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Öğe Akış enjeksiyon-katı faz ekstraksiyon sistemi ile bazı metal iyonlarının tayin edilmesi(Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2008-06-26) Durmaz, Fatih; Kara, HüseyinBu çalışmada, hümik asitlerin immobilizasyonu sonucunda çözünürsüzleştirilmiş hümik asitin (ImHA) katı formu sabit faz olarak kullanılmıştır. Birleştirilmiş Akış Enjeksiyon-Katı Faz Ekstraksiyon ve Kromatoğrafik ayırma sistemleri için (6 girişli 2 pozisyonlu) iki adet valf sistemi ve yeni bağlantılarla HPLC cihazı modifiye edilmiş, Cu(II), Ni(II), Co(II) metal iyonlarını tutma kapasitesi ve özellikleri incelenmiştir. Metallerin karışım halinde bulunmadığı durumlarda Akış Enjeksiyon sistemleri çok verimli olduğu görülmüştür. Ön kolon (Sodyum dodekilsülfat) ve post kolon türevlendirme (PAR) sistemi ile Cu(II), Ni(II), Co(II), Fe(III), Pb(II), Zn(II), Cd(II) metal iyonları ayrı ayrı ve karışım halinde C18 kolon üzerinde ayırılmış ve 530 nm dalga boyunda UV dedektörde tayin edilmiştir. Sonuç olarak FIA-SPE birleştirilmiş analiz sistemlerinde sabit faz olarak çözünürsüzleştirilmiş hümik asidin kullanımının verimli olduğu ve bazı metal iyonlarının ayırılması için C18 kolonuyla birlikte ön deriştirici kolon olarak kullanılabileceği görülmüştür. Metal iyonlarının tutulma ve ayrılma özelliklerinin belirlenmesinde, geliştirilen bu FIA-SPE birleştirilmiş sistemleri; uygulanabilir, tekrarlanabilir, verimli ve etkili online deriştirme sistemi olduğu tespit edilmiştir.Öğe Alpha-novel Determination Method of Cu(II) Ions on the Immobilized Humic Acid by SPE-FIA Hyphenated Technique(Elsevier Science Bv, 2010) Durmaz, Fatih; Kara, HüseyinThe aim of this study was to optimize the integrated SPE-FIA (Solid phase extraction-flow-injection analysis) hyphenated technique for determination of trace level of Cu(II) ions where flow-injection sample processing was used. Firstly, Humic acid (HA) was immobilized onto aminopropyl silica (APS). Then, the material was filled into the column using slurry packing procedure. The prepared column was assembled to HPLC using two valves system for SPE-FIA analysis and used for the removal of Cu(II) ions from aqueous solution. The analysis of Cu (II) ions was realized by both SPE and FIA techniques on modified HPLC system as online. In SPE system, Cu(II) ions were preconcentrated on micro column loaded with immobilized humic acid (ImHA). EDTA (pH = 8) solution was used for the elution of Cu(II) ions sorbed by ImHA. The sorption characteristics of Cu(II)-immobilized humic acid system were investigated at different Cu(II) concentrations, and output was observed by a UV detector. The developed method was applied for online metal ion determination in samples, especially Cu (II) and obtained results compared with atomic absorption spectrophotometer (AAS) results. Sorption characteristics were evaluated by using Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) adsorption isotherms, as well as by Scatchard plot analysis.Öğe Bovista plumbea F_’ers.'nın Yağ Asiti içeriklerinin Incelenmesi(2017) Durmaz, Fatih; Aktaş, Sinan; Sezer, Ela Nur ŞimşekBu çalışmada halk arasında puf mantarı olarak bilinen ve çeşitli bölgelerden toplanan Bovista plumbea Pers. türünün yağ asit kompozisyonları incelenmiştir. İncelenen türe ait yağ asit kompozisyonlarında oran olarak en fazla heneikosanoik asit (C21:0), eikosenoik asit (C20:1 ), behenik asit (C22:0), vaksenik asit (C18:1 ), linoleik asit (C18:2) ve linolenik asit (C18:3) izomerleri tespit edilmiştir.