Analytical Chemistry Commons^™

Application Of Adamantane Schiff Base Nickel Complexes/Graphene Oxide/Glassy Carbon Modified Electrode In Detection Of Carmine, Peng Guo, Zheng Liu, Hai-Ying Li, Li-Ming Ma

Journal of Electrochemistry

The Schiff base nickel complexes/graphene oxide/glassy carbon electrodes were prepared by embedded method and electrodeposition on which were used to quantitatively detect the contents of carmine. Cyclic voltammetry, chronoamperometry, scanning electron microscopy (SEM) and other methods were employed to characterize properties and morphologies of the modified electrodes. The results show that the adamantane double Schiff base nickel complexes/graphene oxide/glassy carbon electrode had high electric catalytic activity toward carmine oxidation reaction, and might provide an easy and quick way to detect carmine content with good reproducibility.

Engineering Fret Biosensors For Microrna Presence/Absence Analysis, Nicholas E. Larkey, Sean M. Burrows

Biomedical Engineering Western Regional Conference

No abstract provided.

Iterative Non-Proteinogenic Residue Incorporation Yields Α/Β-Peptides With A Helix-Loop-Helix Tertiary Structure And High Affinity For Vegf, James W. Checco, Samuel H. Gellman

Department of Chemistry: Faculty Publications

Inhibition of specific protein-protein interactions is attractive for a range of therapeutic applications, but the large and irregularly shaped contact surfaces involved in many such interactions make it challenging to design synthetic antagonists. Here, we describe the development of backbone-modified peptides containing both α- and β-amino acid residues (“α/β-peptides”) that target the receptor-binding surface of vascular endothelial growth factor (VEGF). Our approach is based on the Z-domain, which adopts a three-helix bundle tertiary structure. We show how a two-helix “mini-Z-domain” can be modified to contain β and other non-proteinogenic residues while retaining the target-binding epitope using iterative non-natural residue incorporation. …

A Dilute-And-Shoot Flow-Injection Tandem Mass Spectrometry Method For Quantification Of Phenobarbital In Urine, Ravali Alagandula, Xiang Zhou, Baochuan Guo

Chemistry Faculty Publications

RATIONALE: Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is the gold standard of urine drug testing. However, current LC-based methods are time consuming, limiting the throughput of MS-based testing and increasing the cost. This is particularly problematic for quantification of drugs such as phenobarbital, which is often analyzed in a separate run because they must be negatively ionized.

METHODS: This study examined the feasibility of using a dilute-and-shoot flow-injection method without LC separation to quantify drugs with phenobarbital as a model system. Briefly, a urine sample containing phenobarbital was first diluted by 10 times, followed by flow injection of the diluted sample …

Assessment Of Four Solvents For Extraction And Analysis Of The Chemical Composition Of Sansevieria Extrafoliar Nectar Drops By Gas Chromatography-Mass Spectrometry, Hope L. Juntunen, Patrick Videau, Donna Hazelwood, Michael Gaylor

Research & Publications

In the latter part of the 20th century, much effort was devoted to elucidating the chemical constituents of floral and extrafloral nectar secretions, with the primary aim of understanding their ecological roles, especially in regards to attracting pollinators. But, nearly all these studies focused on determining sugar and amino acid constituents. Only a few studies have reported more comprehensive assessments of the organic chemical constituents of plants, with none of those reporting such efforts for Sansevieria taxa (common houseplants known to purify air by bioaccumulating pollutants). To address this knowledge gap, we evaluated the efficacy of four organic solvents with …

Reply To ‘On The Bonding In Ligand-Protected Gold Clusters’, Wen Wu Xu, Xiao Cheng Zeng, Yi Gao

Xiao Cheng Zeng Publications

In the recent Correspondence, Professor Henrik Grönbeck made several comments on the recently developed grand unified model (GUM), in particular using the ligand-protected gold cluster [Au₂₅(SR)₁₈]¹⁻ as an example. We noted that the latter cluster can be viewed as belonging to a special group of ligand-protected gold clusters that contain one or several icosahedral Au₁₃ motifs. For this group of clusters, a secondary block Au₁₃(8e) has been identified as a more convenient way to describe their structure anatomy and evolution. Another extension of the GUM is the identification of the new elementary …

Phthalate And Non-Phthalate Plasticizers In Indoor Dust From Childcare Facilities, Salons, And Homes Across The Usa, Bikram Subedi, Kenneth D. Sullivan, Birendra Dhungana

Faculty & Staff Research and Creative Activity

The quality of indoor environment has received considerable attention owing to the declining outdoor human activities and the associated public health issues. The prolonged exposure of children in childcare facilities or the occupational exposure of adults to indoor environmental triggers can be a culprit of the pathophysiology of several commonly observed idiopathic syndromes. In this study, concentrations of potentially toxic plasticizers (phthalates as well as non-phthalates) were investigated in 28 dust samples collected from three different indoor environments across the USA. The mean concentrations of non-phthalate plasticizers [acetyl tri-n-butyl citrate (ATBC), di-(2-ethylhexyl) adipate (DEHA), and diisobutyl adipate (DIBA)] were found …

