Chemistry Commons^™

Fabrication Of Electrospun Tio2/Polymer Composite Nanofibers For Photocatalysis And Degradation Of Toxins, Danielle L. Mccarthy

Graduate Dissertations and Theses

Our society has made significant advancements in technology as it continues to grow in size which in turn has led to an accumulating amount of toxic threats. Some types of harmful pollution our society is currently facing include industrial waste such as organic dyes, pharmaceutical pollution and chemical warfare agents (CWAs). To date the nerve agent, O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate), also known as VX, is the world’s most lethal chemical substance. Some of these deadly nerve agents have been employed in various conflict and terrorist attacks. Currently available CWA degradation techniques include incineration and water hydrolysis followed by biotreatment …

Forensic Characterization Of Dyes From Synthetic Textile Fibers Exposed To Outdoor And Laundering Effects By Ultra Performance Liquid Chromatography And Spectral Analysis, Molly Rebecca Burnip

Theses and Dissertations

Textile fibers found in an investigation are trace evidence that can connect a suspect to a victim or crime scene. Examination involves comparison of the color and morphology of a questioned fiber to a known fiber with optical spectroscopy. Fibers are considered class evidence, so evaluating more characteristics increases their significance as evidence if a match cannot be excluded. Acrylic, nylon, and polyester are textile polymers that require different extraction solvents based on the polymer chemistry. Methods have been developed for UPLC analysis of basic dyes on acrylic, acid on nylon, and disperse dyes on polyester. After microextraction from single …

Synthesis And Structural Properties Of $N$-3,4-(Dichlorophenyl)-3-Oxo-3- Phenyl-2-(Phenylcarbonyl)Propanamide And Its Cu(Ii) Complex, Ahmet Oral Sarioğlu, Tuğba Taşkin Tok, Mehmet Akkurt, Muhammad Nawaz Tahir, Mehmet Sönmez

Turkish Journal of Chemistry

A new N-carboxamide compound (3) was synthesized by the reaction of dibenzoylaceticacid-$N$-carboxyethyla\-mide (1) and 3,4-dichloroaniline (2). The $N$-(3,4-dichlorophenyl)-3-oxo-3-phenyl-2-(phenylcarbonyl) propanamide (3) subsequently reacted with Cu salt to produce its Cu(II) complex compound (4). The compounds were characterized by analytical and spectral methods. In addition, X-ray diffraction was performed to characterize and obtain detailed information about the structure of 3. The fully optimized geometries of compounds 3 and 4 were calculated at different basis sets by using the Gaussian09 (G09) software to investigate their 3D geometries and electronic structures. Comparisons between the calculated and experimental data including molecular structures, fundamental vibrational modes, …

Purification And Characterization Of Mitochondrial Thioredoxin Reductase Enzyme From Rainbow Trout (Oncorhynchus Mykiss) Liver And Investigation Of The In Vitro Effects Of Some Metal Ions On The Enzyme, İlknur Özgençli̇, Mehmet Çi̇ftci̇

Turkish Journal of Chemistry

Thioredoxin reductase (E.C 1.6.4.5.; TrxR) is an enzyme belonging to the flavoprotein family of pyridine nucleotide-disulfide oxidoreductases. In this study, mitochondrial TrxR enzyme was purified from rainbow trout mitochondria. Thanks to the 2 consecutive procedures (preparation of homogenate and 2',5'-ADP Sepharose 4B affinity chromatography), the enzyme, having the specific activity of 11.9 EU mg protein-1, was purified with a yield of 2.38{\%} and 672-fold. The purity of the enzyme was monitored and the molecular weight of its subunits was calculated as 70 kDa by SDS-PAGE. The native molecular mass of the enzyme was found to be approximately 151 kDa by …

Co$_{2}$ Adsorption Behavior And Kinetics On Chemically Modified Activated Carbons, Burcu Selen Çağlayan, Ahmet Erhan Aksoylu