Öğe Bovista plumbea Pers.'nın yağ asit içeriklerinin incelenmesi(Selçuk Üniversitesi, Mantarcılık Uygulama ve Araştırma Merkezi Müdürlüğü, 2017) Durmaz, Fatih; Aktaş, Sinan; Sezer, Ela Nur Şimşek SezerBu çalışmada halk arasında puf mantarı olarak bilinen ve çeşitli bölgelerden toplanan Bovista plumbea Pers. türünün yağ asit kompozisyonları incelenmiştir. İncelenen türe ait yağ asit kompozisyonlarında oran olarak en fazla heneikosanoik asit (C21:0), eikosenoik asit (C20:1), behenik asit (C22:0), vaksenik asit (C18:1), linoleik asit (C18:2) ve linolenik asit (C18:3) izomerleri tespit edilmiştir.Öğe Copper sorption efficiency of p-tetranitrocalix[4]arene based high performance liquid chromatographic column(DESALINATION PUBL, 2016) Durmaz, Fatih; Memon, Fakhar N.; Memon, Shahabuddin; Memon, Ayaz A.; Memon, Naeem A.; Kara, HuseyinPresent study deals with the sorption characteristics of p-tetranitrocalix[4]arene (3) appended silica-based high-performance liquid chromatographic (HPLC) column utilized for preconcentration, determination, and purification of Cu2+ from water. The sorption characteristics of the HPLC column were investigated for Cu2+ in column agreement. The experiments were performed in five steps that were monitored using UV-visible diode-array detector. However, all the HPLC experimental results were reconfirmed by using atomic absorption spectrophotometer. The effect of concentration on the sorption efficiency of the column was evaluated for Cu2+ and data obtained was investigated using Langmuir and Freundlich sorption isotherms. The value of coefficient of determination (R-2), i.e. 0.99, suggested that the Freundlich sorption isotherm was found to be the best fit model for Cu2+. The developed method was validated for system efficiency, accuracy, and precision, while the data obtained revealed that the developed column could be applied for the sorption of Cu2+ with adequate efficiency and repeatability.Öğe Determination of free radical on polycrystal of 4,4 '-bis(chloroacetyl)diphenylether: An ESR study(ELSEVIER SCIENCE BV, 2013) Ceylan, Yusuf; Usta, Ayhan; Usta, Keziban; Durmaz, Fatih; Coskun, Ahmet4,4'-Bis(chloroacetyl)diphenylether was synthesized and its polycrystal form was produced. This polycrystal sample was irradiated by gamma rays (Co-60) for 72 h. The ESR method was used to observe formation of free radical on the sample. ESR signal was not recorded from the non-irradiated sample, but the irradiated polycrystal sample exhibited complex ESR spectra. The measurements were carried out in the temperature range of 120-450 K. It was observed that the shape of the spectrum was dependent on the temperature. Two identical radicals were determined on the irradiated sample. Respectively, the spin density, hyperfine, and g values were found to be rho(Ha) = 0.53, rho(Hb) = 0.23, a(Cl) = 1.263 mT, a(Ha) = 1.486 mT, a(Hb) = 0.637 mT, and g(1) = 2.0115 for the Radical rho(Hx) = 0.22, rho(Hy) = 0.14, a(Cl) = 0.905 mT, a(Hx) = 0.615 mT, a(Hy) = 0.391 mT, and g(2) = 2.0383 for the Radical II. (C) 2013 Elsevier B.V. All rights reserved.Öğe Excess molar volumes, viscosity, refractive index, and Gibbs energy of activation of binary biodiesel plus benzene, and biodiesel plus toluene mixtures at 298.15 and 303.15 K(MAIK NAUKA/INTERPERIODICA/SPRINGER, 2008) Vural, Ufuk Sancar; Durmaz, Fatih; Koçyiğit, Özcan; Koçyiğit, Hasan; Muradoğlu, V.; Akın, BerilExcess molar volumes (VE ), viscosities, refractive index, and Gibbs energies were evaluated for binary biodiesel + benzene and toluene mixtures at 298.15 and 303.15 K. The excess molar volumes VE were determined from density, while the excess Gibbs free energy of activation G*Ewas calculated from viscosity deviation Delta eta. The excess molar volume (V E), viscosity deviation (Delta eta), and excess Gibbs energy of activation (G*E) were fitted to the Redlich-Kister polynomial equation to derive binary coefficients and estimate the standard deviations between the experimental data and calculation results. All mixtures showed positive V E values obviously caused by increased physical interactions between biodiesel and the organic solvents.