullari, Berrin; Ziyadanogullari, Recep
Retention behaviors of an amide-embedded silica base stationary phase, which was recently developed by our group, were studied by using six different groups of small polar compounds including phenolic compounds, substituted anilines, chlorinated herbicides, Sudan dyes and some nucleotides and nucleosides in HPLC. The chromatographic behaviors of the prepared stationary phase for these analytes were compared with those of a commercially available reversed-phase column ACE C18 under same conditions. Among the six groups of analytes studied, the amide-silica stationary phase showed enhanced selectivity towards phenolic compounds, substituted anilines, Sudan dyes and herbicides under reversed-phase conditions and satisfactory selectivity towards nucleosides and nucleotides which could not be separated with ACE C18 column under HILIC conditions. Experimental data provided some evidence that functional groups on the stationary phases might have certain degrees of influence on selectivity possibly through secondary interactions with the model compounds. The retentions of the moderately polar compounds such as phenolic acids, anilines and herbicides on the stationary phase are higher than highly polar compounds such as nucleotides and nucleosides due to both the hydrophobic and hydrophilic interactions between the stationary phase and analytes. The quantitative determination of Sudan dyes (I, II, III, and IV) in red chilli peppers was performed. Many red chilli peppers were screened and three of them contained Sudans dyes.
ICP-OES Method for the Determination of Fe, Co, Mn, Cu, Pb, and Zn in Ore Samples From the Keban Region Using Experimental Design and Optimization Methodology
(Atomic Spectroscopy Press Ltd, 2016) Orala, Elif Varhan; Ziyadanogullari, Berrin; Aydin, Firat; Dinc, Erdal; Ziyadanogullari, Recep
A new approach based on the use of inductively coupled plasma optical emission spectrometry (ICP-OES) is presented for the quantitative determination of Fe, Co, Mn, Cu, Pb, and Zn in ore samples obtained from the Keban Region, Turkey. A 33 full factorial design with 27 sample runs was used to find the optimal sequential extraction conditions for the analysis of these samples. Under optimized conditions for each step of the sequential extraction procedure, calibration curves for the respective metals were obtained by measuring the absorbance values at 238.2 nm for Fe, 228.6 nm for Co, 257.6 nm for Mn, 327.4 nm for Cu, 220.4 nm for Pb, and 206.2 nm for Zn. The proposed ICP-OES method was successfully applied to the quantitative analysis of real ore samples containing Fe, Co, Mn, Cu, Pb, and Zn. Good agreement was found for the analytical results of these metals.
Nano-hemoglobin film based sextet state biomemory device by cross-linked photosensitive hapten monomer
(Elsevier Science Bv, 2018) Guzel, Remziye; Ersoz, Arzu; Ziyadanogullari, Recep; Say, Ridvan
In this study, a biomemory device, consisting of hemoglobin (Hb) cross-linked by MACys-Ru(bipyr)(2)-MACys) photosensitive monomer cross-linkers, which have memory effect through both Ru3+/2+ in hapten monomer and Fe3+/2+ in redox active center of Hb through multi-charge transfer mechanism, has been improved. Cyclic voltammetry (CV) has been used to determine the redox property of the Hb cross-linked MACys-Ru(bipyr)(2)-MACys) hapten. Three memory functions, writing, reading and erasing of the fabricated biomemory device, have been accomplished by chronoamperometry (CA) and open-circuit potential amperometry (OCPA). The reliability and repeatability of the biodevice consisting of the p(Hb-co-MACys-Ru(bipyr)(2)-MACys) sextet state bio-memory layer have been analysed. The Hb film based biodevice on gold electrodes has shown >= 2 months the retention time and switched until 10(6) times continuous cycling without degradation in efficiency. Other hand, the topography of p(Hb-co-MACys-Ru(bipyr)(2)-MACys) layer on the gold surface has investigated by scanning electron microscopy (SEM) and EDX data.