Turkish Journal of Chemistry

CO$_{2}$ adsorption capacities of activated carbon-based adsorbents subjected to different treatments, such as HNO$_{3}$ oxidation, air oxidation, alkali impregnation, and heat treatment under helium gas atmosphere, were determined by gravimetric analyses and reported previously by our group. In the current work, the experimental adsorption isotherms of these modified activated carbon samples were fitted to Langmuir, Freundlich, and Dubinin--Radushkevich (D-R) models. The best fits were obtained to the D-R equation, indicating competitive or multilayer CO$_{2}$ adsorption occurring in the micropores of the adsorbents. Air oxidation followed by alkali impregnation led to the highest micropore volume, ranging between 0.259 and 0.298 g.CO$_{2}$/g.adsorbent, …

Development Of A Method For The Determination Of Cadmium Levels In Seawater By Flame Atomic Absorption Spectrometry Using An Online Cloud-Point Extraction System, Rafael Vasconcelos Oliveira, Uelber Silva Vieira, Mardson Vasconcelos Maciel, Thais Souza Neri, Graziele Santos Sales, Rebeca Moraes Menezes, Valfredo Azevedo Lemos

Turkish Journal of Chemistry

A new system was developed for the preconcentration and determination of cadmium levels in water following online cloud-point extraction and analysis by flame atomic absorption spectrometry. The method uses cloud-point extraction of the complex formed between Cd(II) ions and the reagent 2-(5-bromo-2'-thiazolylazo)-$p$-cresol (Br-TAC) using Triton X-114 as a surfactant. The main steps of the procedure, extraction, filtration, and detection were conducted online. Parameters that influence the experimental conditions of online preconcentration systems were examined, including pH, concentration of reagent and surfactant, and flow of sample and eluent. The limit of detection of the method is 0.2 $\mu $g L$^{-1}$. The …

Supplemental Materials For Building Data And Information Literacy In The Undergraduate Chemistry Curriculum, Yasmeen Shorish, Barbara A. Reisner

Department of Chemistry and Biochemistry - Faculty Scholarship

Course syllabus from Chem 481, Fall 2015, to supplement the chapter "Building Data and Information Literacy in the Undergraduate Chemistry Curriculum" in the monograph Integrating Library and Information Literacy Into Chemistry Curricula - ACS Symposium Series, ACS Publications.

Building Data And Information Literacy In The Undergraduate Chemistry Curriculum, Yasmeen Shorish, Barbara A. Reisner

Department of Chemistry and Biochemistry - Faculty Scholarship

The Literature and Seminar sequence at James Madison University has been used to develop the chemistry information literacy skills of chemistry majors for over four decades. These courses have been continually updated to emphasize information literacy skills for the twenty-first century. This chapter describes the methods that have been developed to improve chemical, data and general information literacy at a large, public, primarily undergraduate institution. The focus of the first semester course, described in this chapter, is on skill building rather than teaching specific resources. It is a model of integration and collaboration between chemistry faculty and chemistry librarians. Changes …

A General Valence-Length Correlation For Determining Bond Orders: Application To Carbon-Carbon And Carbon-Hydrogen Chemical Bonds, F. D. Hardcastle

Journal of the Arkansas Academy of Science

A quantum-mechanical LCAO approach was used to derive Pauling’s popular empirical bond valencelength relationship s = exp((R₀-R)/b), where s is the bond order or bond valence associated with bond length R, and R₀ and b are fitting parameters. An expression for the b “empirical” fitting parameter is derived in terms of atomic orbital exponents. The b parameters calculated from the atomic orbital exponents are consistent with optimized b parameters. In general, atomic orbital exponents may be used to determine bond valence-length relationships for any chemical bond regardless of valence state, oxidation number, physical or chemical environment. In this study, almost …

Electropolymerized Layersas Selective Membranesin First Generation Uric Acid Biosensors, Kaiwen Chen, Grace E. Conway, Gregory A. Hamilton, Matthew L. Trawick, Michael C. Leopold