Öğe Oxidation on the Stability of Canola Oil Blended with Stinging Nettle Oil at Frying Temperature(TAYLOR & FRANCIS INC, 2015) Durmaz, Fatih; Talpur, M. YounisThe present study was carried out to investigate changes in fatty acids composition and their ratio by mixing of canola oil (CLO) with cold pressed stinging nettle oil (SNO) during heating at 180 degrees C for 10 h, and analyzed by gas chromatography-mass spectrometry. The blended oils were prepared by gravimetrically mixing of CLO and SNO at various ratios of 60:40 and 40:60 w/w, respectively. Trans fatty acid in fresh CLO and SNO of 1.1 and 0.05%, whereas fresh blended oils of CLO:SNO (40:60, 60:40 w/w) contained 0.44, 0.91% and heated oils of CLO, SNO and CLO: SNO (40:60, 60:40 w/w) were found from 1.35 -2.49, 0.06 -0.09, and 0.46 -0.51, 1.02 -1.27%, correspondingly. The linolenic fatty acid is more prone to oxidation in heated oils and their percentage in fresh CLO, SNO and blended (40:60, 60:40) CLO:SNO samples of 10.58, 0.00, and 3.94, 6.64%, respectively. The linolenic acid was decreased from 10.27 -6.54, 0.00, and 3.93 -3.79%, 6.47 -5.68% in heated CLO, SNO and CLO:SNO (40:60, 60:40 w/w) oils, respectively. The oxidation parameters were also analyzed such as free fatty acids, peroxide value, iodine value, conjugated diene and triene using standard methods. The best results of free fatty acids, peroxide value, iodine value, conjugated diene and triene were obtained in blended CLO:SNO (40:60 w/w) oil at 0.31%, 0.63 meqO(2)/Kg, 0.79 g/100 g, 60 and 31.36% during 10 h. The obtained results show that mixing of CLO with SNO increased the stability against oxidation and consequently enhanced the worth of CLO during heating/frying route.Öğe Preconcentration and Determination of Toxic Metals by A New Calix[4]arene Bonded HPLC Column(SPRINGER HEIDELBERG, 2013) Durmaz, Fatih; Memon, Fakhar N.; Memon, Naeem A.; Memon, Sibghatullah; Memon, Shahabuddin; Kara, HuseyinThe present study deals with the preconcentration and determination of toxic metal ions using p-tetranitrocalix[4]arene (3) appended silica-based new HPLC column. The synthesized material was characterized using Fourier transform infrared and scanning electron microscopy techniques. The sorption characteristics of the HPLC column were investigated for three toxic metals (Cd2+, Hg2+ and Pb2+) in column agreement. The experiments were performed in five steps that were monitored using a UV-visible diode-array detector. However, all the HPLC experimental results were reconfirmed by using atomic absorption spectrophotometer. The effect of concentration on the sorption efficiency of the column was evaluated for all the three metals and the data obtained were investigated using Langmuir, Freundlich and Dubinin-Redushkevich (D-R) sorption isotherms. The value of coefficient of determination (R (2)), i.e. 0.99, suggested that the Freundlich sorption isotherm was found to be the best-fit model for all the three toxic metal ions, whereas, mean free energy was calculated from the D-R isotherm as 5.3, 5.7, and 5.8 kJ/mol for Pb2+, Cd2+, and Hg2+, respectively; suggesting that physical electrostatic force is involved in the sorption process. The developed method was validated for system efficiency, accuracy, and precision.