Yazar "Ziyadanogullari, Berrin" seçeneğine göre listele
Listeleniyor 1 - 20 / 21
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Anoxybacillus sp. SO B1-Immobilized Amberlite XAD-16 for Solid-Phase Preconcentration of Cu(II) and Pb(II) and Their Determinations by Flame Atomic Absorption Spectrometry(Taylor & Francis Inc, 2015) Oral, Elif Varhan; Ozdemir, Sadin; Dolak, Ibrahim; Okumus, Veysi; Dundar, Abdurrahman; Ziyadanogullari, Berrin; Aksoy, ZehraA new method for the determination of Cu(II) and Pb(II) by flame atomic absorption spectrometry (FAAS) after preconcentrating on a column containing Anoxybacillus sp. SO B1-immobilized Amberlite XAD-16 was developed. The functional groups of Anoxybacillus sp. SO B1 immobilized on Amberlite XAD-16 were characterized in KBr tablets by Fourier transform infrared (FT-IR) spectrometry. Various parameters such as pH, amount of the adsorbent, eluent type and volume, and flow rate of the sample solution were studied. The optimum pH values of quantitative sorption for Cu(II) and Pb(II) were found to be pH 7.0 and 5.0 and Cu(II) and Pb(II) ions could be quantitatively eluted with 5.0ml of 1.0mol L-1 HCI and 10.0ml of 0.25mol L-1 HNO3, respectively. Recoveries of Cu(II) and Pb(II) were found to be 100.9 +/- 1.57% and 100.3 +/- 0.49% (N = 5), the limits of detection of Cu(II) and Pb(II) in the determination by FAAS (3s, N = 10) were found to be 0.8 and 1.6 mu g L-1, respectively. The proposed enrichment method was applied for metal ion determination from water samples such as two parts of Tigris River water in Diyarbakir and Elazig, Lake of Hazar in Elazig, and tap water in Diyarbakir. Furthermore, the accuracy of the proposed method was verified by studying the analytical recovery and by analyzing certified reference material (NCS-DC 73350 leaves of poplar).Öğe 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, RecepTwo 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.Öğe Comparison of binding properties of a novel non-steroidal anti-inflammatory agent and ibuprofen to cyclooxygenase-1 and cyclooxygenase-2 enzymes by saturation transfer difference nuclear magnetic resonance(Canadian Science Publishing, Nrc Research Press, 2018) Binbay, Nil E.; Ziyadanogullari, BerrinSaturation transfer difference nuclear magnetic resonance is a ligand-based screening technique that focuses directly on the physical interaction of a macromolecule (protein, enzyme, etc.) and a small ligand. It is a powerful tool in pharmaceutical research. Here, a comparison is reported of the binding characteristics of ibuprofen and a novel anti-inflammatory agent to cyclooxygenase-1 and cyclooxygenase-2 enzymes as an application of saturation transfer difference nuclear magnetic resonance. It has been shown that this novel agent is capable of binding to both isoforms of the cyclooxygenase enzymes. It has also been reported that novel agent binds better to cyclooxygenase-2.Öğe Comparison of Methods for the Preconcentration of Cadmium (II) Using Amberlite XAD-16 Resin Modified with Anoxybacillus caldiproteolyticus and Geobacillus stearothermophilus as Novel Biosorbents(Taylor & Francis Inc, 2020) Enez, Baris; Oral, Elif Varhan; Fincan, Sema Aguloglu; Ziyadanogullari, BerrinThe isolation, identification and characterization of bacteria obtained from soil of Ergani Makam Mountain were performed and the results revealed that the bacteria were thermophilic Anoxybacillus caldiproteolyticus. The characterized bacteria and purchased Geobacillus stearothermophilus were immobilized on Amberlite XAD-16 in order to prepare two biosorbents for preconcentration experiments for the determination of cadmium (II) ions. The produced biosorbents were enriched separately using mini-columns and the analyte was determined by flame atomic absorption spectrometry. The effects of solution parameters were investigated for the separation and preconcentration yields. The recovery efficiencies of Amberlite XAD-16 