Chemistry Faculty Publications

Electropolymerized films that can serve as semi-permeable membranes and provide selectivity within a xerogel-based, 1^stgeneration biosensor assembly are explored in this study. Layered biosensing schemes of this nature rely primarily upon an electropolymerized ad-layer to supplement the xerogel and provide effective selectivity for detection of a targeted analyte. While effective electropolymers have been established for glucose sensing, the adaptation of the strategy to other analytes of clinical importance hinges upon the systematic evaluation of electropolymerized films to identify a selective film. Uric acid is a key species in the diagnosis/monitoring of a number of diseases and conditions. An …

Renewable Bio-Based Intermediates, Monomers And Polymeric Materials From Plant Oils, Liang Yuan

Theses and Dissertations

In the dissertation work, new chemical intermediates, monomers and thermoplastic polymers were derived from renewable soybean oil. Elastomers were further developed using monomers and polymers from soybean oil. The properties of these polymeric materials were characterized and discussed.

In Chapter 1, the overall background and recent development polymers from renewable biomass, especially plant oils, is introduced. Major research objectives of my doctoral research were described.

The first section of the dissertation, on the preparation of renewable intermediates, novel monomers and homopolymers, is provided in Chapter 2 and Chapter 3. In Chapter 2, amidation of soybean oil with amino alcohols was …

Comparative Study For The Separation, Preconcentration, And Determination Of Copper And Cadmium In Real Samples By Using Two Different Ligands, Hami̇de Elvan Bayrak, Volkan Numan Bulut, Mehmet Tüfekçi̇, Hacer Bayrak, Celal Duran, Mustafa Soylak

Turkish Journal of Chemistry

Two new solid phase extraction methods have been developed for simultaneous separation and preconcentration of Cu(II) and Cd(II) in some food and environmental samples before their determination by flame atomic absorption spectrometry (FAAS). One of these methods is based on the absorption of the Cu(II) and Cd(II) complexes with [3-(cyanomethyl)-5-(4-methylphenyl)-4$H$-1,2,4-triazol-4-yl]carbamate (L1) and the other is based on the absorption of the Cu(II) and Cd(II) complexes with 4-(4-methylphenyl)-5-{[pyridine-4-yl-4$H$-1,2,4-triazole-3-yl)thio]methyl}-4$H$-1,2,4-triazole-3-thiol (L2) on Amberlite XAD-1180 resin. The metal complexes are retained on resin at pH 6.0 and eluted with 1.0 mol L$^{-1}$ HCl in acetone in both methods. After the optimum conditions were determined, …

Square Wave Voltammetric Determination Of Valproic Acid In Pharmaceutical Preparations, Ebru Türköz Acar, Ati̇ye Nur Onar

Turkish Journal of Chemistry

The electrochemical behavior of valproic acid (VAL) was investigated using square wave voltammetry, cyclic voltammetry, and sampled direct current polarography and a new square wave voltammetric method was developed for determination of VAL in pharmaceutical preparations. VAL showed two reduction peaks at about --0.2 V and --0.8 V vs. Ag/AgCl 3 M KCl with a hanging mercury drop electrode in 0.05 M pH 3.3 Britton--Robinson (BR) buffer. These peaks were named peak I and peak II, respectively. The types of limiting current of both peaks were determined as diffusion controlled based on cyclic voltammetry studies. A linear calibration graph was …

A Convenient Route For The Synthesis Of New Thiadiazoles, Abdelwahed Sayed, Yasser Zaki, Emad Aish

Turkish Journal of Chemistry

The present work describes the preparation of new thiadiazoles through a simple intramolecular reaction of mono- and bis-hydrazonoyl halides with methyl hydrogen phenyl carbonimidodithioate or methyl-2-arylidene hydrazinecarbodithioate. The synthetic method involves nucleophilic substitution followed by intramolecular cyclization reactions mediated by evolution of methanethiol. The structures of the title compounds were elucidated by elemental analyses, and FTIR, MS and NMR spectra.