Öğe Removal and Preconcentration of Cobalt Ions from Aqueous Media Using ImHA Packed Column by On-Line SPE System(SPRINGER INTERNATIONAL PUBLISHING AG, 2012) Ayyildiz, H. Filiz; Topkafa, Mustafa; Arslan, FatmaNur; Durmaz, Fatih; Kucukkolbasi, Semahat; Tarhan, Ismail; Kara, HuseyinThis work assesses the use of immobilized humic acid (ImHA) onto aminopropyl silica (APS) as a sorbent for the removal and preconcentration of trace amounts of cobalt ions by on-line solid phase extraction (SPE) technique in the column system prepared in our laboratory. Different parameters, such as the effect of the pH, concentration, and flow rate, were studied and throughput was observed by a UV detector. All SPE steps were monitored by breakthrough curves used to visualize distribution of cobalt concentration between mobile and solid phase. The solutions collected from stripping steps were analyzed in atomic absorption spectrometer (AAS) and the amount of sorbed ions was calculated. Sorption characteristics were evaluated by using common adsorption isotherms and Scatchard plot analysis. From the obtained results, it was seen that sorption mechanism of cobalt ions were fitted to Langmuir model on a large scale and thought to be localized. Mean free energy (E = 40.82 kJ mol(-1)) calculated from D-R isotherm showed that chemical interactions are more effective than physical interactions. This investigation reveals a new, simple, environmentally friendly, and cost-effective method for removal and preconcentration of cobalt ions from aqueous solutions by a new aminopropyl silica-immobilized humic acid material.Öğe Role of Different Bleaching Earths for Sunflower Oil in a Pilot Plant Bleaching System(DE GRUYTER OPEN LTD, 2013) Topkafa, Mustafa; Ayyildiz, H. Filiz; Arslan, Fatma Nur; Kucukkolbasi, Semahat; Durmaz, Fatih; Sen, Seyit; Kara, HuseyinThe purpose of present study is to investigate the efficiency of different kinds of Turkish commercial bleaching earth materials for changes in different colour pigment concentrations in neutralized sunflower oils. The bleaching experiments were performed in a pilot system under at stable vacuum (50 mmHg) and temperature (100 degrees C) for 30 min. By examining the changes in chlorophyll, beta-carotene and red colour, bleaching process parameters such as type and dosage of the bleaching material were optimised. The sorption characteristics of colour pigments were evaluated using common adsorption isotherms and Scatchard plot analysis. Ads-3 acid-activated earth material at 1% (w/w) per samples was found to be the most appropriate sorbent and the amount of sorbed pigments was calculated as 1.01x10(-4)mmol/g ads. for chlorophyll, 1.15x10(-3)mmol/g ads. for carotene and 1.70 red on Lovibond colour scale. The procedure indicated that this system can be easily adapted to the actual oil refining systems.Öğe Simultaneous determination of some basic dyes using p-tetranitrocalix[4]arene-appended silica-based HPLC column(ROYAL SOC CHEMISTRY, 2014) Memon, Shahabuddin; Memon, Fakhar N.; Durmaz, Fatih; Memon, Naeem A.; Memon, Ayaz A.; Kara, HuseyinThis study focuses on the synthesis, characterization and application of p-tetranitrocalix[4]arene-appended silica-based material as a stationary phase in high-performance liquid chromatography for the simultaneous separation of some basic dyes such as methyl violet, methyl green and methylene blue. The effect of the pH of mobile phase on the retention, separation and selectivity of these compounds was investigated. The method was validated for system efficiency, linearity, accuracy, precision, limit of detection and quantification. The limits of detection were 0.1, 0.5 and 0.3 mg L-1; whereas, the limits of quantification were observed to be 1, 1.2 and 0.9 mg L-1 for methyl violet, methyl green and methylene blue, respectively. The separation efficiency of the p-tetranitrocalix[4]arene-appended silica-based column was also compared to that of the octadecylsilane column.