Lc-Ms/Ms Method Development And Analysis Of Tricyclic Antidepressants In Human Plasma,
2021
University of Mississippi
Lc-Ms/Ms Method Development And Analysis Of Tricyclic Antidepressants In Human Plasma, Shahbaz Gul
Honors Theses
Depression has become one of the most prominent problems in society, disrupting both personal and social lives. Tricyclic antidepressants (TCAs) were first developed in the 1950’s and became some of the leading anti-depressant medications on the market later that decade. Today, newer anti-depressants have risen to the forefront, being safer and having a lower side-effect probability. Nonetheless, TCAs continue to be prescribed for severe depression, especially in cases where the newer anti-depressants have failed. However, TCAs are still highly potent, the toxicity associated with these compounds cannot be ignored. They have considerable cardiovascular and neurological toxicity, and in the event …
Determination Of Metals In Whey And Vegan Protein Supplements Using Inductively Coupled Plasma Mass Spectrometry,
2021
University of Mississippi
Determination Of Metals In Whey And Vegan Protein Supplements Using Inductively Coupled Plasma Mass Spectrometry, Megan Lofaso
Honors Theses
Driven by a demand for health and wellness products worldwide, the dietary supplement industry continues to expand with an economic impact >$100 billion in the USA alone. However, the industry is plagued by a lack of regulation and incidents of contamination, including with toxic heavy metals that can put consumers at potential risk. In this study, eight trace elements (Cd, Pb, Fe, Co, Mn, V, Cu, and Cr), including heavy metals (Cd and Pb), were determined in whey and vegan protein powder by inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted digestion using nitric acid and hydrogen peroxide. Samples were …
Electrochemical Oxidation Of Individual Silver Nanoparticles: Exploring The Effect Of Particle Shape, Capping Ligand, Electrolyte, And Potential On The Signal,
2021
University of Arkansas, Fayetteville
Electrochemical Oxidation Of Individual Silver Nanoparticles: Exploring The Effect Of Particle Shape, Capping Ligand, Electrolyte, And Potential On The Signal, Jazlynn Sikes
Graduate Theses and Dissertations
Nanomaterials have revolutionized science and technology. Their unique properties can be exploited, and nanoparticles are being used as catalysts, antimicrobials, drug delivery vehicles, sensors, and more. However, the fundamental properties of nanomaterials and their interactions with their surrounding environments are still poorly understood. In this work, a single-particle approach was used to observe the effects of capping ligand, surrounding solution, and particle shape on the oxidative process to gain deeper understanding of silver nanoparticle properties. When allowed the opportunity, the particles will adsorb to the electrode surface then oxidize in rapid succession upon electrode activation, regardless of capping ligand as …
A Conductivity Analysis Of A Newly Synthesized Poly(Ethylene Glycol) Methyl Ether Hydroxide Electrolyte,
2021
University of Mississippi
A Conductivity Analysis Of A Newly Synthesized Poly(Ethylene Glycol) Methyl Ether Hydroxide Electrolyte, Sarah Marie Peterson
Honors Theses
This thesis investigates the synthesis and conductive properties of a Poly (ethylene glycol) methyl ether-based polymer electrolyte. The goal of the synthesis is to enhance the hydroxide ion conduction properties of the polymer with its cationic groups attached. The MePEG backbone contained seven ethylene glycol groups and was modified to substitute the hydroxide group in the MePEG with trimethylamine. In addition, the bromide added in the synthesis was exchanged for hydroxide ions to allow for the transportation of hydroxide ions in polymeric electrolytes that can be used in Anion Exchange Membrane Fuel Cells. The newly synthesized polymer was compared to …
New Applications For The Kinetic Exclusion Assay (Kinexa),
2021
Boise State University
New Applications For The Kinetic Exclusion Assay (Kinexa), Mark Harrison Smith
Boise State University Theses and Dissertations