immobilized separately with A. caldiproteolyticus and G. stearothermophilus were determined to be 98.23 +/- 2.40 and 98.93 +/- 1.3 (n = 5) for the optimum working conditions, respectively. Moreover, the Cd (II) ion was recovered with 10 mL of 1 mol L-1 of HCl and 2 mL of 0.5 mol L-1 HNO3 solutions. The optimum working conditions were determined to be at pH 6.0 and a flow rate of 2 mL min(-1) for both biosorbents. The recovery efficiencies of matrix ions were characterized to investigate the feasibility of the developed preconcentration methods. The accuracy of the proposed methods were controlled by analyzing a SCP Science EnviroMAT Waste Water, Low (EU-L-2) certified reference material. The obtained results were comparable to the certified values. These methods were also applied to the analysis of water samples from Dicle River, Hazar Lake and Diyarbakir tap water for Cd (II).Öğe Determination of Trace Elements in Turkish Wines by ICP-OES and HG-ICP-OES(Atomic Spectroscopy Press Ltd, 2010) Aydin, Isil; Yuksel, Uyan; Guzel, Remziye; Ziyadanogullari, Berrin; Aydin, FiratThe aim of this work was to determine the concentration of toxic metals in wine samples from different regions in Turkey using ICP-OES and HG-ICP-OES, and comparing the results with reports from other researchers. Ten samples each of white wines and red wines were obtained at a local supermarket and analyzed for Ca, K, Cr, Mn, Sn, Zn, Cu, Fe, Ni, Mg, Al, and Co by inductively coupled plasma optical emission spectrometry (ICP-OES), and for Hg, Pb, and Cd by hydride generation combined with inductively coupled plasma optical emission spectrometry (HG-ICP-OES). The concentrations found in red and white wines were, respectively: Cd: 0.017 and 0.016 mu g L-1; Ply 0.021 and 0.030 mu g L-1; Hg: <0.005 and <0.01 mu g L-1; Ca: 44.118 and 42.195 mg L-1, Cr: 0.056 and 0.0584 mg L--1,L- K: 1169 and 986 mg L--1,L- Mn: 1.564 and 0.118 mg L--1,L- Sn: 0.098 and 0.089 mg L--1,L- Zn: 0.665 and 0.473 mg L-1, Cu: 0.079 and 0.126 mg L-1, Fe: 1.024 and 1.005 mg L-1, Ni: 0.036 and 0.051 mg L-1, Mg: 78 and 68 mg L-1, Al: 0.524 and 0.524 mg L-1, Co: 0.214 and 0.134 mg L-1, The accuracy of the method was verified using the standard reference material NRCSLRS-4 River Water. The analytical values obtained are comparable with those reported by other researchers.Öğe 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, RecepA 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.Öğe Development of molecular imprinting-based smart cryogels for selective recognition and separation of serum cytochrome-c as a biochemical indicator(Elsevier Sci Ltd, 2021) Canpolat, Gurbet; Dolak, Ibrahim; Onat, Ruken; Kecili, Rustem; Baysal, Zubeyde; Ziyadanogullari, Berrin; Ersoz, ArzuThe recognition and detection of proteins has an important role in the fields of biochemistry and medicine in term of diagnosis and prognosis. In this study, molecularly imprinted cryogel (MIP) was synthesized for the selective recognition of Cytochrome-c (Cyt-c) by cryopolymerization techniques with the lanthanide-chelate approach using (MAAP)2-Ce(III) as complex functional monomer and Cyt-c as a template protein. The incorporation of template with monomer was characterized by near- infrared (Near-IR) spectroscopy. The binding capacity was optimized in accordance with numerous experimental parameters including pH, initial Cyt-c concentration, flow rate, temperature and ionic strength. As a result, the maximum binding capacity reached to 98.33 mg g-1 in a buffer system with a pH of 6.0. Beside of the excellent reusability performance of prepared MIP, it was successfully applied to separation of template Cyt-c in the existence of hemoglobin (Hb) and myoglobin (Mb) chosen as interfering proteins. The relative selectivity constants of the Cyt-imprinted polymer were determined as 13.84 for the Cyt/Mb pair and 16.05 for the Cyt/Hb pair. Consequently, a high selectivity, simple and cheap strategy for efficient separation of proteins was provided with this novel MIP cryogel.