Öğe Transport of Amino Acids Through Charged Cation-exchange Membrane(INST ORGANIC CHEM AND BIOCHEM, 2001) Kara, H; Yazicigil, Zafer; Durmaz, Fatih; Ersoz, MustafaThe sorption and transport of amino acids such as glycine, L-valine and L-leucine through charged polysulfone membranes was investigated as a function of pH lower than 5.6 under three different interfacial conditions. The sorption was characterized by the Langmuir and the Freundlich equations. The highest permeability was obtained if the initial pH on the amino acid source side was 5.6 and that on the opposite side 2.5, the intermediate permeability was obtained if the initial pH on both sides was 2.5, and the smallest permeability was obtained if the initial pH on the amino acid side was 5.6. The obtained results are explained in terms of the interfacial transport based on the chemical reaction (protonation and ion exchange).Öğe The Use of Calixarene Nanofibers as an HPLC Column Filler(IEEE, 2017) Ali, S. S.; Şen, Nejdet; Durmaz, Fatih; Özcan, Fatih; Ertul, ŞerefThe third generation molecule of supramolecule chemistry, the calixarenes, is superior to the first and second generation molecules, Tac Ethers and Cyclodextrins, due to their ability to be obtained in greater quantities in higher purity and easier to function. The fact that the calixarenne compounds are important in the host-guest chemistry, and that they are ring structures, can carry molecules, anions or cations with advantages such as the absence of molecules [1-3]. In this work, the p-tert-butylcalix[4] arene diester compound was reacted with benzylamine. The structure of the p-tert-butylcalix[4] arene benzylamide molecule obtained as a result of the reaction was elucidated by H-1-NMR and then electrospun nanofibers were used as an HPLC column filler.Öğe Yenilebilir bir tür olan Lycoperdon utriformis Bull.’in yağ asit kompozisyonlarının gaz kromatoğrafisi (GC)’de tayin edilmesi(Selçuk Üniversitesi, Mantarcılık Uygulama ve Araştırma Merkezi Müdürlüğü, 2018-04) Durmaz, Fatih; Sezer, Ela Nur Şimşek; Aktaş, SinanAfyon, Ladik (Samsun) ve Manavgat (Antalya) bölgelerinden toplanan mantar örnekleri kurutulup, teşhisleri yapıldıktan sonra birleştirilerek tek bir numune halinde sürekli ekstraksiyon yöntemiyle elde edilen ekstraktının esterleşme reaksiyonları yapılarak yağ asit kompozisyonları tayin edilmiştir. Lycoperdon utriformis Bull. türünün tayin edilen yağ asiti kompozisyonları kromatoğram ve tablo halinde verilmiştir. Elde edilen sonuçlara göre, Lycoperdon utriformis’te oleik asit (%7.75), stearik asit (%7.63) ve ?-linolenik asit (%6) yüzdelerinin en yüksek düzeylerde olduğu belirlenmiştir.Öğe Yenilebilir bir tür olan Lycoperdon utriformis Bull.’in yağ asit kompozisyonlarının gaz kromatoğrafisi (GC)’de tayin edilmesi(2018) Durmaz, Fatih; Sezer, Ela Nur Şimşek; Aktaş, SinanAfyon, Ladik (Samsun) ve Manavgat (Antalya) bölgelerinden toplanan mantar örnekleri kurutulup, teşhisleri yapıldıktan sonra birleştirilerek tek bir numune halinde sürekli ekstraksiyon yöntemiyle elde edilen ekstraktının esterleşme reaksiyonları yapılarak yağ asit kompozisyonları tayin edilmiştir. Lycoperdon utriformis Bull. türünün tayin edilen yağ asiti kompozisyonları kromatoğram ve tablo halinde verilmiştir. Elde edilen sonuçlara göre, Lycoperdon utriformis’te oleik asit (%7.75), stearik asit (%7.63) ve ?-linolenik asit (%6) yüzdelerinin en yüksek düzeylerde olduğu belirlenmiştir.
