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Öğe Amid-silika türevi polar faz yeni bir kolon dolgu materyalinin sentezi ve çeşitli polar analitlerin ayrılması(Muğla Üniversitesi, 2012-10) Aral, Tarık; Aral, Hayriye; Ziyadanoğulları, BerrinÖğe Amid-silika türevi yeni bir kolon dolgu materyalinin sentezi ve normal faz sıvı kromatografisi ile bitki büyüme düzenleyicilerinin ayrılması(Mustafa Kemal Üniversitesi, 2012-09) Aral, Tarık; Aral, Hayriye; Ziyadanoğulları, Berrin; Çelik, Kadir Serdar; Ziyadanoğulları, RecepÖğe Bazı kiral amit bileşiklerinin sentezi ve enantiyoseçici özelliklerinin araştırılması(Batman Üniversitesi, 2018-05) Aral, Tarık; Barış Cebe, Deniz; Aral, Hayriye; Sünkür, MuratÖğe Bir mixed-mode dolgu maddesi ile fenolik asitler ve flavonoidlerin ayrılması ve optimizasyonu(Batman Üniversitesi, 2018-05) Aral, Tarık; Aral, Hayriye; Sünkür, Murat; Barış Cebe, DenizÖğe C2-Symmetric chiral diamine ligands for enantiomeric recognition of amino acid esters and mandelic acid by proton nmr titration method(TÜBİTAK, 2013-07-08) Aral, Hayriye; Aral, Tarık; Çolak, Mehmet; Ziyadanoğulları, Berrin; Ziyadanoğulları, RecepTwo novel C2 -symmetric chiral diamines containing α-phenylethyl and α-(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 1H NMR titration method. These ligands exhibited strong complexation (with Kf up to 2481 M-1) and good enantioselectivity (up to KL /KD = 4.08) towards the mandelic acid enantiomers. The results show that simple structured and easily accessible acyclic C2 -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 Development of a novel amide silica stationary phase for the reversed phase HPLC separation of different classes of phytohormones(Journals & Books, 2013-05-14) Aral, Tarık; Aral, Hayriye; Ziyadanoğulları, Berrin; Ziyadanoğulları, RecepA novel amide-bonded silica stationary phase was prepared starting fromN-Boc-phenylalanine, cyclo-hexylamine and spherical silica gel (4mm, 60 Å). The amide ligand was synthesised with high yield. Theresulting amide bonded stationary phase was characterised by SEM, IR and elemental analysis. Theresulting selector bearing a polar amide group is used for the reversed-phase chromatography separationof different classes of thirteen phytohormones (plant hormones). The chromatographic behaviours ofthese analytes on the amide-silica stationary phase were compared with those of RP-C18 column undersame conditions. The effects of different separation conditions, such as mobile phase, pH value,flow rateand temperature, on the separation and retention behaviours of the 13 phytohormones in this systemwere studied. The optimum separation was achieved using reversed-phase HPLC gradient elution with anaqueous mobile phase containing pH¼6.85 potassium phosphate buffer (20 mM) and acetonitrile with a221C column temperature. Under these experimental conditions, the 12 phytohormones could beseparated and detected at 230 or 270 nm within 26 minÖğe Development of a novel amide-silica stationary phase for the reversed-phase HPLC separation of different classes of phytohormones(Elsevier, 2013-11) Aral, Hayriye; Aral, Tarık; Ziyadanoğulları, Berrin; Ziyadanoğulları, RecepA novel amide-bonded silica stationary phase was prepared starting from N-Boc-phenylalanine, cyclohexylamine and spherical silica gel (4 μm, 60 Å). 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 C column temperature. Under these experimental conditions, the 12 phytohormones could be separated and detected at 230 or 270 nm within 26 min.