Synthesis Of Novel Chiral Bisoxazoline Ligands With A Norbornadiene Backbone: Use In The Copper-Catalyzed Enantioselective Henry Reaction, Rabi̇a Deli̇kuş, Emi̇ne Çakir, Nadi̇r Demi̇rel, Meti̇n Balci, Betül Karataş

Turkish Journal of Chemistry

Novel chiral bisoxazoline ligands based on norbornadiene were synthesized and used for the asymmetric Henry reaction. Various aromatic aldehydes were converted into chiral $\beta $-nitro alcohols with high yields and moderate to acceptable enantioselectivities under the optimized reaction conditions.

Immobilization Of Laccase Onto A Porous Nanocomposite: Application For Textile Dye Degradation, Sedef İlk, Deni̇z Demi̇rcan, Semran Sağlam, Necdet Sağlam, Zakir M. O. Rzayev

Turkish Journal of Chemistry

Poly(MA-\textit{alt}-MVE)-$g$-PLA/ODA-MMT nanocomposite was prepared by self-catalytic interlamellar graft copolymerization of L-lactic acid (LA) onto poly(maleic anhydride-\textit{alt}-methyl vinyl ether) copolymer in the presence of octadecyl amine-montmorillonite (ODA-MMT) organoclay. FTIR, $^{1}$H ($^{13}$C) NMR, XRD, and SEM-TEM were utilized for characterizing the resultant nanocomposite. Laccase from \textit{Trametes versicolor} was immobilized onto the prepared nanocomposite by adsorption or covalent coupling. Decolorization of Reactive Red 3 from aqueous solution by laccase immobilized on the nanocomposite was studied in different conditions (pH, temperature, dye concentration, and reaction time) to investigate the decolorization activity with repeated use and storage. The results indicated that more than 77{\%} of …

Synthesis Of Graft Copolymer Of Kappa-Carrageenan Using Microwave Energy And Studies Of Swelling Capacity, Flocculation Properties, And Preliminary Acute Toxicity, Tapan Kumar Giri, Minakshi Pradhan, Dulal Krishna Tripathi

Turkish Journal of Chemistry

Grafting of acrylamide (AAm) onto kappa-carrageenan (KC) was carried out using microwave irradiation in the presence of ammonium persulfate (APS) as initiator. The effect of reaction variables including the concentration of APS, AAm, and KC; time duration; and microwave power was studied. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) were carried out to characterize the graft copolymer. The graft copolymer possesses slightly sensitive activities to external pH and shows reversible on--off switching swelling characteristics. Flocculation efficacy of the graft copolymer was studied in coal fine suspension toward potential application as …

Enhanced Delivery Of Epirubicin By Polyoxometalate-Based Magnetic Nanocarriers: Controlled Drug Loading And Ph-Sensitive Drug Release, Ezzat Rafiee, Nasibeh Rahpeyma

Turkish Journal of Chemistry

A series of polyoxometalate-based magnetic nanoparticles were developed as novel carriers for anticancer drugs. Characterization of the nanoparticles was done by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), wavelength dispersive X-ray (WDX), and laser particle size analyzer. Epirubicin (EPI) was selected as a model drug. EPI loading efficiency, EPI loading content, and EPI release profiles were studied. Drug loading was controlled using acid-base titration since H$^{+}$ was released during the loading process. Based on these investigations, an efficient EPI delivery system was introduced. It showed high EPI-loading capacity (35.2 wt.{\%}) and high EPI loading …

Heterogeneous Fenton-Like Degradation Of Acid Red 17 Using Fe-Impregnated Nanoporous Clinoptilolite: Artificial Neural Network Modeling And Phytotoxicological Studies, Alireza Khataee, Mehrangiz Fathinia, Soghra Bozorg

Turkish Journal of Chemistry

Heterogeneous Fenton-like removal of Acid Red 17 (AR17) from aqueous solution was investigated. Fe-impregnated nanoporous clinoptilolite (Fe-NP-Clin) was prepared by an impregnation method and used as a catalyst. A complete characterization including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), inductively coupled plasma (ICP), and Brunauer--Emmett--Teller (BET) analyses was done to describe the physical and chemical properties of NP-Clin and Fe-NP-Clin samples. The effects of five operational parameters, i.e. solution pH, H$_{2}$O$_{2}$ dosage, catalyst loading, AR17 concentration, and reaction time, on the removal efficiency of AR17 were studied. For the first time, an artificial neural network …

