Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- 1 (98)
- 2 (83)
- Synthesis (61)
- Adsorption (56)
- Antimicrobial activity (47)
-
- 3 (45)
- Phthalocyanine (35)
- Antibacterial activity (31)
- Molecular docking (30)
- Cytotoxicity (28)
- Preconcentration (26)
- Cyclic voltammetry (25)
- Palladium (25)
- Voltammetry (25)
- Schiff base (24)
- Spectrophotometry (24)
- Copper (23)
- Fluorescence (23)
- Lamiaceae (22)
- DFT (20)
- Kinetics (20)
- Antioxidant activity (19)
- Antioxidant (18)
- Cadmium (18)
- Chitosan (18)
- Nanoparticles (18)
- Photocatalysis (18)
- Antimicrobial (17)
- Catalyst (16)
- Electrospinning (16)
- Publication Year
Articles 451 - 480 of 2806
Full-Text Articles in Entire DC Network
First Determination Of Some Phenolic Compounds And Antimicrobial Activities Ofgeranium Ibericum Subsp. Jubatum: A Plant Endemic To Turkey, Mehmet Emi̇n Şeker, Emri̇ye Ay, Ayça Aktaş Karaçeli̇k, Rena Hüseyi̇noğlu, Derya Efe
First Determination Of Some Phenolic Compounds And Antimicrobial Activities Ofgeranium Ibericum Subsp. Jubatum: A Plant Endemic To Turkey, Mehmet Emi̇n Şeker, Emri̇ye Ay, Ayça Aktaş Karaçeli̇k, Rena Hüseyi̇noğlu, Derya Efe
Turkish Journal of Chemistry
This paper includes the results of the first study about the phenolic characteristics and antimicrobial analyses of Geranium İbericum subsp. jubatum species found in Turkey. In the present work, the phenolic contents of different parts of the G. İbericum (flower, root, leaf ) were determined with high-performance liquid chromatography (HPLC)-DAD (diode-array detector) and liquid chromatography (LC)-MS/MS (mass spectrometry). The following phenolic compounds were investigated: catechin, protocatechuic acid, gallic acid, ellagic acid, chlorogenic acid, 4-hydroxybenzaldehyde, p-coumaric acid, rutin, naringenin, kaempferol. Based on the results obtained, the roots and flowers of the plant are found to be very rich in ellagic acid …
Comparison Of Clinically Approved Molecules On Sars-Cov-2 Drug Target Proteins: A Molecular Docking Study, Hasan Çubuk, Mehmet Özbi̇l
Comparison Of Clinically Approved Molecules On Sars-Cov-2 Drug Target Proteins: A Molecular Docking Study, Hasan Çubuk, Mehmet Özbi̇l
Turkish Journal of Chemistry
The new type of coronavirus, SARS-CoV-2 has affected more than 22.6 million people worldwide. Since the first day the virus was spotted in Wuhan, China, numerous drug design studies have been conducted all over the globe. Most of these studies target the receptor-binding domain of spike protein of SARS-CoV-2, which is known to bind to the human ACE2 receptor and SARS-CoV-2 main protease, vital for the virus' replication. However, there might be a third target, human furin protease, which cleaves the virus' S1-S2 domains playing an active role in its entry into the host cell. In this study, we docked …
In Situ Preparation Of Hetero-Polymers/Clay Nanocomposites By Cuaac Click Chemistry, Mehmet Ati̇lla Taşdelen, Çağatay Altinkök
In Situ Preparation Of Hetero-Polymers/Clay Nanocomposites By Cuaac Click Chemistry, Mehmet Ati̇lla Taşdelen, Çağatay Altinkök
Turkish Journal of Chemistry
A series of polymer/clay nanocomposites containing mechanistically two different polymers, poly(ethylene glycol) (PEG) and poly(epsilon caprolactone) (PCL), were prepared by simultaneous copper(I)-catalyzed alkyne-azide cycloaddition click reactions. Both clickable polymers, PEG-Alkyne and PCL-Alkyne, were simultaneously clicked on to azide-functional montmorillonite (MMT-N3) nanoclay to get corresponding PEG-PCL/MMT nanocomposites. The chemical structures of the resulting nanocomposites were verified by following azide and silicone-oxygen bands using FT-IR and characteristic bands of PEG and PCL segments using 1H-NMR spectroscopy. The combined XRD and TEM analysis confirmed that all PEG-PCL/MMT nanocomposites had partially exfoliated/ intercalated morphologies. In addition, the increase of MMT-N3 loading not only improved …
Spectrophotometric Analysis Of Stability Of Gold Nanoparticles During Catalytic Reduction Of 4-Nitrophenol, Farhat Saira, Samia Saleemi, Humaira Razzaq, Rumana Qureshi
Spectrophotometric Analysis Of Stability Of Gold Nanoparticles During Catalytic Reduction Of 4-Nitrophenol, Farhat Saira, Samia Saleemi, Humaira Razzaq, Rumana Qureshi
Turkish Journal of Chemistry