Öğe 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, RecepRetention 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.Öğe 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, RecepA 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.Öğe Ion imprinted cryogel-based supermacroporous traps for selective separation of cerium(III) in real samples(Elsevier, 2018) Kecili, Rustem; Dolak, Ibrahim; Ziyadanogullari, Berrin; Ersoz, Arzu; Say, RidvanThis study demonstrates the preparation and characterization of a novel ion imprinted cryogel which exhibits high affinity and selectivity towards Ce(III) ions in aqueous solutions and bastnasite ore samples. 2-Hydroxyethyl methacrylate (HEMA) and N-methacryloylamido antipyrine (MAAP) were used as functional monomers for the preparation of Ce(III) imprinted cryogel. The effects of various factors such as initial Ce(III) concentration, flow rate, pH, interaction time and ionic strength on the Ce(III) binding to the prepared ion imprinted cryogels were also studied. The binding equilibrium for Ce(III) is obtained in 30 min at the flow rate of 0.5 mL/min. The maximum binding capacity of the prepared ion imprinted cryogel towards Ce(III) is obtained as 36.58 mg/g at optimum conditions. The selectivity of the prepared ion imprinted cryogel towards Ce(III) in the presence of other possible interfering lanthanide ions such as La(III) and Nd(III) were also performed. The obtained results showed that the prepared ion imprinted cryogel exhibits high selectivity and sensitivity towards Ce(III) ions. The limit of detection (LOD) was found as 50 mu g/L. (C) 2018 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.Öğe Molecularly imprinted affinity cryogels for the selective recognition of myoglobin in blood serum(Elsevier Science Bv, 2018) Dolak, Ibrahim; Kecili, Rustem; Onat, Ruken; Ziyadanogullari, Berrin; Ersoz, Arzu; Say, RidvanThe present work demonstrates the selective recognition of myoglobin in human serum in the presence of various competitive proteins such as lysozyme, cytochrome c and hemoglobin by using molecularly imprinted affinity cryogels. The imprinted affinity cryogels towards myoglobin were prepared by using cryopolymerization technique. For this purpose, N-methacryloylamido antipyrine (MAAP)-Ce(III) and myoglobin were used as the complex functional monomer and template molecule, respectively. (MAAP)-Ce(III) complex functional in the imprinted cryogel provided a luminescence feature to the cryogel and the detection of the myoglobin was successfully achieved by UV-VIS-Near Infrared (UV-VIS-NIR) Spectroscopy. The effects of some variables such as initial myoglobin concentration, temperature, pH and ionic strength on myoglobin binding to the prepared cryogels were studied. The myoglobin binding capacity of the prepared cryogels was determined to be 68 mgg(-1). Myoglobin binding to the cryogels in the presence of competitive proteins lysozyme, cytochrome c and hemoglobin were also performed. The imprinted cryogels exhibited high selectivity towards myoglobin and the obtained binding order under competitive conditions was myoglobin > lysozyme > cytochrome c > hemoglobin. (C) 2018 Elsevier B.V. All rights reserved.Öğe 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, RecepIn 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.