A new method for preconcentration of Th(IV) and Ce(III) by thermophilic Anoxybacillus flavithermus immobilized on Amberlite XAD-16 resin as a novel biosorbent
(Elsevier Science Bv, 2017) Yener, Ismail; Oral, Elif Varhan; Dolak, Ibrahim; Ozdemir, Sadin; Ziyadanogullari, Recep
A novel approach has been improved for the preconcentration of Th(IV) and Ce(III) by using thermophilic Anoxybacillus flavithermus which were immobilized on Amberlite XAD-16 resin and analyzed by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). The concentration of Th(IV) and Ce(III), the eluent type and volume, the pH of model solutions, influences of matrix interference parameters, and flow rate were analyzed and optimized extraction conditions were determined. The optimum pH for quantitative sorption of Th(IV) and Ce(III) was found as 7.0 and elution of Th(IV) and Ce(III) from mini-columns was studied with 1.0 mol L-1, 5 mL HNO3 with recoveries from 100%. The precision of this method was validated by comparing the analytical recovery and certified reference materials (IAEA Soil-7). Finally, this enrichment method was used to determine Th(IV) and Ce(III) in bastnaesite ore sample. (C) 2017 Elsevier B.V. All rights reserved.
A New Preconcentration Method for the Determination of Pb and Ni in Real Samples by Using Amberlite XAD-16 Functionalized With 1,6-bis(2-carboy aldehyde phenoxy)butane
(Atomic Spectroscopy Press Ltd, 2019) Oral, Elf Varhan; Erdogan, Sait; Temel, Hamdi; Ziyadanogullari, Berrin; Ziyadanogullari, Recep
In this study, a steady chelating resin matrix was formed by tying 1,6-bis(2-carboxy aldehyde phenoxy) butane to Amberlite XAD-16 resin by a -C=N- group. This synthesized adsorbent was placed into a minicolumn to separate and preconcentrate the lead and nickel ions before their determination by flame atomic absorption spectrometry (PARS). The effects of many parameters on the preconcentration method were examined. The optimal pH value for the quantitative absorption of lead and nickel was pH 5.0. The percentage of recovery for lead and nickel was 99 +/- 1.15% and 100 +/- 2.70%, respectively. The detection limits of lead and nickel utilizing FAAS (3s, N=20) were 1.47 and 1.16 mu g/L, respectively. The effects of some matrix components on the recovery were analyzed. The suggested method was utilizied to determine lead and nickel in real water samples obtained from the River Tigris in Turkey, as well as in automobile exhaust particles, Romaine letnice, and parsley. The accuracy of the proposed method was verified by using the standard addition method and the standard reference material NCS-DC 73350 Poplar Leaves.
Recovery of hydrogen sulfide, copper and cobalt from the samples after conversion of pyrite to FeS
(Asian Journal Of Chemistry, 2007) Ziyadanogullari, Recep; Aydin, Firat
The aim of this study was to recover hydrogen sulfide, copper and cobalt from the pyrite samples provided from Ergani and Kure Copper Mining Co., Turkey. The samples were subjected to two different processes: in first process, the sample was mixed with different rates of iron at varying temperature and time and then subjected to roasting process in closed vessel system. In the second process, the sample was directly exposed to roasting process in a closed vessel system. In both processes, conversion values of pyrite into FeS were determined. After direct roasting the pyrite at 725 degrees C for 1 h, the conversion rate of pyrite into FeS was found to be 98.9 +/- 0.1 %. By addition of H2SO4 the sample converted into FeS structure, H2S gas was formed. Through reaction of water with the residue remaining after separation of H2S gas from solid phase, iron. passed into solution, while copper and cobalt remained in the solid phase. In order to recover cobalt and copper from the sample in which iron was removed, two procedures were followed; first procedure includes taking cobalt and copper in solution by direct roasting the sample in air atmosphere at 600 degrees C. The second process involves taking cobalt and copper in solution medium trough roasting the sample under the same conditions after enrichment with flotation. As a result of roasting the samples enriched with flotation, the optimal conditions in which copper and cobalt could be taken into solution with high yield were determined.
Reduction of Cr(VI) in aqueous solutions by natural and roasted pyrite
(Asian Journal Of Chemistry, 2007) Dolak, Ibrahim; Tegin, Ibrahim; Guzel, Remziye; Ziyadanogullari, Recep
In present study, the effects of parameters such as acid concentration of the medium, amount of pyrite, initial Cr(VI) concentration, contact time, temperature and particle size of pyrite on the reduction of Cr(VI) by discontinuous experiments using raw pyrite and the pyrite samples roasted at high temperatures in vacuum were examined. Considering that the pyrite sample converted FeS structure which has much higher reduction ability and is more homogeneous by roasting at high temperatures in vacuum, it was determined that using the pyrite sample in this way for the Cr(VI) reduction was much more efficient.