Spectrophotometric monitoring of 4-nitrophenol (4-NP) reduction by sodium borohydride (NaBH4) using gold nanoparticles (GNPs) as a catalyst has been extensively studied, but the stability of GNPs in terms of change in the surface plasmon resonance (SPR) at different temperatures has not been explored. In the present investigation, our aim was to evaluate the SPR stability of GNPs as a catalyst during the reduction of 4-NP at different elevated temperatures (i.e. 30-60 °C) and sodium borohydride concentrations. Sensitivity of this degradation process toward concentration of GNPs at a range of temperatures is also evaluated. The spectrophotometric results reveal that up to …
Synthesis And Characterization Of Novel 4-Benzyloxyphenyl 4-[4-(N-Dodecyloxy)Benzoyloxy]Benzoate Liquid Crystal, Emi̇ne Balkanli, Fati̇h Çakar, Hale Ocak, Özlem Cankurtaran, Belkiz Bi̇lgi̇n Eran
Synthesis And Characterization Of Novel 4-Benzyloxyphenyl 4-[4-(N-Dodecyloxy)Benzoyloxy]Benzoate Liquid Crystal, Emi̇ne Balkanli, Fati̇h Çakar, Hale Ocak, Özlem Cankurtaran, Belkiz Bi̇lgi̇n Eran
Turkish Journal of Chemistry
Liquid crystal (LC) compound 4-Benzyloxyphenyl 4-[4-(n-dodecyloxy)benzoyloxy]benzoate (BDBB) was prepared and characterized. Inverse gas chromatography (IGC) was to be a beneficial analysis method for the research of thermodynamic characteristics of the new LC. Acetate and alcohol isomers were used to examine LC selectivity via the IGC technique at temperatures between 333.2 K and 483.2 K. The retention diagrams of n-heptane, n-octane, n-nonane, n-decane, undecane, dodecane, tridecane, n-butyl acetate, isobutyl acetate, ethyl acetate, n-propylbenzene, isopropylbenzene, ethylbenzene, chlorobenzene, and toluene on BDBB were plotted with temperatures of 483.2?493.2 K. Flory?Huggins interaction parameter and weight fraction activity coefficient at infinite dilution were researched for …
Sensitive Determination Of Hydrazine Using Poly(Phenolphthalein), Au Nanoparticles Andmultiwalled Carbon Nanotubes Modified Glassy Carbon Electrode, Müge Hati̇p, Süleyman Koçak, Zekerya Dursun
Sensitive Determination Of Hydrazine Using Poly(Phenolphthalein), Au Nanoparticles Andmultiwalled Carbon Nanotubes Modified Glassy Carbon Electrode, Müge Hati̇p, Süleyman Koçak, Zekerya Dursun
Turkish Journal of Chemistry
This study reports a detailed analysis of an electrode material containing poly(phenolphthalein), carbon nanotubes and gold nanoparticles which shows superior catalytic effect towards to hydrazine oxidation in Britton?Robinson buffer (pH 10.0). Glassy carbon electrode was modified by electropolymerization of phenolphthalein (PP) monomer (poly(PP)/GCE) and the multiwalled carbon nanotubes (MWCNTs) was dropped on the surface. This modified surface was electrodeposited with gold nanoparticles (AuNPs/CNT/poly(PP)/GCE). The fabricated electrode was analysed the determination of hydrazine using cyclic voltammetry, linear sweep voltammetry and amperometry. The peak potential of hydrazine oxidation on bare GCE, poly(PP)/GCE, CNT/GCE, CNT/ poly(PP)/GCE, and AuNPs/CNT/poly(PP)/GCE were observed at 596 mV, …
A New Electrochemical Impedance Biosensor Based On Aromatic Thiol For Alpha-1 Antitrypsin Determination, Hülya Yağar, Hakki Mevlüt Özcan, Osman Mehmet
A New Electrochemical Impedance Biosensor Based On Aromatic Thiol For Alpha-1 Antitrypsin Determination, Hülya Yağar, Hakki Mevlüt Özcan, Osman Mehmet
Turkish Journal of Chemistry
Alpha-1 antitrypsin (A1AT) is one of the acute phase proteins which are synthesized in the liver. A1AT inhibits the activity of many proteases, but its main task is to protect the lungs from the attack of neutrophil elastase. In an autosomal hereditary disease known as alpha-1 antitrypsin deficiency, the A1AT level in blood serum decreases, increasing the risk of developing emphysema, liver apoptosis, and liver cancer. Thus, the detection of A1AT concentration in blood serum is very important. In this study, an impedimetric biosensor was developed, forming an SAM (self-assembled monolayer) with 4-mercaptophenylacetic acid (4MPA) on the surface of the …
Theoretical Investigation Of The Interaction Between The Metal Phthalocyanine [Mpc] A(M = Sc, Ti, And V; A = ?1, 0, And +1) Complexes And Formaldehyde, Nasim Hassani
Turkish Journal of Chemistry