Öğe A novel lanthanide-chelate based molecularly imprinted cryogel for purification of hemoglobin from blood serum: An alternative method for thalassemia diagnosis(Elsevier Sci Ltd, 2020) Dolak, Ibrahim; Canpolat, Gurbet; Onat, Ruken; Kecili, Rustem; Baysal, Zubeyde; Ziyadanogullari, Berrin; Ersoz, ArzuPurification and analyzing of proteins is an essential means for understanding their function and diseases associated with their lack or defect. In this research, a new lanthanide-chelate based molecularly imprinted polymer (MIP) was synthesized for selective separation of Hemoglobin (Hb) from human serum in the presence of various interference molecules. The Hb-imprinted polymer was prepared by using complex functional monomer N-methacryloylamido antipyrine (MAAP)-Ce(III) and 2-Hydroxyethyl methacrylate (HEMA) in accordance of cryopolymerization techniques. The nonimprinted cryogel (NIP) was also prepared at same polymerization conditions in the absence of template Hb molecule. The effects of pH, initial Hb concentration, flow rate, temperature and ionic strength on the binding capacity of both imprinted and nonimprinted cryogels was investigated. The maximum binding capacity for the MIP column was found to be as 79.41 mg g(-1) dry cryogel, that is four times higher than the NIP column under the optimum conditions (pH 5.0, flow rate: 1.0 mL min(-1), T: 25 degrees C). Moreover, selectivity experiments were performed by using two interference proteins as myoglobin (Mb) and cytochrome c (Cyt-c) and the relative selectivity coefficients (k') for Hb/Mb and Hb/Cyt-c pairs were determined as 36.59 and 37.22, respectively.Öğe Pleurotus eryngii immobilized Amberlite XAD-16 as a abstract insert solid-phase biosorbent for preconcentrations of Cd2+ and Co2+ and their determination by ICP-OES (vol 99, pg 502, 2012)(Elsevier Science Bv, 2013) Ozdemir, Sadin; Okumus, Veysi; Kilinc, Ersin; Bilgetekin, Havin; Dundar, Abdurrahman; Ziyadanogullari, Berrin[Abstract Not Available]Öğe Pleurotus eryngii immobilized Amberlite XAD-16 as a solid-phase biosorbent for preconcentrations of Cd2+ and Co2+ and their determination by ICP-OES(Elsevier Science Bv, 2012) Ozdemir, Sadin; Okumus, Veysi; Kilinc, Ersin; Bilgetekin, Havin; Dundar, Abdurrahman; Ziyadanogullari, BerrinThis article reports a method that is used for the preconcentration and determination of Cd2+ and Co2+ in vegetables, using Pleurotus eryngii immobilized Amberlite XAD-16 as a solid-phase biosorbent. The concentrations of metals were determined by inductively coupled plasma-optical spectrometry (ICP-OES). Critical parameters, such as the pH of the solution, flow rate, the amount of biosorbent, type and volume of eluent, and the sample volume, that affect the solid-phase extraction (SPE) procedure were optimized. The optimum extraction conditions were determined as being a pH of 6.0 for Cd2+ and of 5.0 for Co2+; a sample flow rate of 2.0 mL min(-1); 200.0 mg of biosorbent; and 5.0 mL of 1.0 mol L-1 HCl as eluent. The capacities of the biosorbent for metal uptake were found to be 11.3 and 9.8 mg g(-1) for Cd2+ and Co2+ ions, respectively. Limit of quantitations (LOQs) were found to be 0.67 and 0.82 ng mL(-1), respectively, for Cd2+ and Co2+. The linear working curves were observed to be in the linear range from 1.0 to 50.0 ng mL(-1), and possessed high correlation coefficients. The use of the SPE method showed 50.7- and 35.7-fold improvements in the sensitivities of ICP-OES. The developed method was successfully applied to NCS ZC-73014 (a certified reference tea sample). Relative standard deviations (RSD) were lower than 5.0%. The Cd2+ and Co2+ concentrations in the different parts (leave, root, stem, and fruit) of purslane, onion, rocket, okra, and aubergine were determined after microwave digestion and solid-phase extraction by P. eryngii immobilized on Amberlite XAD-16. (C) 2012 Elsevier BM. All rights reserved.Öğe Preconcentration and determination of copper and cadmium ions with 1,6-bis(2-carboxy aldehyde phenoxy)butane functionalized Amberlite XAD-16 by flame atomic absorption spectrometry(Elsevier, 2011) Oral, Elif V.; Dolak, Ibrahim; Temel, Hamdi; Ziyadanogullari, BerrinA new chelating resin, covalently linked 1,6-bis(2-carboxy aldehyde phenoxy)butane with the Amberlite XAD-16 was synthesized and used for preconcentration of Cu(II) and Cd(II) prior to their determination by flame atomic absorption spectrometry (FAAS). It was characterized by elemental analyses and Fourier Transform Infrared Spectroscopy (FT-IR). Cu(II) and