Chemistry Commons^™

Effect Of Acrylic Acid Feed Contents Of Microgels On Catalytic Activity Of Silver Nanoparticles Fabricated Hybrid Microgels, Zahoor Hussain Farooqi, Shanza Rauf Khan, Robina Begum, Farah Kanwal, Ahsan Sharif, Ejaz Ahmed, Shumaila Majeed, Kiran Ejaz, Aysha Ijaz

Turkish Journal of Chemistry

We synthesized poly(N-isopropylacrylamide-co-acrylic acid) microgels with 1, 3, 5, and 7 mol percentage of acrylic acid. Silver nanoparticles were fabricated inside these microgels at room temperature. Pure microgels were characterized by Fourier transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS). Hybrid microgels were characterized by UV-Visible spectroscopy. The size of the silver nanoparticles increased with an increase in the content of acrylic acid. Catalytic activity of these hybrid microgels was investigated using UV-Visible spectrophotometry. Induction time decreased from 8.8 to 2.6 min and the value of apparent rate constant decreased from 0.226 to 0.109 min^{-1}, when the content of …

Resorcinarene-Mono-Benzimidazolium Salts As Nhc Ligands For Suzuki--Miyaura Cross-Couplings Catalysts, Ümi̇t İşci̇, Muhi̇tti̇n Aygün, Resul Sevi̇ncek, Yunus Zorlu, Fabienne Dumoulin

Turkish Journal of Chemistry

Two mono-benzimidazolium salts of resorcinarene have been prepared and used as ligands in Suzuki--Miyaura cross-coupling reactions. They have been fully characterized by $^{1}$H and $^{13}$C NMR, MALDI, and FT-IR spectroscopic methods, and their structures were confirmed by X-ray diffraction analysis. These two new resorcinarene-based mono-benzimidazolium salts showed good catalytic activity for coupling reactions in DMF. The highest conversion was achieved for arylation of 4-bromotoluene using the resorcinarenyl mono-dimethylbenzimidazolium salt.

New Pd(Ii) And Pt(Ii)-Diaminophosphine Complexes Bearing Cyclohexyl Or Isopropyl Moiety: Use Of Pd(Ii) Complexes As Precatalyst In Mizoroki--Heck And Suzuki--Miyaura Cross-Coupling Reactions, Murat Aydemi̇r, Feyyaz Durap, Akin Baysal

Turkish Journal of Chemistry

Two new diaminophosphine ligands, $N$,$N$'-bis(dicyclohexylphosphino)-2-(aminomethyl)aniline (1) and $N$,$N$'-bis(diisopropylphosphino)-2-(aminomethyl)aniline (2) were synthesized by the reaction of 2-(aminomethyl)aniline with two equivalents of Cy$_{2}$PCl or (iPr)$_{2}$PCl, respectively. The reactions of 1 and 2 with MCl$_{2}$(cod) (M = Pd, Pt; cod = 1,5-cyclooctadiene) yield complexes [cis-Pd(L$_{2}$PNHC$_{6}$H$_{4}$CH$_{2}$NHPL$_{2})$Cl$_{2}$] (L = Cy 3, iPr 4) and [cis-Pt(L$_{2}$PNHC$_{6}$H$_{4}$CH$_{2}$NHPL$_{2})$Cl$_{2}$] (L = Cy 5, iPr 6), respectively. The catalytic activity of the palladium complexes was investigated in the Suzuki-Miyaura cross-coupling reaction in the presence of Cs$_{2}$CO$_{3}$ as a base. The palladium complexes were also found to be highly active catalysts in the Mizoroki-Heck reaction.

Substituted 2-(2''-Pyridyl)Benzimidazole Palladium(Ii) Complexes As An Efficient Catalytic System For Suzuki--Miyaura Cross-Coupling Reactions, Mahmut Ulusoy, Nurdal Öncel, Emi̇ne Aytar