This dissertation examines the fundamental principles and applicability of the kinetic exclusion assay (KinExA), developed and marketed by Sapidyne Instruments of Boise, Idaho, since 1995. Chapter One reviews and consolidates the manufacturer’s guidance and many early papers that delineate the practical and theoretical aspects of the technology. In brief, KinExA is a two stage analytical system. In stage one, a number of solutions are prepared, whereby one of the partners is kept constant (the constant binding partner, or CBP), while the other (the titrant) is varied, usually in serial dilution. As the titrant is increased, the free CBP decreases, and …
Luminol/Sulfamic Acid Electrochemiluminescence And Its Application For Dopamine Detection,
2021
1. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, Jilin,China; 2. School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, Anhui, China; 3. Wolkite University, College of Natural & Computational Science, Department of Chemistry, P.O Box 07, Wolkite, Ethiopia
Luminol/Sulfamic Acid Electrochemiluminescence And Its Application For Dopamine Detection, Tesfaye Hailemariam Barkae, Mohamed Ibrahim Halawa, Tadesse Haile Fereja, Shimeles Addisu Kitte, Xian-Gui Ma, Ye-Quan Chen, Guo-Bao Xu
Journal of Electrochemistry
Herein, sulfamic acid (SA) was utilized, for the first time, to enhance significantly the luminol electrochemiluminescence (ECL). With the SA concentration increased from 0.1 μmol·L-1 to 500 μmol·L-1 the ECL intensity increased proportionally. The developed luminol/SA ECL system was employed to detect dopamine (DA) based on its prominent quenching effect. The Stern-Volmer equation of Io/I= 1+Ksv[DA] could be applied to express well the quenching mechanism of DA in the luminol/SA ECL system. The calibration plot showed that the increase in the DA concentration from 0.5 to 20 μmol·L-1 decreased linearly the ECL intensity …
Electrochemical Surface-Enhanced Raman Spectroscopic Studies On Nickel Ultramicroelectrode,
2021
1. School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China;
Electrochemical Surface-Enhanced Raman Spectroscopic Studies On Nickel Ultramicroelectrode, Li-Wen Wu, Wei Wang, Yi-Fan Huang
Journal of Electrochemistry
Nickel (Ni) electrodes are widely used in electrochemical researches. Understanding electrochemical processes on Ni electrodes through in-situ characterization of adsorbed species on their surfaces is helpful for rational optimization and application of Ni electrochemistry. Microelectrochemical surface-enhanced Raman spectroscopy (μEC-SERS) combines the mass transfer feature of ultramicroelectrode with high-sensitivity characterizations of molecular structures, which is a powerful method for studying Ni electrochemistry on polarization and non-equilibrium conditions. The key point of performing μEC-SERS is to make a SERS-active Ni ultramicroelectrode.
Here, we demonstrate a method of preparing a SERS-active Ni ultramicroelectrode through electrochemical deposition of several atomic layers of …
Electrochemical Gating Single-Molecule Circuits With Parallel Paths,
2021
1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China;
Electrochemical Gating Single-Molecule Circuits With Parallel Paths, Jun-Qing Su, Yi-Fan Zhou, Ling Tong, Ya-Hao Wang, Ju-Fang Zheng, Jing-Zhe Chen, Xiao-Shun Zhou
Journal of Electrochemistry
Electrochemical gating has emerged as a feasible and powerful method to tune single-molecule conductance. Herein, we demonstrate that the electron transport through single-molecule circuits with two benzene rings in parallel could be efficiently gated by electrochemistry. The molecular junctions with two parallel paths are fabricated with Au electrodes by STM break junction (STM-BJ) technique. Their conductance value exhibits a 2.82-fold enhancement by the constructive quantum interference compared to single-molecule junctions with single path for electron tunneling. Furthermore, the conductance of para-benzene based molecule could be electrochemically tuned with a modulation ratio of about 333%·V-1. With the help of …
Structure Formation And Coupling Reactions Of