New Antimicrobial Biscembrane Hydrocarbon And Cembranoid Diterpenes From The Soft Coral Sarcophyton Trocheliophorum, Muhammad Zubair, Walied Alarif, Khalid Al-Footy, Mohamed Ph, Magda Ali, Salim Basaif, Sultan Al-Lihaibi, Seif-Eldin Ayyad

Turkish Journal of Chemistry

A new tetracyclic biscembrane hydrocarbon, trocheliane (1), along with two new cembranoid diterpenes, sarcotrocheldiol A (2) and B (3), and the known diterpene cembrene-C (4), were isolated from the Red Sea soft coral Sarcophyton trocheliophorum. The structures and relative stereochemistry of the compounds were elucidated by interpretation of MS, 1 D NMR, and 2 D NMR experiments. The sensitivity of some pathogenic bacteria used as test organisms to the new compounds 1-3 was determined. 1 showed appreciable antimicrobial activity with the diameter of inhibition zones ranging from 11 to 18 mm. 1 was active against the two multidrug resistant bacteria …

Simple And Rapid Voltammetric Determination Of Boron In Water And Steel Samples Using A Pencil Graphite Electrode, Lokman Li̇v, Nuri̇ Naki̇boğlu

Turkish Journal of Chemistry

This paper presents a simple, rapid, and accurate voltammetric method for determination of boron in water and steel samples using a disposable pencil graphite electrode. The oxidation of Tiron in the boron-Tiron complex in phosphate buffer at pH 7.5 was measured as a response. Type and concentration of supporting electrolyte, pH, ionic strength, Tiron concentration, scan rate, step amplitude, pulse amplitude, and pencil grade were investigated as the parameters affecting the peak current. The limit of detection (3s) was estimated as 84 $\mu $g/L. The relative standard deviation of the method was 4.6 for 1 mg B/L (N = 7). …

Ecofriendly One-Pot Synthesis And Antiviral Evaluation Of Novel Pyrazolyl Pyrazolines Of Medicinal Interest, Sobhi Gomha, Magda Abdalla, Mohamad Abd El-Aziz, Nany Serag

Turkish Journal of Chemistry

Ethyl 3-acetyl-1,5-diphenyl-1$H$-pyrazole-4-carboxylate reacts with a variety of arylaldehydes by grinding method in the presence of a catalytic amount of sodium hydroxide at ambient temperature to give the respective chalcones. The latter compounds react also by grinding method with nitrogen nucleophiles such as hydrazine hydrate, phenylhydrazine, and thiosemicarbazide to afford the corresponding pyrazol-3-yl pyrazolines. A series of 6-pyrazolylpyrimidine-2-thione derivatives were prepared by reaction of the above chalcones with thiourea by grinding method in the presence of a catalytic amount of sodium hydroxide at room temperature. In addition, 7-pyrazolylpyridopyrimidine-3-thione was prepared by reaction of chalcone with 6-aminothiouracil. All the newly synthesized compounds …

Synthesis, And Prediction Of Molecular Properties And Antimicrobial Activity Of Some Acylhydrazones Derived From $N$-(Arylsulfonyl)Methionine, Esra Tatar, Sevi̇l Şenkardeş, Hasan Erdi̇nç Selli̇tepe, Şükri̇ye Güni̇z Küçükgüzel, Şengül Alpay Karaoğlu, Ari̇f Bozdeveci̇, Erik De Clercq, Christophe Pannecouque, Tai̇bi̇ Ben Hadda, İlkay Küçükgüzel