Turkish Journal of Chemistry

A new series of $N,N$-type 2-(2'-pyridyl)benzimidazole ligands (2A$_{\mathbf{1}}$, 2A$_{\mathbf{2}}$, 3B$_{\mathbf{1}}$, 3B$_{\mathbf{2}}$, 3B$_{\mathbf{3}}$, and 4C$_{\mathbf{1}})$ and their Pd(II) complexes (5A$_{\mathbf{1}}$, 5A$_{\mathbf{2}}$, 6B$_{\mathbf{1}}$, 6B$_{\mathbf{2}}$, 6B$_{\mathbf{3}}$, and 7C$_{\mathbf{1}})$ were prepared and characterized by conventional spectroscopic methods and elemental analyses. The incorporation of $N$-coordinated benzimidazole complexes of palladium gave high catalytic activity in the Suzuki-Miyaura coupling of aryl halides substrates. After determining the best active catalyst as 5A$_{\mathbf{1}}$, bearing the mesityl substituent on the benzimidazole ring with the Pd(II) ion, optimization studies were carried out via changing the substrate, base, time, atmosphere, and the effect of water. The DMF:H$_{2}$O (4/1) and Cs$_{2}$CO$_{3}$ as base …

The Synthesis Of 1,3-Dialkyl-4-Methylimidazolinium Salts And Their Application In Palladium Catalyzed Heck Coupling Reactions, Murat Yi̇ği̇t, Güli̇n Bayam, Beyhan Yi̇ği̇t, İsmai̇l Özdemi̇r

Turkish Journal of Chemistry

Seven novel 1,3-dialkyl-4-methylimidazolinium chloride salts 3a--g were prepared as precursors of N-heterocyclic carbenes by reacting N,N'-alkyl-1,2-diaminopropane, triethyl orthoformate, and ammonium chloride. The salts were characterized spectroscopically. The in situ prepared palladium complexes derived from the imidazolinium salts and palladium acetate were used as catalyst in Heck coupling reactions between aryl bromides and styrene. The corresponding Heck products were obtained in good yields.

Redox Polymerization Of N-Isopropylacrylamide By Using Hydroxylated Soya Oil Polymer, Abdulkadi̇r Alli, Ti̇mur Şanal, Baki̇ Hazer

Turkish Journal of Chemistry

Water soluble hydroxylated soya oil polymer was used in the redox polymerization of N-isopropylacrylamide (NIPAM) in order to obtain water-based hydroxylated-soya oil polymer-g-PNIPAM graft copolymer. For this purpose, soya oil was exposed to air under sunlight to obtain autoxidized soya oil polymer (PSy-ox). PSy-ox was allowed to react with diethanol amine to obtain hydroxylated soya oil polymer (hydroxylated-PSy). An ammonium persulfate with hydroxylated-PSy redox initiating system was used in the polymerization of NIPAM in order to obtain thermo-responsive hydroxylated-PSy-g-PNIPAM water-based graft copolymers. The graft copolymers were characterized using proton nuclear magnetic resonance, Fourier transform infrared~spectroscopy, gel permeation chromatography, thermal gravimetric …

Synthesis, Characterization, Biological Studies, And Molecular Modeling Of Mixed Ligand Bivalent Metal Complexes Of Schiff Bases Based On $N$-Aminopyrimidine-2-One/2-Thione, Hati̇ce Gamze Soğukömeroğullari, Tuğba Taşkin Tok, Feyza Yilmaz, İsmet Berber, Mehmet Sönmez

Turkish Journal of Chemistry

New mixed Schiff bases, Cu(II), Co(II), Ni(II), and Mn(II) complexes, were synthesized derived from 5-chloro-2-hydroxyacethophenone and 1-amino-5-benzoyl-4-phenyl-1H-pyrimidine-2-one/thione. These complexes were characterized by elemental analysis, magnetic measurements, molar conductivity, IR, electronic, NMR, and mass spectral studies. All the complexes showed nonelectrolytic behavior. Moreover, the newly synthesized mixed ligand complexes were evaluated for their in vitro antimicrobial efficiency against bacteria and yeast. The compound named Co(L$_{1}$L) had good antifungal activity against Candida species, but no profound antibacterial effect against bacterial strains. In addition, the ground state geometries of the complexes were optimized using a semi-empirical method at PM6 level, which is a …

Simultaneous Analysis Of Losartan, Its Active Metabolite, And Hydrochlorothiazide In Human Plasma By A Uplc-Ms/Ms Method, Priyanka A. Shah, Primal Sharma, Jaivik V. Shah, Mallika Sanyal, Pranav S. Shrivastav

Turkish Journal of Chemistry

A selective and sensitive ultra performance liquid chromatography-tandem mass spectrometry method was developed for the simultaneous determination of losartan (LOS), EXP-3174, which is an active metabolite LOS carboxylic acid, and hydrochlorothiazide (HCTZ) in human plasma. Solid-phase extraction was carried out on Oasis HLB cartridges with 100 $\mu $L of plasma to give an extraction recovery in the range of 88.5%-102.5% for the three analytes. Chromatography on a BEH C18 column afforded baseline separation of all the analytes within 2.4 min using 1.0% formic acid in water and acetonitrile (15:85, v/v) as the mobile phase. Quantitation was performed with multiple reaction …