Hexaphenylbenzene And Its Brominated Analog,
2021
University of Nebraska – Lincoln
Structure Formation And Coupling Reactions Of Hexaphenylbenzene And Its Brominated Analog, Jacob D. Teeter, Paulo S. Costa, Christoph Dobner, Mamun Sarker, Alexander Sinitskii, A Enders
Department of Chemistry: Faculty Publications
The on-surface coupling of the prototypical precursor molecule for graphene nanoribbon synthesis, 6,11-dibromo-1,2,3,4-tetraphenyltriphenylene (C42Br2H26, TPTP), and its non-brominated analog hexaphenylbenzene (C42H30, HPB), was investigated on coinage metal substrates as a function of thermal treatment. For HPB, which forms non-covalent 2D monolayers at room temperature, a thermally induced transition of the monolayer’s structure could be achieved by moderate annealing, which is likely driven by π-bond formation. It is found that the dibrominated carbon positions of TPTP do not guide the coupling if the growth occurs on a substrate at temperatures that …
Experimental And Theoretical Investigation Of Regioselectivity For A Series Of Ketoimines With Nuclear Magnetic Resonance Spectroscopy And Density Functional Theory,
2021
Pepperdine University
Experimental And Theoretical Investigation Of Regioselectivity For A Series Of Ketoimines With Nuclear Magnetic Resonance Spectroscopy And Density Functional Theory, Amanda Stahl, Joseph M. Fritsch, Kelsey R. Brereton
Seaver College Research And Scholarly Achievement Symposium
A series of ketoimines bearing pendant quinolyl substituents were prepared by Schiff base condensation of 1,3-diketones with two different substituents: trifluoromethyl and an alkyl/aryl group (e.g., Me, Et, iPr,tBu, Ph. Synthetic reactions of ketoimines with varying alkyl/aryl substituents altered the distribution of regioisomers as measured in isolated yields and detected by 1H and 19F NMR spectroscopy of crude reaction mixtures. Reaction with the least sterically encumbered diketone (CF3with Me) resulted in mixture of ketoimines with virtually quantitative formation of the ketoimine resulting from quinolyl addition to the carbonyl adjacent to the alkyl substituent. …
Nitro Group Reduction For Use In Organic, Cathodic Materials,
2021
University of South Dakota
Nitro Group Reduction For Use In Organic, Cathodic Materials, Brock G. Goeden
Honors Thesis
The industrial demand for higher capacity, light-weight battery materials has skyrocketed in recent years due to heavy investments in portable electronics, electronic vehicles, and renewable energy sources. However, rechargeable battery technology has seen little improvement since the invention of the Lithium-Ion battery in the 1980s. The low energy density of the traditionally utilized LiCoO2 cathodic material (specific capacity: 272 mAh g-1), has limited its potential to meet these increasing demands. To solve this problem, our research group is investigating new types of lightweight, organic, polymeric materials with conductive backbones as a possible replacement for the cathodic materials in Lithium-Ion batteries. …
Development Of A Rapid Drug Detection Method For Insects Using Paper Spray Ionization Mass Spectrometry (Psi-Ms),
2021
Duquesne University
Development Of A Rapid Drug Detection Method For Insects Using Paper Spray Ionization Mass Spectrometry (Psi-Ms), Alexandria Plyler
Undergraduate Research and Scholarship Symposium
Insects have the ability to reflect the chemical environment that they have developed in. Thus, necrogenous insects can reflect the chemical environment of cadavers they have fed on. Forensic scientists can potentially utilize insect larvae as an alternate biological matrix to detect drugs in cadavers that are skeletonized, burned, or otherwise badly damaged. Analysis of insects using paper spray ionization mass spectrometry (PSI-MS), an analytical method requiring little to no sample preparation, could prove a rapid, cost-effective, and non-destructive alternative form of toxicological analysis. Traditional tissue analysis via GC and LC-MS often require lengthy sample preparation, use expensive reagents, and …
Theoretical Investigation Of In2h2 And Tl2h2 And Their Relationship To Other Group 13 Metal Dihydrides,