Turkish Journal of Chemistry

A series of 38 new acylhydrazones [3-40], derived from (2$S)$-4-(methylsulfanyl)-2-[[(4-methylphenyl)sulfonyl] amino]butanoic acid hydrazide [2], were synthesized and evaluated for their anti-HIV and antimicrobial activity with the further aim to develop acylhydrazones carrying an amino acid side chain. All tested compounds possess stronger activity against gram (+) bacteria. Compound 23 was found active against methicillin-resistant Staphylococcus aureus (MRSA) with a MIC value of 3.9 $\mu $g/mL. The MIC value of compound 30 against Enterococcus faecalis, Listeria monocytogenes, and Bacillus cereus was 8 $\mu $g/mL. A computational study for prediction of ADME and drug-like properties (solubility, drug-likeness, and drug score) as well …

The Mediatory Activity Of Meso-Tetraphenylporphyrin Iron(Iii) Complex Immobilized In Nafion Film On A Pt Electrode In The Oxidation Of 1,2- And 1,4-Hydroquinones, Slawomir Domagala, Slawomira Skrzypek, Michal Cichomski, Andrzej Leniart

Turkish Journal of Chemistry

This paper presents the results of an investigation of the properties of a modified platinum electrode with meso-tetraphenylporphyrin iron(III) complex immobilized in Nafion film and its catalytic activity in the electrochemical oxidation of selected hydroquinone and catechol derivatives. The redox activity of iron complexes of porphyrins was characterized in aqueous solutions of perchloric acid by means of cyclic voltammetry and differential pulse voltammetry. Both the increase in the anodic peak currents of the investigated compounds during oxidation on the platinum electrode modified with meso-tetraphenylporphyrin iron(III) complex immobilized in Nafion film (FeTPhP/Nafion/Pt) and the considerable decrease in the cathodic peak currents …

Electrochemical Investigation Of2-[8-Hydroxyquinoline-5-Yl)Azo]Benzo[$C$]Cinnoline On A Platinum Electrode In Dimethysulfoxide, Funda Öztürk, Zehra Yazan, Oznur Olmez, Emi̇ne Kiliç, Esma Kiliç

Turkish Journal of Chemistry

2-[8-hydroxyquinoline-5-yl)azo]benzo[c]cinnoline was synthesized for the first time and shown to possess electrochromic characteristic, i.e. changing color during the forward and back electrolysis at --1.35 V and 0.00 V, respectively, in DMSO medium. Therefore, the electrochemical investigation of this compound appears to be worthwhile. The electrochemical reduction of 2-[8-hydroxyquinoline-5-yl)azo]benzo[c]cinnoline was investigated by cyclic voltammetry, controlled potential electrolysis, and chronoamperometry techniques in the presence of 0.10 mol L$^{-1}$ tetrabutylammonium tetrafluoroborate in dimethyl sulfoxide at platinum electrode. 2-[8-Hydroxyquinoline-5-yl)azo]benzo[c] cinnoline displays three sharp cathodic peaks and three anodic peaks in the cyclic voltammogram. The diffusion coefficients and the number of electrons transferred were calculated …

Synthesis Of Novel Thiazolylpyrazoline Derivatives And Evaluation Of Their Antimicrobial Activities And Cytotoxicities, Aouatef Tabbi, Zafer Asim Kaplancikli, Dahmane Tebbani, Leyla Yurttaş, Zerri̇n Cantürk, Özlem Atli, Merve Baysal, Gülhan Turan Zitouni

Turkish Journal of Chemistry

Several novel thiazolylpyrazoline derivatives were synthesized by reacting substituted 3,5-diaryl-1-thiocarba\-moyl-2-pyrazolines with phenacylbromides. The structures of the synthesized compounds were confirmed by IR, $^{1}$H NMR, $^{13}$C NMR, and MS spectral data. Their antimicrobial activities against Staphylococcus aureus(ATCC-25923), Enterococcus faecalis} (ATCC-29212), Enterococcus faecalis (ATCC-51922), Listeria monocytogenes (ATCC-1911), Klebsiella pneumoniae (ATCC-700603), Pseudomonas aeruginosa (ATCC-27853), Escherichia coli (ATCC-35218), Escherichia coli (ATCC-25922), Candida albicans (ATCC-90028), Candida glabrata (ATCC-90030), Candida krusei (ATCC-6258), and Candida parapsilosis (ATCC-22019) were investigated. The compounds were also studied for their cytotoxic effects using a MTT assay. Compound 7c showed the highest antimicrobial activity, possessing the same potential as chloramphenicol against K. …