Synthesis Of Novel 1,2,4-Triazoles And Triazolo-Thiadiazines As Anticancer Agents, Thoraya Abd El-Reheem Farghaly, Magda Ahmad Abdallah, Huda Kamel Mmahmoud

Turkish Journal of Chemistry

A new series of 7-arylazo-5$H$-3-(trifluoromethyl)-6-methyl-1,2,4-triazolo-[3,4-$b$]-1,3,4-thiadiazines was prepared by reaction of 4-amino-3-trifluoromethyl-5-mercapto-1,2,4-triazoles with $N$-aryl-2-oxo-propane hydrazonoyl chloride in dioxane under reflux in the presence of triethylamine. Furthermore, Schiff bases of 4-amino-5-mercapto-1,2,4-triazole derivatives were reacted with a variety of hydrazonoyl chlorides and gave the respective hydrazonothioates. In addition, the novel \textit{bis}-(1,2,4-triazole-3-thione) was reacted with the appropriate hydrazonoyl chloride in dioxane under reflux in the presence of triethylamine to give the corresponding \textit{bis}-(1,2,4-triazolethiohydrazonoate). The structures of the new compounds were established based on elemental and spectral data. The mechanism of the studied reaction was also discussed. Moreover, some of the new products were screened …

Thermogravimetric Analysis-Based Screening Of Metal (Ii) Chlorides As Dopants For The Destabilization Of Solid-State Hydrazine Borane, Weiguang Chen, Umit Bilge Demirci

Turkish Journal of Chemistry

Thermogravimetric analysis (TGA) is a powerful technique for screening boranes envisaged for chemical hydrogen storage. The demonstration is based on the use of six metal (II) chlorides (MCl$_{2})$ (with M as 3d-metal or d$^{8}$-metal) as destabilizing agents of solid-state hydrazine borane (N$_{2}$H$_{4}$BH$_{3})$. On the basis of TGA profiles combined with derivative thermogravimetric (DTG) curves, it is shown that: e.g. (1) CuCl$_{2}$ is an inefficient dopant whereas it is efficient towards ammonia borane (NH$_{3}$BH$_{3})$; (2) one of the best destabilization results is achieved with N$_{2}$H$_{4}$BH$_{3}$ doped by 10 wt{\%} CuCl$_{2}$-NiCl$_{2}$, the sample decomposing from 30 $^{\circ}$C with greatly mitigated amounts of …

Synthetic Oligodeoxynucleotide Purification Via Catching By Polymerization, Suntara Fueangfung

Dissertations, Master's Theses and Master's Reports - Open

Large quantities of pure synthetic oligodeoxynucleotides (ODNs) are important for preclinical research, drug development, and biological studies. These ODNs are synthesized on an automated synthesizer. It is inevitable that the crude ODN product contains failure sequences which are not easily removed because they have the same properties as the full length ODNs. Current ODN purification methods such as polyacrylamide gel electrophoresis (PAGE), reversed-phase high performance liquid chromatography (RP HPLC), anion exchange HPLC, and affinity purification can remove those impurities. However, they are not suitable for large scale purification due to the expensive aspects associated with instrumentation, solvent demand, and high …

Design And Development Of Bodipy-Based Fluorescent Probes For Sensing And Imaging Of Cyanide, Zn (Ii) Ions, Lysosomal Ph And Cancer Cells, Jingtuo Zhang

Dissertations, Master's Theses and Master's Reports - Open

BODIPY (4,4-Difluoro-3a,4a-diaza-s-indacene) dyes have gained lots of attention in application of fluorescence sensing and imaging in recent years because they possess many distinctive and desirable properties such as high extinction coefficient, narrow absorption and emission bands, high quantum yield and low photobleaching effect. However, most of BODIPY-based fluorescent probes have very poor solubilities in aqueous solution, emit less than 650 nm fluorescence that can cause cell and tissue photodamages compared with bio-desirable near infrared (650-900 nm) light. These undesirable properties extremely limit the applications of BODIPY-based fluorescent probes in sensing and imaging applications. In order to overcome these drawbacks, we …

Multi-Mode And Single Mode Polymer Waveguides And Structures For Short-Haul Optical Interconnects, Kevin L. Kruse

Dissertations, Master's Theses and Master's Reports - Open

Single mode and multi-mode polymer optical waveguides are a viable solution for replacing copper interconnects as high speed and large bandwidth short-haul optical interconnects in next-generation supercomputers and data servers. A precision laser direct writing method is implemented for producing various single mode and multi-mode polymer waveguide structures and their performance is evaluated experimentally showing agreement with theoretically developed models. The laser direct writing method is the optimal solution for low-rate cost-effective prototyping and large area panel production.