Removal and Preconcentration of Pb(II), Cr(III), Cr(VI) from the Aqueous Solution and Speciation of Cr(III)-Cr(VI) by Using Functionalized Amberlite XAD-16 Resin with Dithioethylenediamine
(Asian Journal Of Chemistry, 2010) Dolak, Ibrahim; Tegin, Ibrahim; Guzel, Remziye; Ziyadanogullari, Recep
Amberlit XAD-16 was functionalized using dithioethylenediamine as a ligand and characterized by elemental analysis and FTIR spectroscopy. The effects of contact time, pH, electrolyte and the concentration of eluent on separation and preconcentration of Pb(II), Cr(III) and Cr(VI) were studied. In addition, the batch capacity for each ion was determined under the optimum conditions. The preconcentration yields of Pb(II), Cr(III) and Cr(VI) were found to be 96.60 +/- 3.02, 102.20 +/- 3.00 and 100.64 +/- 2.24 %, respectively, with 500 times preconcentration factor under the optimum conditions. The speciation of Cr(III)-Cr(VI) was studied, it was determined that Cr(III) separated in 93.24 +/- 2.21 % yield from the solution containing Cr(III)-Cr(VI) by using Amberlit XAD-16-dithioethylenediamine and Cr(VI) remained in the solution at pH 4, while Cr(VI) separated in 101.43 +/- 3.09 % yield from the solution containing Cr(III)-Cr(VI) and Cr(III) remained in the solution. at pH 7.50 by using Amberlit XAD-16-dithioethylenediamine-Pb(II).
Removal and Preconcentration of Pb(II), V(V), Cr(VI) from the Aqueous Solution and Selective Separation of V(V)-Cr(VI) by Using Functionalized Amberlite XAD-16 Resin with Dithioethylenediamine
(Asian Journal Of Chemistry, 2010) Dolak, Ibrahim; Tegin, Ibrahim; Guzel, Remziye; Ziyadanogullari, Recep
Amberlit XAD-16 was functionalized using dithioethylenediamine as a ligand. and characterized by elemental analysis and FTIR spectroscopy. The effects of contact time, pH, electrolyte and the concentration of eluents on separation and preconcentration of Pb(II), Cr(VI) and V(V) were studied. In addition, the batch capacity for each ion was determined under the optimum conditions. The preconcentration yields of Pb(II), Cr(VI) and V(V) were found to be 96.60 +/- 3.02, 100.64 +/- 2.24 and 98.20 +/- 3.00 %, respectively, with 500 times preconcentration factor under the optimum conditions. The selective separation of Cr(VI)-V(V) was studied in terms of pH. It was determined that V(V) separated in 98.24 +/- 1.21 % yield from the solution containing Cr(VI)-V(V) and Cr(VI) remained in the solution at pH 2.5, while Cr(VI) separated in 101.43 +/- 3.09 % yield from the solution containing Cr(VI)-V(V) and V(V) remained in the solution at pH 8.5 by using Amberlit XAD-16-dithioethylenediamine -Pb(II).
Separation of copper, cobalt and iron in solution obtained from copper ore
(Asian Journal Of Chemistry, 2007) Aymn, Firat; Ziyadanogullari, Recep
The aim of this study is to recover copper, cobalt and iron from roasted copper ore which contains copper, cobalt and iron in soluble forms. The solution was evaporated and enriched by copper and the separation process was applied. Basically, copper was separated from the solution by the process of electrolysis, using Pt electrodes at 50-60 degrees C. During the electrolysis process, a constant 2.69 V voltage was applied between electrodes. The remaining solution of electrolysis process was evaporated and a mixture of CoSO4, FeSO4 and H2SO4 was remained. In order to separate cobalt and iron ions from the mixture, 96 % of ethyl alcohol solution was used and pure cobalt was left in a solid form of CoSO4 center dot 7H(2)O.