Formaldehyde (FA, CH2O) is one of the toxic volatile organic compounds that cause harmful effects on the human body. In this work, the interaction of FA gas with metal phthalocyanine (MPc) molecules was studied by employing density functional theory calculations. A variety of [MPc] a (M = Sc, Ti, and V; a = -1, 0, and +1) complexes were studied, and the electronic properties, interaction energies, and charge transfer properties of all of the studied molecules were systematically discussed. Among the studied complexes, the Sc and Ti phthalocyanines were more reactive toward the adsorption of FA gas. Moreover, it was …
Cytotoxic And Apoptotic Potential Of Some Coumarin And 2-Amino-3-Carbonitrile Selenophene Derivatives In Prostate Cancer, Meti̇n Yildirim, Mehmet Erşatir, Badel Arslan, Eli̇fe Sultan Gi̇ray
Cytotoxic And Apoptotic Potential Of Some Coumarin And 2-Amino-3-Carbonitrile Selenophene Derivatives In Prostate Cancer, Meti̇n Yildirim, Mehmet Erşatir, Badel Arslan, Eli̇fe Sultan Gi̇ray
Turkish Journal of Chemistry
3-acetyl coumarin derivatives (1a-d) are formed as a result of condensation of salicylaldehyde derivatives and ethyl acetoacetate and were converted into coumarin-selenophene hybrid compounds (2a-d) in the basic medium by modified Gewald reaction in the presence of malononitrile and selenium. Products are characterized by nuclear magnetic resonance (NMR). The prepared compounds are screened for their anticancer activity against DU-145 cell line. In addition, selected target compounds are evaluated for apoptosis and oxidative stress on DU-145 (prostate carcinoma) cell lines.
The Application Of Qnmr For The Determination Of Rosuvastatin In Tablet Form, Gökhan Di̇kmen, Okan Uslu
The Application Of Qnmr For The Determination Of Rosuvastatin In Tablet Form, Gökhan Di̇kmen, Okan Uslu
Turkish Journal of Chemistry
In this study, quantative nuclear magnetic resonance (qNMR) method was used to determine the content of rosuvastatin in tablet. Linearity, range, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision were determined in validation study of rosuvastatin. Furthermore, validation study of rosuvastatin was performed with high performance liquid chromatography (HPLC). Uncertainties of qNMR and HPLC methods were determined using per EURACHEM/CITAC Guide CG 4 (3th edition), quantifying uncertainty in analytical measurement. qNMR and HPLC methods were linear in the ranges of 0.10 - 5.00 mg/mL and 0.001 - 0.0995 mg/mL, respectively and these lineraties indicate very good linearity …
Heavy Metal Removal With Magnetic Coffee Grain, Sevgi̇ Asliyüce Çoban, Ivo Safarik, Adi̇l Deni̇zli̇
Heavy Metal Removal With Magnetic Coffee Grain, Sevgi̇ Asliyüce Çoban, Ivo Safarik, Adi̇l Deni̇zli̇
Turkish Journal of Chemistry
The presence of heavy metals in environmental waters having an important place in the industrial waste is a major threat to viability. Heavy metals are transported to humans through the ecological cycle, damaging many tissues and organs. In recent years, agricultural and food waste can be used to remove heavy metals. At the present study, magnetically modified coffee grains which are alternative to conventional particle systems were prepared and heavy metal removal performances were investigated. The coffee grains used were magnetically modified by contact with water-based magnetic fluid. Magnetically modified coffee grains were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller …
Novel Nonperipheral Octa-3-Hydroxypropylthio Substituted Metallo-Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Electrochemical, Photochemical And Computational Properties, Ni̇lgün Kabay, Yasemi̇n Bayğu, Meti̇n Ak, İzzet Kara, Esra Nur Kaya, Mahmut Durmuş, Yaşar Gök
Novel Nonperipheral Octa-3-Hydroxypropylthio Substituted Metallo-Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Electrochemical, Photochemical And Computational Properties, Ni̇lgün Kabay, Yasemi̇n Bayğu, Meti̇n Ak, İzzet Kara, Esra Nur Kaya, Mahmut Durmuş, Yaşar Gök
Turkish Journal of Chemistry
The current study describes the synthesis, electrochemical, computational, and photochemical properties of octa (3-hydroxypropylthio) substituted cobalt (II) (4), copper (II) (5), nickel (II) (6) and zinc(II) (7) phthalocyanine derivatives. These novel compounds were characterized by elemental analysis, 1H, 13C NMR, FT-IR, UV-Vis, and MS. The redox behaviors of these metallo-phthalocyanines were investigated by the cyclic voltammetric method. The optimized molecular structure and gauge-including atomic orbital (GIAO) 1H and 13C NMR chemical shift values of these phthalocyanines in the ground state had been calculated by using B3LYP/6-31G(d,p) basis set. The outcomes of the optimized molecular structure were given and compared with …