A single mode polymer waveguide bridge module for silicon to glass optical fibers is designed, modeled, fabricated, and measured. The bridge module …

On The Protective Properties Of Glycine Based Osmolytes In A Thiol Reducing Environment, John Michael Hausman

Dissertations, Master's Theses and Master's Reports - Open

The protective properties of osmolytes have been studied intently for decades. Originally used to aid in the crystallization of proteins in x-ray diffraction studies, these cosolvents have been shown to reverse protein denaturation and aggregation. Osmolytes aid extremophiles in surviving harsh environments by preferentially excluding themselves from the surface of the protein, thus directing water molecules to the protein’s surface. These osmolytes are naturally found in many health foods and also in many daily use products such as shampoo. Due to their osmoprotective effect their use in everyday consumer product is increasing. Consumers also supplement their diets with thiol-based antioxidants …

Characterization Of Transport And Transformation Of Air Pollutants Observed In The Free Troposphere Over The Central North Atlantic, Bo Zhang

Dissertations, Master's Theses and Master's Reports - Open

Long-range transport of continental pollution emissions has been found to affect air quality in the downwind regions. The Pico Mountain Observatory (PMO), which was established in 2001 in the Azores Islands, has been a perfect site to study long range transport from North America to the central North Atlantic. The dissertation uses the observations and modeling products created since 2001 to provide insights on ozone production tendency during transport, trace gases observations for varying transport patterns, and aerosol ages in the free troposphere over the central North Atlantic.

The first phase of this dissertation research focused on determining the causes …

A Computational Comparison Of The Hydrophobic Pocket Of Neural And Epithelial Cadherins For The Purpose Of Identifying A Selective Inhibitor, Ross E. Straughan

Honors Theses

Classical cadherins are a subfamily of calcium-dependent cellular adhesion molecules that play an important role in the formation of cellular junctions in many tissues. The extracellular portion of cadherins consists of five tandem-repeated domains (EC1-EC5). The critical first step in cadherin-mediated cellular adhesion occurs at the interface between two adjacent EC1 domains in which the transition from monomer to dimer is accomplished by docking the W2 residue of the N-terminal β-strand of one EC1 domain into the hydrophobic pocket of its partner domain. Cancer and many other diseases have been linked to the aberrant expression of Epithelial (E-cad) and Neural …

Effect Of Biochar And Activated Carbon Amendments On Gaseous Mercury Emissions Of Soil And Mercury Methylation Rates In Sediment, Ryan Sessums

Honors Theses

Mercury is a pervasive global contaminant with a complex biogeochemical cycle. In this biogeochemical cycle, methylmercury (MeHg+) tends to biomagnify and concentrate in fish and seafood consumed by humans. This study examines the effect of sorbent amendments on both the mercury emission from soils and the methylation rates of mercury in sediments, both of which are believed to be major contributors to the global cycle. Biochar and activated carbon were used to treat soils and sediments to explore their effects. It was found that biochar and activated carbon reduced gaseous mercury emission by 25% and 49%, respectively. Methylation rates in …

The Effect Of Polyamines On I-Motif Thermal Stablity, Shelby Claire Liddell

Honors Theses

Polyamines are present inside cells at varying concentrations anywhere between 10 mM and 60 mM, and because of their molecular structure they contribute a positive charge to the interior of the cell. There has been previous evidence that the concentrations of polyamines have an effect on the stability of the DNA strands, which can affect the cellular processes. The particular DNA conformation studied is the i-motif, which is formed by intermolecular folding in cytosine rich strands. The i-motif studied is C20T, which is found in the promoter region of the oncogene, c-myc. Stabilization of c-myc can have an effect on …