Separation of Mo, Cu, Zn and Pb from concentrates of fluorite ore containing molybdenum
(Asian Journal Of Chemistry, 2007) Ziyadanogullari, Recep; Akguen, Abuzer; Tegin, Ibrahim; Guezel, Remziye
This study deals with the separation of Mo, Cu, Zn and Ph from concentrates of a flotation process of Elazig region fluorite ore containing of molybdenum. The original ore contained (%) 1.08 Mo, 0.05 Cu, 1.12 Zn, 1.20 Ph and 12 F. The ore concentrate after flotation contained (%) 19.46 Mo, 0.87 Cu, 4.54 Zn and 2.65 Pb. The fluorite itself was separated and left in the residue during flotation process. A hydrometallurgical concentration process was used for the separation of Mo, Cu, Zn and Ph. In view of the existence of sulfide, the concentrate was roasted at 600 degrees C and the concentrations of dissolved ions were investigated. The result was not fruitful. In the following work, the concentrates were roasted at various temperatures and durations and the samples were later treated in a autoclave at 225 degrees C wi,th 15 M H2SO4. Under suitable set of conditions Mo, Cu and Zn were dissolved and Pb was left behind in the form of PbSO4. The molybdenum in the solution was separated from copper and zinc by an extraction process by using alamine 336 (trioctylamine). (NH4)(2)S was used to separate molybdenum from the organic phase. Due to the presence of the other ions such as vanadium, tantalum and niobium, the separation of molybdenum could not be achieved with H2S, but (NH4)(2)S was utilized in the process.
Synthesis and Preconcentration of Amberlite XAD-4 Resin Modified by Dithioethylenediamine
(Asian Journal Of Chemistry, 2009) Dolak, Ibrahim; Tegin, Ibrahim; Guezel, Remziyfe; Ziyadanogullari, Recep
In the present work, Amberlite XAD-4 copolymer resin modified by rubeanic acid was synthesized for separation and preconcentration of Cu(II), Co(II), Ni(II)), Cd (II) and Mn(II). The optimization procedure for analytical parameters including pH, contact time, batch capacity, etc. was examined in order to obtain quantitative recoveries of metal ions. Preconcentration yields of Cu(II), Co(II), Ni(II), Cd (II) and Mn(II) by Amberlite XAD-4-dithioethylenediamine copolymer resin were found as 103.3 +/- 2.6, 96.8 +/- 1.7, 102.0 +/- 3.0, 90.3 +/- 1.7 and 97.2 +/- 2.4 %, respectively. Batch capacity of Cu(II), Co(II), Ni(II), Cd(II) and Mn(II) by Amberlite XAD-4-dithioethylenediamine copolymer resin was determined as 0.1243 +/- 0.0036, 0.2057 +/- 0.0034, 0.2323 +/- 0.0043, 0.1757 +/- 0.0025 and 0.1888 +/- 0.0034 mmol g(-1) resin, respectively. The preconcentration factor was 500 for Cu (II), Co (II), Ni(II), Cd(II) and Mn(II).
Synthesis and spectral characterization of macrocyclic Schiff base by reaction of 2,6-diaminopyridine and 1,4-bis(2-carboxyaldehydephenoxy)butane and its CuII, NiII, PbII, CoIII and LaIII complexes
(Springer, 2007) Ilhan, Salih; Temel, Hamdi; Ziyadanogullari, Recep; Sekerci, Memet
A new macrocyclic ligand, 1,3,5-triaza-2,4:7,8:15,16-tribenzo-9,15-dioxacycloheptadeca-1,5-diene (L) was synthesized by reaction of 2,6-diaminopyridine with 1,4-bis(2-carboxyaldehydephenoxy)butane. Then, its Cu-II, Ni-II, Pb-II,and Co-III and La-III complexes were synthesized by the template effect by reaction of 2,6-diaminopyridine and 1,4-bis(2-carboxyaldehydephenoxy)butane and Cu(NO3)(2)center dot 3H(2)O, Ni(NO3)(2) center dot 6H(2)O, Pb(NO3)(2), Co(NO3)(2) center dot 6H(2)O, La(NO3)(3) center dot 6H(2)O, respectively. The ligand and its metal complexes were characterized by elemental analysis, IR, H-1- and C-13-n.m.r., UV-vis spectra, magnetic susceptibility, thermal gravimetric analysis, conductivity measurements and mass spectra. All complexes are diamagnetic and the Cu-II complex is binuclear. The Co-II complex was oxidised to Co-III.