Co2 Hydrogenation To Methanol And Dimethyl Ether At Atmospheric Pressure Using Cu-Ho-Ga/Γ-Al2o3 And Cu-Ho-Ga/Zsm-5: Experimental Study And Thermodynamic Analysis, Cansu Tuygun, Bahar İpek
Co2 Hydrogenation To Methanol And Dimethyl Ether At Atmospheric Pressure Using Cu-Ho-Ga/Γ-Al2o3 And Cu-Ho-Ga/Zsm-5: Experimental Study And Thermodynamic Analysis, Cansu Tuygun, Bahar İpek
Turkish Journal of Chemistry
CO2 valorization through chemical reactions attracts significant attention due to the mitigation of greenhouse gas effects. This article covers the catalytic hydrogenation of CO2 to methanol and dimethyl ether using Cu-Ho-Ga containing ZSM-5 and γ-Al2O3 at atmospheric pressure and at temperatures of 210 °C and 260 °C using a CO2:H2 feed ratio of 1:3 and 1:9. In addition, the thermodynamic limitations of methanol and DME formation from CO2 was investigated at a temperature range of 100?400 °C. Cu-Ho-Ga/γ-Al2O3 catalyst shows the highest formation rate of methanol (90.3 μmolCH3OH/gcat/h ) and DME (13.2 μmolDME/gcat/h) as well as the highest selectivity towards …
Size-Controllable Carbon Spheres Doped Ni (Ii) For Enhancing The Catalytic Oxidation Of Methanol, Yifen Hu, Pengyu Gao, Zhen Xu, Chuan Zhang, Lizhen Huang, Yunting Hu, Yarui An, Yingying Gu
Size-Controllable Carbon Spheres Doped Ni (Ii) For Enhancing The Catalytic Oxidation Of Methanol, Yifen Hu, Pengyu Gao, Zhen Xu, Chuan Zhang, Lizhen Huang, Yunting Hu, Yarui An, Yingying Gu
Turkish Journal of Chemistry
Ni(II)/CSs were prepared using a simple two-step hydrothermal method. The morphology and composition of the catalysts were studied with scanning electron microscope, transmission electron microscope, and X-ray diffraction. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed that the surface of the prepared carbon spheres was rich in hydroxyl groups, which was beneficial to remove CO intermediates, and therefore, improving the catalytic efficiency and the antipoisoning ability of the catalysts. The results of cyclic voltammetry and chronoamperometry showed that the electrocatalytic activity and stability of Ni(II)/CSs were higher than that of unloaded NiAc under alkaline environment. When the nickel content …
Vortex-Assisted Magnetic Solid Phase Extraction Of Pb And Cu In Some Herb Samples On Magnetic Multiwalled Carbon Nanotubes, Di̇lek Kamaş, Aslihan Karatepe, Mustafa Soylak
Vortex-Assisted Magnetic Solid Phase Extraction Of Pb And Cu In Some Herb Samples On Magnetic Multiwalled Carbon Nanotubes, Di̇lek Kamaş, Aslihan Karatepe, Mustafa Soylak
Turkish Journal of Chemistry
This study is the development of a new solid phase extraction method based on using magnetic multiwalled carbon nanotubes impregnated with 1-(2-pyridylazo)2-naphthol (PAN) for separation, preconcentration, and flame atomic absorption spectrometric determination of Pb(II) and Cu(II). Optimization of the method was done by investigating pH effect, amount of magnetic multiwalled carbon nanotubes impregnated with PAN, eluent type and volume, matrix effects, and volume of the sample. The optimum adsorbent amount was found to be 75 mg and the optimum pH value was found as 5.5. The detection limits were 16.6 μg L-1 for Pb(II) and 18.9 μg L-1 for Cu(II). …
New Chlorogenic Acid Derivatives And Triterpenoids From Scorzonera Aucheriana, İshak Eri̇k, Kami̇l Çoşkunçelebi̇, Serdar Makbul, Nuretti̇n Yayli
New Chlorogenic Acid Derivatives And Triterpenoids From Scorzonera Aucheriana, İshak Eri̇k, Kami̇l Çoşkunçelebi̇, Serdar Makbul, Nuretti̇n Yayli
Turkish Journal of Chemistry
Chromatographic separation of n-hexane and ethyl acetate fraction of a crude methanol extract obtained from aerial parts of the Scorzonera aucheriana DC collected from Sivas province of Turkey yielded nine natural compounds; two new 3-caffeoyl-quinic acid analogs (1-2), one new taraxasterol oleate (3), and six known triterpenoids taraxasterol (4), taraxasterol acetate (5), ptiloepoxide (6), lupeol (7), lupeol acetate (8), and β-sitosterol (9) were characterized. The structures of the isolated compounds were elucidated on the basis of NMR (1H, 13C, COSY, HMBC, HSQC, and TOCSY), UV, FT-IR and LC-Q-TOF-MS spectrometric data.