Dna I-Motif Stabilization By Ligand Binding To Loop Regions, Harrison Reed Davis

Honors Theses

DNA i-motifs are a secondary structure of DNA that can be useful in a variety of ways, but this experiment investigates the maximum potential to stabilize i-motifs artificially with a small molecule binding to loop regions. DNA with different position and number of loops was tested to see to what extent the i-motif could be stabilized . A drug, Actinomycin D, was used for its known high affinity for a particular DNA sequence, which we used to make the loops of the i-motif. The binding constant for the drug to the DNA was determined through fluorescense spectroscopy while the presence …

Method Development For The Detection And Quantitation Of Illicit Drugs In Fingerprints Using Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry, Madison Roussel

Honors Theses

The purpose of this research was to develop a method for the detection and quantitation of caffeine and 11-nor-9-carboxy-Δ9- tetrahydrocannabinol in fingerprints using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). The matrix used was 2,5-dihydroxybenzoic acid (DHB). The presence of the analytes was confirmed by analysis using liquid chromatography-mass spectrometry (LC-MS). 11-nor-9-carboxy-Δ9- tetrahydrocannabinol was chosen as the drug of interest because it is the major metabolite of tetrahydrocannabinol, the main psychoactive component of marijuana. Marijuana's popularity as a recreational drug continues to increase with its legalization and decriminalization across the country. It is critical to establish methods for the quantification …

X-Dimer Mutations And Their Effects On The Folding Stability And Assembly Of Ecad12 At The K14-D138 Interface, Martha Kaitlyn Coghlan

Honors Theses

Classical cadherins were first identified by their function in mediating calcium-dependent cellular adhesion and constitute a large family of cellular adhesion receptor proteins whose differential binding is central to the development and maintenance of tissue architecture. The interface underlying the binding interaction reveals that all classical cadherins share a common adhesive interface in which the portion of the β-A strand closest to the N-terminus is swapped between EC1 domains of the adhesive partner protomers. A second dimeric configuration, known as the 'X-dimer', is the face-to-face association of two protomers in which their orientation is dictated by three symmetrical noncovalent interactions …

From Lazarus To Theophilus: How Manuscript Digitization Led To The Historical, Chemical, And Technological Understanding Of Iron Gall Ink And Its Counterparts, Meredith Oliver

Honors Theses

This paper examines the physical and chemical composition of iron gall ink, how such composition has changed throughout its use in history, and the current chemical, digital, and multi-spectral methods by which the digital humanities use to preserve ancient texts inscribed with such ink. By using spectral technology, I hypothesized it possible to date and locate the geographic origin of ink based on its chemical composition. Uv-vis, fluorescence, and micro-XRF spectrometry were used to analyze elemental composition. Ink samples were made to simulate the ink on ancient manuscripts for UV-vis and fluorescence spectral analysis. Micro-XRF was performed on the Vercelli …

Characterization Of Epithelial Cadherin Domain 1, Molly Edmondson

Honors Theses

Cadherins are a family of cell-surface glycoproteins that aid in cell adhesion between two proximal cells. The characteristic cadherin extracellular structure consists of five ~100 amino acid domains connected by seven-residue linker regions. Cadherins mediate adhesion via adherens junctions by forming a strand-swapped structure between identical protomers from apposing cells. Upon calcium binding, the swapping of the N- terminal strands between protomers allows for the symmetrical docking of a conserved tryptophan residue in the N-terminal strand into the hydrophobic pocket of its partner protomer. The two most-well-studied members of the classical cadherin family are Neural- (N-) and Epithelial- (E-) cadherin. …

A Raman Spectroscopic And Computational Study Of The Effects Of Halogen Bonding On Pyrimidine Containing Systems, Peyton Lindsey Reves

Honors Theses

This thesis involves the study of the effects of halogen bonding on pyrimidine containing systems. Halogen bonding is a type of non-covalent interaction that can occur when a Lewis base interacts with an iodine, bromine, or chlorine atom in a second molecule. The phenomenon of halogen bonding is explained by the presence of a localized region of positive electrostatic potential that exists on the halogen. This positive region is referred to as the σ-hole, and gives halogen bonding its other common name, σ-hole bonding. The magnitude of the positive σ-hole depends on both the type of halogen molecule involved in …

Development Of An In-Field Voltammetric Method For The Determination Of Barium, Samantha N. Ridgway

Theses : Honours

This work presents a reliable, cost-effective, rapid and infield voltammetric method for the detection of barium. The optimized method consists of an ultrathin mercury film deposited in-situ on a glassy carbon electrode in 0.02 M potassium chloride without deoxygenation; a deposition potential of -2500 mV, pulse height = 50 mV, step duration = 10 ms and a scan rate of 100 mV/s using differential pulse anodic stripping voltammetry (DP-ASV).