Öğe Enantiomeric recognition of 1-arylethylamins usin c2 symmetrical chiral tetraamdes(IKSAD Publishing House, 2018-04) Aral, Tarık; Sünkür, Murat; Barış Cebe, Deniz; Aral, HayriyeÖğe HILIC separation and optimization of B vitamins usıng the Ile-PBA-Mix, a mıxed-mode stationary phase(Hitit Üniversitesi, 2017-09) Aral, Tarık; Aral, Hayriye; Altındağ, Ramazan; Çelik, Kadir SerdarÖğe HPLC separation of different groups of small polar compounds on a novel amide-embedded stationary phase(Elsevier, 2014-05-10) Aral, Hayriye; Aral, Tarık; Çelik, Kadir Serdar; Ziyadanoğulları, Berrin; Ziyadanoğulları, 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 Kiral tetraamid jelatörleri(Erzurum Atatürk Üniversitesi, 2018-03) Aral, Tarık; Aral, Hayriye; Sünkür, Murat; Barış Cebe, DenizÖğe Optimised HILIC separation and method validation of b vitamins using a mixed-mode stationary phase(Fırat Üniversitesi, 2017-10) Aral, Tarık; Aral, Hayriye; Çelik, Kadir Serdar; Altındağ, RamazanÖğe Polar HPLC sabit fazlarında son gelişmeler: Mixed-Mode kromatografi(Hitit Üniversitesi, 2017-09) Aral, Tarık; Aral, Hayriye; Altındağ, Ramazan; Çelik, Kadir SerdarSabit faz kromatografinin ana unsurudur. Özellikle HPLC’de sabit fazın önemi çok büyüktür. Ayırma mekanizması, ayırma selektivitesi ve kolon etkinliği dolgu maddesinin yapısına bağlıdır. Geleneksel sabit fazlar (NP ve RP)da ayırma mekanizması tek bir etkileşime dayanırken mixed model sabit fazlarda bir çok ayırma mekanizması geçerlidir. Polar dolgu fazları yapılarına göre üç gruba ayrılır: Polar gömülü, polar HILIC ve polar mixed-mode1. Bir dolgu maddesinin mixed-mode olarak nitelendirilmesi için analitlerle en az iki farklı etkileşim göstermelidir. Geleneksel dolgu maddeleri ile kıyaslandığında, bu farklı etkileşim türleri büyük avantaj sağlar: yüksek ayırma selektivitesi, yüksek bağlanma kapasitesi ve yüksek kolon etkinliği (teorik tabaka sayısı) v.b. 2. Son birkaç yılda mixed-mode sabit fazlar üzerine çalışmalar ve bu alana olan ilgi hızla artmaktadır. Çok sayıda mixed-mode sabit faz hazırlanmış olup polardan apolara pek çok analit grubunun ayrılmasında tek bir kolon başarı ile kullanılmıştır 3. Geleneksel ters faz kolonlar düşük ve orta polarlıktaki bileşiklerin ayrılmasında başarı ile kullanılırken mixed-mode kolonlar düşük polariteden çok yüksek polariteye sahip çok farklı analit gruplarının ayrılmasında da kullanılabilmektedir. Böylece bir mixed-mode kolon hem ters faz hem HILIC hem normal faz kolon görevi görmüş olur1. Grubumuz 2012 yılından beri mixed-mode sabit fazlar üzerine çalışmakta, bu alanın gelişimine önemli katkılar sağlamaktadır [4-5]. Genellikle doğal amino asit bileşiklerinden yola çıkılarak geliştirdiğimiz farklı yapıdaki mixed-mode sabit fazlar ile pek çok polar-apolar bileşik sınıfı başarı ile ayrılmış olup, hazırlanan kolonlar ticari kolonlar ile yarışacak, ticari kolonlara alternatif olabilecek niteliktedir. Bu sunum kapsamında, öncelikli olarak kendi çalışmalarımızdan oluşan son yıllarda mixedmode kromatografi alanındaki gelişmelerin kısa bir özeti sunulacaktır.Öğe Potansiyel ilaç taşıyıcı sistem olarak tetraamid jelatörler(Erzurum Atatürk Üniversitesi, 2018-03) Aral, Tarık; Aral, Hayriye; Barış Cebe, Deniz; Sünkür, MuratÖğe Preparation of a novel ionic hybrid stationary phase by non-covalent functionalization of single-walled carbon nanotubes with amino-derivatized silica gel for fast HPLC separation of aromatic compounds(Elsevier, 2016-03) Aral, Hayriye; Çelik, Kadir Serdar; Aral, Tarık; Topal, GiraySingle-walled carbon nanotubes (SWCNTs) were immobilized on spherical silica gel with a 4-μm average particle size and a 60-Å average pore size. The amino-derivatized silica gel was non-covalently coated with carboxylated SWCNTs to preserve the structure of the nanotubes and their physico-chemical properties. The novel ionic hybrid stationary phase was characterized by scanning electron microscopy (SEM), infra-red (IR) spectroscopy and elemental analysis, and then, it was used to fill an empty 150×4.6 mm 2 high-performance liquid chromatography (HPLC) column. Chromatographic parameters, such as the theoretical plate number, retention factor and peak asymmetry factor, and analytical parameters, such as the limit of detection (LOD), limit of quantification (LOQ), linear range, calibration equation, and R 2 value, and quantitative analysis parameters were calculated for all of the analytes. Using different mobile phases, five different classes of aromatic hydrocarbons were separated in a very short analysis time of 4-8 min. Furthermore, a high theoretical plate number (up to 25000) and an excellent peak asymmetry factor (1.0) were obtained. The results showed that the surface of the SWNTs had very strong interactions with aromatic groups, therefore providing high selectivity for the separation of different classes of aromatic compounds. This study indicates that SWCNTs enable the extension of the application range of the newly prepared stationary phases for the fast separation of aromatic compounds by HPLC.