Toxicity Remission Of Paes On Multireceptors After Molecular Modification Through A3d-Qsar Pharmacophore Model Coupled With A Gray Interconnect Degree Method, Xinyi Chen, Yu Li
Toxicity Remission Of Paes On Multireceptors After Molecular Modification Through A3d-Qsar Pharmacophore Model Coupled With A Gray Interconnect Degree Method, Xinyi Chen, Yu Li
Turkish Journal of Chemistry
In the proposed model, the gray interconnect degree method was employed to process the acute toxicity values of phthalate acid esters (PAEs) to green algae, daphnia, mysid, and fish (predicted by EPI Suite software) and to obtain the comprehensive characterization value of the multireceptor toxicity effect (MTE) of PAEs. The 3D-QSAR pharmacophore model indicated that hydrophobic groups significantly affected the MTE of PAEs. Based on this, 16 PAEs derivative molecules with significantly decreased comprehensive characterization value (more than 10%) of the toxic effects of multireceptors were designed. Among them, 13 PAEs derivative molecules reduced the toxicity values (predicted by the …
Treatment Of Industrial Contaminants With Zero-Valent Iron- And Zero-Valent Aluminiumactivatedpersulfate: A Case Study With 3,5-Dichlorophenol And 2,4-Dichloroaniline, Olga Koba Ucun, Bahareh Montazeri̇, İdi̇l Arslan Alaton, Tuğba Ölmez Hanci
Treatment Of Industrial Contaminants With Zero-Valent Iron- And Zero-Valent Aluminiumactivatedpersulfate: A Case Study With 3,5-Dichlorophenol And 2,4-Dichloroaniline, Olga Koba Ucun, Bahareh Montazeri̇, İdi̇l Arslan Alaton, Tuğba Ölmez Hanci
Turkish Journal of Chemistry
Zero-valent iron (ZVI)- and zero-valent aluminium (ZVA)-activated persulfate (PS) oxidation procedure was applied to remove the industrial pollutants 3,5-dichlorophenol (3,5-DCP; 12.27 μM) and 2,4-dichloroaniline (2,4-DCA; 12.34 μM) from aqueous solutions. The effects of PS concentration and pH were investigated to optimize heterogeneous treatment systems. Negligible removals were obtained for both pollutants by individual applications of nanoparticles (1 g/L) and PS (1.00 mM). PS activation with ZVI resulted in 59% (1.00 mM PS; 1 g/L ZVI; pH 5.0; 120 min) and 100% (0.75 mM PS; 1 g/L ZVI; pH 5.0; 80 min) 3,5-DCP and 2,4-DCA removals, respectively. The ZVA/PS treatment system …
Fabrication And Characterization Of Amidoxime-Functionalized Silica Decorated Withcopper: A Catalytic Assembly For Rapid Reduction Of Dyes, Ijaz Ahmed Khan, Muhammad Inaam-Ul-Hassan, Hazrat Hussain, Syed Mujtaba Shah, Tariq Yasin
Fabrication And Characterization Of Amidoxime-Functionalized Silica Decorated Withcopper: A Catalytic Assembly For Rapid Reduction Of Dyes, Ijaz Ahmed Khan, Muhammad Inaam-Ul-Hassan, Hazrat Hussain, Syed Mujtaba Shah, Tariq Yasin
Turkish Journal of Chemistry
In this study, amidoxime-functionalized silica decorated with copper (AFS-Cu) was fabricated and tested for its catalytic application. Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction were employed to characterize its structure and morphology. The application of AFS-Cu as a catalyst for the catalytic reduction of methylene blue (MB) in aqueous media using NaBH$_{4}$ as reductant was evaluated. The ability to reuse as well as the effect of catalyst dose and pH of solution on the catalytic activity was investigated. The reduction of MB followed pseudo-first-order kinetics and the rate constant (k) was 0.6224 min$^{-1}$. …
Reusability And Regeneration Of Solid Catalysts Used In Ultrasound Assisted Biodieselproduction, Mahmut Rahi̇m Bayramoğlu, İbrahi̇m Korkut, Başak Temur Ergan
Reusability And Regeneration Of Solid Catalysts Used In Ultrasound Assisted Biodieselproduction, Mahmut Rahi̇m Bayramoğlu, İbrahi̇m Korkut, Başak Temur Ergan
Turkish Journal of Chemistry