2021
Wofford College
Theoretical Investigation Of In2h2 And Tl2h2 And Their Relationship To Other Group 13 Metal Dihydrides, Caroline Sargent
Student Scholarship
Four constitutional isomers{ dibridged, monobridged, vinylidene-like, and trans{ of group 13 metal dihydrides have been reviewed and studied by theoretical methods. Equilibirum structures, relative enthalpies, and vibrational spectroscopic information is presented for isomers of Al2H2, Ga2H2, In2H2, and Tl2H2. Properties of the isomers of Al2H2 and Ga2H2 were obtained from previous studies.1{3 Properties of In2H2 and Tl2H2 were calculated using rigorous ab initio theory, and the results are presented. …
Imaging Of Neurotransmitters And Small Molecules In Brain Tissues Using Laser Desorption/Ionization Mass Spectrometry Assisted With Zinc Oxide Nanoparticles.,
2021
Western University
Imaging Of Neurotransmitters And Small Molecules In Brain Tissues Using Laser Desorption/Ionization Mass Spectrometry Assisted With Zinc Oxide Nanoparticles., Chaochao Chen, Steven R Laviolette, Shawn N Whitehead, Justin B Renaud, Ken K-C Yeung
Chemistry Publications
Inorganic nanostructured materials such as silicon, carbon, metals, and metal oxides have been explored as matrices of low-background signals to assist the laser desorption/ionization (LDI) mass spectrometric (MS) analysis of small molecules, but their applications for imaging of small molecules in biological tissues remain limited in the literature. Titanium dioxide is one of the known nanoparticles (NP) that can effectively assist LDI MS imaging of low molecular weight molecules (LMWM). TiO2 NP is commercially available as dispersions, which can be applied using a chemical solution sprayer. However, aggregation of NP can occur in the dispersions and the aggregated NP …
Determination Of Atrazine In Glacier Creek Using Gas Chromatography-Mass Spectrometry,
2021
University of Nebraska at Omaha
Determination Of Atrazine In Glacier Creek Using Gas Chromatography-Mass Spectrometry, Spencer Witte
UNO Student Research and Creative Activity Fair
Atrazine is a commonly used herbicide in agriculture that has been shown to cause adverse health-effects on biological organisms. Glacier Creek Preserve (GCP), a prairie preserve near Omaha, NE, contains restored prairie and agricultural land uses within a single watershed. Surface water samples were collected at various locations of GCP from May to July to quantify atrazine concentrations. Sample preparation included filtering with a 0.45 micron filter and solid-phase extraction (SPE) with a reversed-phase cartridge. The analyte was eluted off the cartridge with ethyl acetate and analyzed by gas chromatography-mass spectrometry (GC/MS). Quantitation was performed with an internal standard calibration …
Molecular Design Of Three-Dimensional Metal-Free A(Nh4)X3
Perovskites For Photovoltaic Applications,
2021
Nanjing University
Molecular Design Of Three-Dimensional Metal-Free A(Nh4)X3 Perovskites For Photovoltaic Applications, Jie Bie, Dai-Bei Yang, Ming-Gang Ju, Qiang Pan, Yu-Meng You, Wei Fa, Xiao Cheng Zeng, Shuang Chen
Xiao Cheng Zeng Publications
The intense research activities on the hybrid organic−inorganic perovskites (HOIPs) have led to the greatly improved light absorbers for solar cells with high power conversion efficiency (PCE). However, it is still challenging to find an alternative lead-free perovskite to replace the organohalide lead perovskites to achieve high PCE. This is because both previous experimental and theoretical investigations have shown that the Pb2+ cations play a dominating role in contributing the desirable frontier electronic bands of the HOIPs for light absorbing. Recent advances in the chemical synthesis of three-dimensional (3D) metal-free perovskites, by replacing Pb2+ with NH4+ …
A Systematic Multiscale Investigation Of Nanoparticle-Assisted Co2 Enhanced Oil Recovery (Eor) Process For Shale Oil Reservoirs,
2021
Louisiana State University and Agricultural and Mechanical College
A Systematic Multiscale Investigation Of Nanoparticle-Assisted Co2 Enhanced Oil Recovery (Eor) Process For Shale Oil Reservoirs, Dayo A. Afekare