Synthesis of a mixed-model stationary phase derived from glutamine for HPLC separation of structurally different biologically active compounds: HILIC and reversed-phase applications
(Elsevier Science Bv, 2015) Aral, Tarik; Aral, Hayriye; Ziyadanogullari, Berrin; Ziyadanogullari, Recep
A novel mixed-mode stationary phase was synthesised starting from N-Boc-glutamine, aniline and spherical silica gel (4 mu m, 60 angstrom). The prepared stationary phase was characterized by IR and elemental analysis. The new stationary phase bears an embedded amide group into phenyl ring, highly polar a terminal amide group and non-polar groups (phenyl and alkyl groups). At first, this new mixed-mode stationary phase was used for HILIC separation of four nucleotides and five nucleosides. The effects of different separation conditions, such as pH value, mobile phase and temperature, on the separation process were investigated. The optimum separation for nucleotides was achieved using HILIC isocratic elution with aqueous mobile phase and acetonitrile with 20 degrees C column temperature. Under these conditions, the four nucleotides could be separated and detected at 265 nm within 14 min. Five nucleosides were separated under HILIC isocratic elution with aqueous mobile phase containing pH=3.25 phosphate buffer (10 mM) and acetonitrile with 20 degrees C column temperature and detected at 265 nm within 14 min. Chromatographic parameters as retention factor, selectivity, theoretical plate number and peak asymmetry factor were calculated for the effect of temperature and water content in mobile phase on the separation process. The new column was also tested for nucleotides and nucleosides mixture and six analytes were separated in 10 min. The chromatographic behaviours of these polar analytes on the new mixed-model stationary phase were compared with those of HILIC columns under similar conditions. Further, phytohormones and phenolic compounds were separated in order to see influence of the new stationary phase in reverse phase conditions. Eleven plant phytohormones were separated within 13 min using RP-HPLC gradient elution with aqueous mobile phase containing pH=2.5 phosphate buffer (10 mM) and acetonitrile with 20 degrees C column temperature and detected at 230 or 278 nm. The best separation conditions for seven phenolic compounds was also achieved using reversed-phase HPLC gradient elution with aqueous mobile phase containing pH=2.5 phosphate buffer (10 mM) and acetonitrile with 20 degrees C column temperature and seven phenolic compounds could be separated and detected at 230 nm within 16 min. (C) 2014 Elsevier B.V. All rights reserved.
Synthesis, characterization and structure effects on preconcentration and extraction of N,N?-bis-(salicylaldehydene)-1,4-bis-(p-aminophenoxy) butane towards some divalent cations
(Elsevier, 2008) Ziyadanogullari, Berrin; Cevizici, Deniz; Temel, Hamdi; Ziyadanogullari, Recep
Separation with solvent extraction of Cu(II), Co(II) and Ni(II) from aqueous solution using N,N'-bis-(salicylaldehydene)-1,4-bis-(p-aminophenoxy)butane (H2L) as the new extractant has been studied. The new Schiff base, was synthesized by reaction of 1,4-bis-(p-aminophenoxy)butane and salicylaldehyde. Microanalytical data, elemental analysis, UV-vis H-1 NMR and C-13 NMR spectra and IR-spectra were used to confirm the structures. The extractability and selectivity of divalent cations was evaluated as a function of relationship between distribution ratios of the metal and pH or ligand concentration. Cu+2 showed the highest extractability and selectivity at pH 7.8, whereas Ni+2 and Co+2 showed at pH 9.2. From the loaded organic phase, Cu(II), Co(II), Ni(II) stripping were carried out in one stage with aqueous acid solution including various concentrations of HCl The stripping efficiency was found to be quantitative in case of 1.5 M HCl From quantitative evaluation of the extraction equilibrium data, it has been deduced that the complexes extracted are the simple 1:1 chelates, CuL, CoL, NiL. (c) 2007 Elsevier B.V. All rights reserved.

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