Reusability of two heterogeneous catalysts in ultrasound (US) assisted biodiesel production was investigated in comparison to each other. An ultrasound (US) generator (200 W, 20 kHz) equipped with a horn type probe (19 mm) was used. Regeneration experiments were planned according to second order central composite design (CCD) method. After the eighth use of the catalysts, biodiesel yield decreased from 99.1% to 90.4% for calcined calcite (CaO) and from 98.8% to 89.8% for calcined dolomite (CaO.MgO). Furthermore, regeneration of spent catalysts by calcination was investigated; optimum temperature and time were found as 750 °C and 90 min, lower than fresh …
Dispersive Liquid-Liquid Microextraction For The Isolation And Hplc-Daddetermination Of Three Major Capsaicinoids In Capsicum Annuum L., Jude Caleb, Usama Alshana, Azmi̇ Hanoğlu, İhsan Çaliş
Dispersive Liquid-Liquid Microextraction For The Isolation And Hplc-Daddetermination Of Three Major Capsaicinoids In Capsicum Annuum L., Jude Caleb, Usama Alshana, Azmi̇ Hanoğlu, İhsan Çaliş
Turkish Journal of Chemistry
Dispersive liquid-liquid microextraction (DLLME) was combined with high-performance liquid chromatography-diodearray detector (HPLC-DAD) for the extraction and quantitation of three major capsaicinoids (i.e. capsaicin, dihydrocapsaicin and nordihydrocapsaicin) from pepper (Capsicum annuum L.). Chloroform (extraction solvent, 100 μL), acetonitrile (disperser solvent, 1250 μL) and 30 s extraction time were found optimum. The analytes were back-extracted into 300 μL of 50 mM sodium hydroxide/ methanol, 45/55% (v/v), within 15 s before being injected into the instrument. Enrichment factors ranged from 3.3 to 14.7 and limits of detection from 5.0 to 15.0 μg g$^{-1}$. Coefficients of determination (R$^{2}$) and %RSD were higher than 0.9962 …
Detection Of Alkanolamines In Liquid Cement Grinding Aids By Hplc Coupled Withevaporative Light Scattering Detector, Cheng Li, Wenfang Song, Yubai Shi, Zhiwei Qing
Detection Of Alkanolamines In Liquid Cement Grinding Aids By Hplc Coupled Withevaporative Light Scattering Detector, Cheng Li, Wenfang Song, Yubai Shi, Zhiwei Qing
Turkish Journal of Chemistry
Triethanolamine (TEA), triisopropanolamine (TIPA), diethanol isopropanolamine (DEIPA) are necessary cement additives, and knowing their contents is needed for quality control and also to understand final properties of the cement. Whether it is the production of grinding aids, technical research and development or application research all involve the detection of grinding aids. This work developed a simple analytical technique for the simultaneous analysis of these alkanolamines in liquid cement grinding aids using high-performance liquid chromatography (HPLC) combined with evaporative light scattering detection (ELSD). HPLC was conducted by an XBridge C18 column (with dimensions 4.6 × 250 mm and 5 ?m particles) …
Enhanced Ethanol Sensing Properties Of Wo$_{3}$ Modified Tio$_{2}$ Nanorods, Bekzat Abdikadyr, Alp Kiliç, Onur Alev, Serkan Büyükköse, Zafer Zi̇ya Öztürk
Enhanced Ethanol Sensing Properties Of Wo$_{3}$ Modified Tio$_{2}$ Nanorods, Bekzat Abdikadyr, Alp Kiliç, Onur Alev, Serkan Büyükköse, Zafer Zi̇ya Öztürk
Turkish Journal of Chemistry
Pristine and WO$_{3}$ decorated TiO$_{2}$ nanorods (NRs) were synthesised to investigate n-n-type heterojunction gas sensing properties. TiO$_{2}$ NRs were fabricated via hydrothermal method on fluorine-doped tin oxide coated glass (FTO) substrates. Then, tungsten was sputtered on the TiO$_{2}$ NRs and thermally oxidised to obtain WO$_{3}$ nanoparticles. The heterostructure was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy. Fabricated sensor devices were exposed to VOCs such as toluene, xylene, acetone and ethanol, and humidity at different operation temperatures. Experimental results demonstrated that the heterostructure has better sensor response toward ethanol at 200 °C. Enhanced sensing …