Öğe Separation, optimization, and quantification of cytokinins by a recently developed amide-embedded stationary phase(Taylor & Francis, 2017-07-06) Aral, Hayriye; Haşimi, Duygu; Aral, Tarık; Levent, Abdulkadir; Ziyadanoğulları, 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, 0.1–0.26 mg/L, and 0.03–0.08, respectively.Öğe Syntheses of c2 symmetrical chiral tetraamides and their enantiomeric recognition ablity towards amino acide esthers(EJONS International Congress on Mathematics, Enginerimg and Natural Science, 2018-04) Aral, Tarık; Sünkür, Murat; Barış Cebe, Deniz; Aral, HayriyeÖğe 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, 2015-01) Aral, Tarık; Aral, Hayriye; Ziyadanoğulları, Berrin; Ziyadanoğulları, RecepA novel mixed-mode stationary phase was synthesised starting from N-Boc-glutamine, aniline and spherical silica gel (4 μm, 60 Å). 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 °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 °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 °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 °C column temperature and seven phenolic compounds could be separated and detected at 230 nm within 16 min.Öğe Synthesis, characterization and application of a novel multifunctional stationary phase for hydrophilic interaction/reversed phase mixed-mode chromatography(Talanta, 2017-11-1) Aral, Tarık; Aral, Hayriye; Çelik, Kadir Serdar; Altındağ, RamazanA novel multifunctional stationary phase based on silica gel was synthesised starting from L- isoleucine and 4-phenylbutylamine and evaluated as a hydrophilic interaction/reversed-phase mixed-mode stationary phase for high-performance liquid chromatography (HPLC). The prepared stationary phase was characterized by elemental analysis, infrared spectroscopy (IR), scanning electron microscopy (SEM), Brunauer, Emmett and Teller (BET) and solid-state 13C nuclear magnetic resonance (NMR). The mechanisms involved in the chromatographic separation are multi-interaction, including hydrophobic, π-π, hydrogen-bonding, dipole-dipole and ion-dipole interactions. Based on these interactions, successful separation could be achieved among several aromatic compounds having different polarities under both hydrophilic interaction liquid chromatography (HILIC) and reversed phase (RP) condition. Nucleotides/nucleosides were separated in the HILIC mode. The effects of different separation conditions, such as pH value, mobile-phase content, column temperature, buffer concentration and flow rate, on the separation of nucleotides/nucleosides in HILIC mode were investigated. The seven nucleotides/nucleosides were separated within 22 min, while six of them were separated within 10 min by isocratic elution. To determine the influence of the new multifunctional stationary phase under the RP condition, a number of moderately and weakly polar and nonpolar compounds, such as 10 substituted anilines and eight substituted phenols were separated successfully under the RP condition within 14 and 15 min, respectively. Additionally, nine mixtures of polar/nonpolar test compounds were simultaneously separated within 19 min, while seven of them were separated within 12 min, under HILIC/RP mixed-mode conditions. Chromatographic parameters, such as the retention factor and peak asymmetry factor, were calculated for all of the analytes, while the theoretical plate number was calculated for analytes separated by isocratic elution. Compared to traditional C18 and commercial HILIC columns, the new stationary phase exhibited both HILIC and RPLC performance, and the scope of analyte separation was thus enlarged.Öğe Synthesis, characterization and application of a novel multifunctional stationary phase for hydrophilic ınteraction/reversed phase mixed-mode chromatography(2017-10) Aral, Tarık; Çelik, Kadir Serdar; Aral, Hayriye; Altındağ, Ramazan