Cd(II) ions were quantitatively preconcentrated on minicolumn loaded with synthesised resin at pH 4.00 and 6.00, respectively. They were eluated with 5 mL of 0.5 mol L-1 HCl. Recoveries of Cu(II) and Cd(II) were found to be 100 +/- 2.15, 100 +/- 1.40(N= 5), the limits of detection of Cu(II) and Cd(II) in the determination by FAAS (3s, N= 20) were found to be 0.33 and 1.19 mu g L-1, respectively. The effect of foreign ions on the recovery has been investigated. The proposed method has been applied for the determination of Cu(II) and Cd(II) ions to the real samples collected from Tigris river water in Diyarbakir and Elazig cities in Turkey. Standard addition method and analysis of the certified reference material (NCS-DC 73350) was employed to check the accuracy of the method. (C) 2010 Elsevier B.V. All rights reserved.Öğe Separation, optimization, and quantification of cytokinins by a recently developed amide-embedded stationary phase(Taylor & Francis Inc, 2017) Aral, Hayriye; Hasimi, Duygu; Aral, Tarik; Levent, Abdulkadir; Ziyadanogullari, BerrinIn this study, some plant growth regulators known as cytokinins [kinetin (K), zeatin (Z), thidiazuron (TDZ), benzylaminopurine (BAP), and dimethylallylaminopurine (AAP)] were separated by HPLC using an amide-embedded mixed-mode stationary phase which was synthesized by Aral et al. in recent years. The effect of mobile phase content, mobile phase pH, buffer concentration, and temperature on separation process was studied. In addition, a quantitative determination of cytokinins from Salvia limbata extract was studied, and some validation parameters such as limit of detection (LOD), limit of quantification (LOQ), and relative standard deviation (RSD) were calculated as a range of 0.03-0.1, 0.1-0.26mg/L, and 0.03-0.08, respectively. [GRAPHICS] .Öğe Spectroscopic and electrochemical studies of transition metal complexes with N,N?-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane and structure effects on extractability of ligand towards some divalent cations(Springer Wien, 2007) Temel, Hamdi; Alp, Hueseyin; Ilhan, Salih; Ziyadanogullari, Berrin; Yilmaz, IsmailLa(III), Cu(II), Ni(II), and Zn(II) metal complexes with a novel quadridentate Schiff base derived from 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane and 2-aminothiophenol were synthesized and characterized by microanalytical data, elemental analysis, magnetic measurements, H-1 NMR, C-13 NMR, UV-Vis, IR, mass spectra, cyclic voltammetric and conductance measurements. The extractability of divalent cations was evaluated as a function of relationship between distribution ratio of the metal and pH or ligand concentration. The highest extraction percentage of Cu2+ and Ni2+ showed pH 7.0 and 6.4. It was concluded that the ligand can effectively be used in solvent extraction of copper(II) and nickel(II) from the aqueous phase to the organic phase.Öğe Spectroscopic and extraction studies of new transition metal complexes with N,N'-bis(2-aminothiophenol)-1, 4-bis(2-carboxaldehydephenoxy)butane(Taylor & Francis Ltd, 2008) Temel, Hamdi; Alp, Hueseyin; Ilhan, Salih; Ziyadanogullari, BerrinMetal complexes of La(III), Cu(II) and Ni(II) with a thio Schiff base derived from 1,4-bis(2-carboxaldehydephenoxy)butane and 2-aminothiophenol have been synthesized in absolute ethanol and characterized by microanalytical data, magnetic measurements, H-1 NMR, C-13 NMR, UV-visible, IR-spectra, mass spectra and conductance measurements. The extractability of divalent cations was evaluated as a function of relationship between distribution ratios of the metal and pH or ligand concentration. The highest extraction percentage of Cu+2 and Ni+2 were at pH 7.0 and 6.4, respectively. The ligand can effectively be used in solvent extraction of copper(II) and nickel(II) from aqueous phase to organic phase.Öğe 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, RecepA 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.