Rhenium/Rhenium Oxide Nanoparticles Production Using Femtosecond Pulsed Laserablation In Liquid, Abdullah Kepceoğlu, Yasemi̇n Gündoğdu, Adem Sarilmaz, Mustafa Ersöz, Faruk Özel, Hamdi̇ Şükür Kiliç
Rhenium/Rhenium Oxide Nanoparticles Production Using Femtosecond Pulsed Laserablation In Liquid, Abdullah Kepceoğlu, Yasemi̇n Gündoğdu, Adem Sarilmaz, Mustafa Ersöz, Faruk Özel, Hamdi̇ Şükür Kiliç
Turkish Journal of Chemistry
In this study, rhenium/rhenium oxide nanoparticles (Re / ReO$_{3}$ NPs) have been produced for the first time in ultrapure water by using Femtosecond Pulsed Laser Ablation in Liquid (fsPLAL) method. X-Ray Diffraction (XRD) measurements and results obtained for NPs show the existence of well-crystallized peaks and preferred phases. Re NPs have hexagonal structure while ReO$_{3}$ NPs have the perovskite-like cubic crystal structures. The Re / ReO$_{3}$ ratio is also determined to be 53 / 47 with ~ 20 nm crystallite size, while pure ReO$_{3}$ crystallite sizes were measured to be ~ 25 nm. The TEM results have shown that the …
Accelerated Fe$^{Iii}$/Fe$^{Ii}$ Redox Cycle Of Fenton Reaction System Using Pd/Nh$_{2}$-Mil-101(Cr)And Hydrogen, Zhong-Xing Liu, Xin Liu, Yong Li, Shi-Qian Gao
Accelerated Fe$^{Iii}$/Fe$^{Ii}$ Redox Cycle Of Fenton Reaction System Using Pd/Nh$_{2}$-Mil-101(Cr)And Hydrogen, Zhong-Xing Liu, Xin Liu, Yong Li, Shi-Qian Gao
Turkish Journal of Chemistry
In this paper, a novel improvement in the catalytic Fenton reaction system named MHACF-NH$_{2}$-MIL-101(Cr) was constructed based on H$_{2}$ and Pd/NH$_{2}$-MIL-101(Cr). The improved system would result in an accelerated reduction in Fe$^{III}$, and provide a continuous and fast degradation efficiency of the 10 mg L$^{-1}$ 4-chlorophenol which was the model contaminant by using only trace level Fe$^{II}$. The activity of Pd/NH$_{2}$-MIL-101(Cr) decreased from 100% to about 35% gradually during the six consecutive reaction cycles of 18 h. That could be attributed to the irreversible structural damage of NH$_{2}$-MIL-101(Cr). Key words:
Comparative Study On The Effect Of Precursors On The Morphology And Electronicproperties Of Cds Nanoparticles, Kevin I. Y. Ketchemen, Sixberth Mlowe, Linda D. Nyamen, Peter T. Ndifon, Neerish Revaprasadu
Comparative Study On The Effect Of Precursors On The Morphology And Electronicproperties Of Cds Nanoparticles, Kevin I. Y. Ketchemen, Sixberth Mlowe, Linda D. Nyamen, Peter T. Ndifon, Neerish Revaprasadu
Turkish Journal of Chemistry
Cadmium dithiocarbamate and cadmium ethyl xanthate complexes were synthesized and characterized by microanalysis, Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analyses. The complexes were employed as molecular precursors for the fabrication of CdS nanoparticles in hexadecylamine (HDA) and oleylamine (OLA) at a temperature of 250 °C. Spherical and oval shaped particles with sizes ranging from 9.93 ± 1.89 to 16.74 ± 2.78 nm were obtained in OLA while spherical, oval and rod shaped particles with sizes ranging from 9.40 ± 1.65 to 29.90 ± 5.32 nm were obtained in HDA. Optical properties of the nanoparticles showed blue shifts as compared …
Preparation Of Glutathione Loaded Nanoemulsions And Testing Of Hepatoprotectiveactivity On Thle-2 Cells, Ozan Yeşi̇ltepe, Emi̇ne Güler Çeli̇k, Caner Geyi̇k, Zi̇nar Pinar Gümüş, Di̇lek Odaci Demi̇rkol, Hakan Coşkunol, Suna Ti̇mur
Preparation Of Glutathione Loaded Nanoemulsions And Testing Of Hepatoprotectiveactivity On Thle-2 Cells, Ozan Yeşi̇ltepe, Emi̇ne Güler Çeli̇k, Caner Geyi̇k, Zi̇nar Pinar Gümüş, Di̇lek Odaci Demi̇rkol, Hakan Coşkunol, Suna Ti̇mur
Turkish Journal of Chemistry