Latest Trends, Green Aspects, And Innovations In Liquid-Phase--Based Microextraction Techniques: A Review, Erkan Yilmaz, Mustafa Soylak

Turkish Journal of Chemistry

Liquid-phase microextraction (LPME) methods including single-drop microextraction (SDME), hollow-fiber LPME (HF-LPME), and dispersive liquid-liquid microextraction (DLLME) have in the very short time since their invention grabbed the attention of scientists. Up to now, LPME methods have shown important innovations for the extraction and preconcentration of both inorganic and organic trace analytes from different matrices. These LPME methods offer unique advantages such as high preconcentration factor for target analytes in a single step, low cost, simplicity, excellent preconcentration capability, sample cleanup and integration of steps, and combined use with almost every analytical measurement technique. We describe the milestones and the combined …

Schiff Base Immobilized Silica Gel Framework As An Efficient Sorbent For Preconcentration Of Pb And Zn Ions In Aqueous Media, Murat Koluman, Feyzullah Tokay, Sema Bağdat

Turkish Journal of Chemistry

A novel preconcentration method for Pb and Zn ions using a column packed with Schiff base modified silica gel is described. The method was based on the sorption of analytes on N,N'-bis(4-methoxysalicylidene)-1,3-propanediamine modified silica gel and elution with HNO$_{3}$ prior to flame atomic absorption analysis. The parameters pH, flow rate, sample volume, eluent volume, and concentration were optimized using a central composite design. The detection limits were 10.0 $\mu $g L$^{-1}$ for Pb and 1.1 $\mu $g L$^{-1}$ for Zn. The suggested procedure was validated with Lake Ontario water as a certified reference material and recovery percentages were 101.8% for …

Preparation Of Fe$_{3}$O$_{4}$ @ Montmorillonite Composite As An Effective Sorbent For The Removal Of Lead And Cadmium From Wastewater Samples, Hande Tinas, Ece Çalişkan, Ni̇l Özbek, Süleyman Akman

Turkish Journal of Chemistry

A magnetic Fe$_{3}$O$_{4}$ @ montmorillonite composite was prepared and used for the separation of lead and cadmium from aqueous solutions. For this purpose, magnetite (Fe$_{3}$O$_{4})$ was generated by co-precipitation of FeSO$_{4}$ and FeCl$_{3}$ onto montmorillonite. The effects of various experimental parameters such as pH of the solution, amount of sorbent, initial concentration of analytes, and contact time on the sorption efficiencies of lead and cadmium ions were investigated and optimized by applying a batch technique. The concentrations of analytes were determined by high resolution continuum source flame atomic absorption spectrometry. The maximum adsorption occurred at pH 2.0. The adsorption capacity …

Electrochemistry-Coupled To Mass Spectrometry In Simulation Of Metabolic Oxidation Of Methimazole: Identification And Characterization Of Metabolites, Kudzanai Chipiso, Reuben H. Simoyi

Chemistry Faculty Publications and Presentations

Methimazole (MMI), an antithyroid drug, is associated with idiosyncratic toxicity. Reactive metabolites resulting from bioactivation of the drug have been implicated in these adverse drug reactions. Mimicry of enzymatic oxidation of MMI was carried out by electrochemically oxidizing MMI using a coulometric flow-through cell equipped with a porous graphite working electrode. The cell was coupled on-line to electrospray ionization mass spectrometry (EC/ESI-MS). ESI spectra were acquired in both negative and positive modes. In acidic medium, ESI spectral analysis showed that the dimer was the main product, while in neutral and basic media, methimazole sulfenic acid, methimazole sulfinic acid and methimazole …