LSU Doctoral Dissertations
Shale oil reservoirs are prolific on the short term due to hydraulic fracturing and horizontal drilling but experience significant production decline, leading to poor ultimate recovery and leaving billions of barrels of oil buried in the ground. In this study, a systematic multi-scale investigation of an enhanced oil recovery (EOR) process using relatively inexpensive silicon dioxide nanoparticles and carbon dioxide for shale oil reservoirs was conducted. Using the Tuscaloosa Marine Shale (TMS) as a case study, aqueous dispersions of nanosilica in conjunction with CO2 were investigated at nano-to-core scales. At the nanoscale, atomic force microscope was used to investigate …
Investigations Of The Structure And Protein-Protein Interactions Of Chlamydia Trachomatis Scc4,
2021
Louisiana State University and Agricultural and Mechanical College
Investigations Of The Structure And Protein-Protein Interactions Of Chlamydia Trachomatis Scc4, Thilini Oshadhi Senarath Ukwaththage
LSU Doctoral Dissertations
Chlamydia trachomatis (CT) is the most common, sexually transmitted bacterial disease (STD) in the world. In the developmental cycle of CT, specific chlamydia chaperone 4 (Scc4) is a unique protein with essential and multiple roles. Hence, Scc4 is significant as a virulence target for therapeutic approaches to treat chlamydial infections. A novel approach was discovered to purify tag free Scc4 by utilizing a 6X-histidine-tag on Scc1 in the co-expressed Scc4:Scc1 complex by capturing the complex on nickel-charged immobilized metal affinity chromatography resin, followed by dissociation of Scc4 with sarkosyl. Using triple resonance NMR experiments, backbone and sidechain resonances …
Three-Way Analysis-Based Ph-Uv-Vis Spectroscopy For Quantifying Allura Red In An Energy Drink And Determining Colorant's Pka,
2021
Ankara University
Three-Way Analysis-Based Ph-Uv-Vis Spectroscopy For Quantifying Allura Red In An Energy Drink And Determining Colorant's Pka, Erdal Dinç Prof., Nazangül Ünal, Zehra Ceren Ertekin
Journal of Food and Drug Analysis
Three-way analysis-based pH-UV-Vis spectroscopy was proposed for quantifying allura red in an energy drink product without the need for chromatographic analysis, and determining the colorant’s pKa without using any titration technique. In this study, UV-Vis spectroscopic data matrices were obtained from absorbance measurements at five different pH levels from pH 8 to pH 12 and arranged as a three-way array (wavelength x sample x pH). In the three-way analysis procedure, parallel factor analysis (PARAFAC) was implemented to decompose the three-way array into a set of trilinear components. Each set of three components relates to spectral, pH and relative concentration profiles …
Effective Microwave-Assisted Approach To 1,2,3-Triazolobenzodiazepinones
Via Tandem Ugi Reaction/Catalyst-Free
Intramolecular Azide–Alkyne Cycloaddition,
2021
State Scientific Institution “Institute for Single Crystals” of National Academy of Sciences of Ukraine, V. N. Karazin Kharkiv National University
Effective Microwave-Assisted Approach To 1,2,3-Triazolobenzodiazepinones Via Tandem Ugi Reaction/Catalyst-Free Intramolecular Azide–Alkyne Cycloaddition, Maryna O. Mazur, Oleksii S. Zhelavskyi, Eugene M. Zviagin, Svitlana V. Shishkina, Vladimir I. Musatov, Maksim A. Kolosov, Elena H. Shvets, Anna Yu. Andryushchenko, Valentyn A. Chebanov
Department of Chemistry: Faculty Publications
A novel catalyst-free synthetic approach to 1,2,3-triazolobenzodiazepinones has been developed and optimized. The Ugi reaction of 2-azidobenzaldehyde, various amines, isocyanides, and acids followed by microwave-assisted intramolecular azide–alkyne cycloaddition (IAAC) gave a series of target heterocyclic compounds in moderate to excellent yields. Surprisingly, the normally required ruthenium-based catalysts were found to not affect the IAAC, only making isolation of the target compounds harder while the microwave-assisted catalyst-free conditions were effective for both terminal and non-terminal alkynes