To improve bioavailability and stability of hydrophobic and hydrophilic compounds, nanoemulsions are good alternatives as delivery systems because of their nontoxic and nonirritant nature. Glutathione (GSH) suffers from low stability in water, where its encapsulation in nanoemulsions is a powerful strategy to its stability in aqueous systems. The aim of this study was to obtain nanoemulsions from the hydrophobic/hydrophilic contents of N. sativa seed oil so as to improve GSH stability along with bioavailability of N. sativa seed oil. Then, the prepared nanoemulsions were tested for in vitro hepatoprotective activity against ethanol toxicity. To the best of our knowledge, there …
The Effect Of H$_{2}$O On The Sulfation Of Havelock Limestone Under Oxy-Fuel Conditions In Athermogravimetric Analyser, Murat Varol, Edward John Anthony, Arturo Macchi
The Effect Of H$_{2}$O On The Sulfation Of Havelock Limestone Under Oxy-Fuel Conditions In Athermogravimetric Analyser, Murat Varol, Edward John Anthony, Arturo Macchi
Turkish Journal of Chemistry
A gas mixture representing oxy-fuel combustion conditions was employed in a thermogravimetric analyser to determine the effect of water vapor and SO$_{2}$ concentration on limestone sulfation kinetics over the temperature range of 800 to 920 °C. Here, experiments used small samples of particles (4 mg), with small particle sizes (d$_{p}$ < 38 μm) and large gas flow rates (120 mL/min@ NTP) in order to minimize mass transfer interferences. The gas mixture contained 5000 ppm$_{v}$ SO$_{2}$, 2% O$_{2}$, and the H$_{2}$O content was changed from 0% to 25% with the balance CO$_{2}$. When water vapor was added to the gas mixture at lower temperatures (800-870 °C), the limestone SO$_{2}$ capture efficiency increased. However, as the temperature became higher, the enhancement in total conversion values decreased. As expected, Havelock limestone at higher temperatures (890 °C, 920 °C, and 950 °C) experienced indirect sulfation and reacted at a faster rate than for lower temperatures (800-870 °C) for direct sulfation over the first five minutes of reaction time. However, the total conversion of Havelock limestone for direct sulfation was generally greater than for indirect sulfation.
Synthesis Of Some Nh- And Nh,S- Substituted 1,4-Quinones, Ayşeci̇k Kaçmaz
Synthesis Of Some Nh- And Nh,S- Substituted 1,4-Quinones, Ayşeci̇k Kaçmaz
Turkish Journal of Chemistry
A series of NH-substituted-1,4-quinones, possessing one, two, three or not chlorine, were synthesized by the reaction between different quinones (p-chloranil (1), p-toluquinone (2), or 2,3-dichloro-1,4-naphthoquinone (3)) and (-)-cis-myrtanylamine (5) via nucleophilic reactions. Moreover, 2-bromo-1,4-naphthoquinone (4) was reacted with 2-(methylthio)ethylamine (11) to produce aminosubstituted naphthoquinones (12 and 13), bearing with bromine and not bromine. In addition, 2-bromo-1,4-naphthoquinone (4) was reacted with 4?-aminodibenzo-18-crown-6 (14) and 4'-aminobenzo-18-crown-6 (16) to yield crown-containing 1,4-naphthoquinones (15 and 17), respectively. New compounds were characterized, providing 1H NMR, 13C NMR, FTIR, MS-ESI, UV/Vis and elemental analysis.
Spectroscopic Investigation Of Defect-State Emission In Cdse Quantum Dots, Gülhan Güleroğlu, Caner Ünlü
Spectroscopic Investigation Of Defect-State Emission In Cdse Quantum Dots, Gülhan Güleroğlu, Caner Ünlü
Turkish Journal of Chemistry
CdSe quantum dots are the most studied Cd-based quantum dots with their high quantum yield, high photostability, narrow emission band, and easy synthesis procedure. They are frequently used to develop light emitting diode (LED) due to their unique photo¬physical properties; however, their narrow emission band causes a challenge to design white LEDs because white light emission requires emission in multiple wavelengths with broad emission bands. Here in this study, we developed CdSe quantum dots with a narrow band-edge emission band and broad defect-state emission band through a modified two-phase synthesis method. Our results revealed that defect-state emission is directly linked …