The linear working range for barium was determined to be 5 – 80 μg/L (r² = 0.997), and limit of detection (LOD) was 1.6 μg/L, for 30 sec deposition time. …

Investigation Of Solvent-Dependent Properties Of Donor And Acceptor Materials For Photovoltaic Applications, Anna L. Foote

Browse all Theses and Dissertations

The choice of solvent and additive has been shown to affect efficiency of organic solar cell devices. To gain a basic understanding of the role of solvents in influencing overall device performance, we present a comparative study on the physical properties of donor: acceptor mixtures in different solvents. Investigations have been carried out for P3HT (poly(3-hexylthiophene-2,5-diyl)), PTB7 (poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']-dithiophene-2,6-diyl][3-fluro-2-[2-ethylhexyl)carbonyl[thieno[3,4-b]thiophenediyl]]), PC61BM ([6,6]-phenyl-C60-butyric acid methyl ester), and PC71BM ([6,6]-phenyl-C70-butyric acid methyl ester). The physical properties reported are based on UV-Vis absorption spectroscopy, resistance measurements, cyclic voltammetry measurements, and surface energy characterizations of the organic films. The solvents used to prepare the organic films …

Method Development For Mass Spectrometric Characterization Of Ultra-Small Nanomolecules And Mass Spectrometry Imaging Of Selected Biomolecules, Nuwan K. Kothalawala

Electronic Theses and Dissertations

High sensitivity, selectivity and remarkable identification capabilities facilitate the applicability of mass spectrometry (MS) in diverse fields. This dissertation outlines how this cutting edge technology is used to determine the chemical composition of the ultra-small nanomolecules (NMs) to atomic precision and obtain spatial resolution of selected biomolecules using mass spectrometry imaging (MSI). Chapter I includes introduction to electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) MS used in my PhD research. Chapter II explains how high resolution ESI-MS methods were developed to analyze the polar water-soluble NMs. These new methods express how ESI-MS parameters need to be optimized …

Effective Tuning Of Bimetallic Composition Of Gold-Copper Nanomolecules And The Emergence Of Plasmon-Like Feature In Optical Spectra, Asantha Champika Dharmaratne

Electronic Theses and Dissertations

Au144-xCux(SR)60 alloy nanomolecules were synthesized and characterized by using ESI-MS to atomic precision. A maximum of 23 copper atoms replace the gold atoms; when the number of copper atoms is higher than eight, a surface plasmon-like peak appears at ∼520 nm. Based on the fundamental, elemental properties of Au and Cu, we predict a mixed atomic ordering and incorporation into the Au12 and Au 42 shells of the proposed icosahedral structured model. Alloy nanomolecules reported here could have potential applications in the field of catalysis and optical sensors.

Mass Spectral Studies To Investigate Butylbenzene Fragmentation Pathway And Pyrolysis Products., Balasubramaniam Lingam

Electronic Theses and Dissertations

In this dissertation research, two fundamental studies involving gas chromatography mass spectrometry of n-butylbenzene and pyrolysis products are presented. In the first study, fragmentation pathways of n-butylbenzene in quadrupole ion trap have been investigated. At low energy, product ion corresponding to m/z 92 and m/z 91 are formed via competitive parallel dissociation. Studies have also shown that at higher energy m/z 92 has sufficient internal energy to undergo further fragmentation yielding m/z 91 via consecutive dissociation. Thus in order to discern the fragmentation pathways of n-butylbenzene, the technique of two-dimensional correlation spectroscopy (2DCOS) was applied to the mass spectral data. …

Development Of A Nano-Sensing Approach And A Portable Prototype For Real-Time Detection And Quantification Of Free Mercury In Stream-Flow: Combining Science And Engineering In Pro Of The Environment, Warinya Chemnasiri

Electronic Theses and Dissertations

Mercury (Hg) is a well-known hazardous environmental contaminant existing in several forms, but all are toxic to human in one way or the others. Since Hg usually settles into water polluting the environment and accumulating in living organisms, it is crucial to monitor Hg levels in the aquatic ecosystem. Although there are many well established techniques currently used to detect Hg, most of them require elaborate and time-consuming sample preparation and pre-concentration procedures, as well as costly and bulky equipment that limit their practical application in the field. In order to overcome the existent limitations in Hg determination methods, Hernandez …