Mass Loading And Removal Of Pharmaceuticals And Personal Care Products Including Psychoactives, Antihypertensives, And Antibiotics In Two Sewage Treatment Plants In Southern India, Bikram Subedi, Keshava Balakrishna, Derrick Ian Joshua, Kurunthachalam Kannan

Faculty & Staff Research and Creative Activity

Environmental contamination by pharmaceuticals and personal care products (PPCPs) is barely studied in India despite being one of the largest global producers and consumers of pharmaceuticals. In this study, 29 pharmaceuticals and six metabolites were determined in sewage treatment plants (STPs) in Udupi (STP_U: population served ~150,000) and Mangalore (STP_M: population served ~450,000); the measured mean concentrations ranged from 12 to 61,000 ng/L and 5.0 to 31,000 ng/L, respectively. Atorvastatin (the most prescribed antihypercholesterolemic in India), mefenamic acid, and paraxanthine were found for the first time in wastewater in India at the mean concentrations of 395 …

Fluorogenic Protein Labeling Using A Genetically Encoded Unstrained Alkene, Xin Shang, X. Song, C. Faller, R. Lai, H. Li, R. Cerny, Wei Niu, Jiantao Guo

Department of Chemistry: Faculty Publications

We developed a new fluorogenic bioorthogonal reaction that is based on the inverse electron-demand Diels–Alder reaction between styrene (an unstrained alkene) and a simple tetrazine. The reaction forms a new fluorophore with no literature precedent. We have identified an aminoacyl-tRNA synthetase/tRNA pair for the efficient and site-specific incorporation of a styrene-containing amino acid into proteins in response to amber nonsense codon. Fluorogenic labeling of purified proteins and intact proteins in live cells were demonstrated. The fluorogenicity of the styrene–tetrazine reaction can be potentially applied to the study of protein folding and function under physiological conditions with low background fluorescence interference.

Soft Robotic Actuators, Filip Ilievski, Xin Chen, Aaron D. Mazzeo, George M. Whitesides, Robert F. Shepherd, Ramses V. Martinez, Won Jae Choi, Sen Wai Kwok, Stephen A. Morin, Adam Stokes, Zhihong Nie

Department of Chemistry: Faculty Publications

A soft robotic device includes a flexible body having a width, a length and a thickness, wherein the thickness is at least 1 mm, the flexible body having at least one channel disposed within the flexible body, the channel defined by upper, lower and side walls, wherein at least one wall is strain limiting; and a pressurizing inlet in fluid communication with the at least one channel, the at least one channel positioned and arranged such that the wall opposite the strain limiting wall preferentially expands when the soft robotic device is pressurized through the inlet.

The Development Of Chemical Methods To Discover Kinase Substrates And Map Cell Signaling With Gamma-Modified Atp Analog-Dependent Kinase-Catalyzed Phosphorylation, Dissanayaka Mudiyanselage Maheeka Madhubashini Embogama

Wayne State University Dissertations

Kinase-catalyzed phosphorylation plays an important role in cell physiology by regulating a myriad of cellular functions. Thus aberrant kinase activity is implicated in various diseases. Methods are needed to discover kinase substrates and map signaling pathways to explore biology and to help drug discovery. A few techniques are currently available to discover kinase substrate and map cell signaling. However, to augment kinase substrate discovery approaches, it is essential to develop alternative techniques. Pflum has recently discovered cosubstrate promiscuity of protein kinases with gamma-modified ATP analogs. Here, kinase-catalyzed biotinylation with ATP-biotin was used to develop novel tools to discover kinase substrates …

Gas-Phase Ion Spectroscopy Of Nucleobases And Mononucleotides: Models For Higher Order Nucleic Acids, Yuan-Wei Nei

Wayne State University Dissertations

Experiments examining the structures and stabilities of protonated and sodium cationized nucleobases, and deprotonated DNA and RNA mononucleotides are presented and discussed in this dissertation. These studies were carried out using the infrared multiple photon dissociation (IRMPD) action spectroscopy technique that utilizes a Fourier transform ion cyclotron mass spectrometer (FT-ICR MS) coupled to a free electron laser (FEL) located at the Radboud University Nijmegen. Ionic species of these biologically important complexes were generated using an electrospray ionization source and then mass isolated to have their infrared (IR) spectra measured by the experimental apparatus. Detailed analysis of the IR spectra measured …

Fidelity Of Implementation: An Overlooked Yet Critical Construct To Establish Effectiveness Of Evidence-Based Instructional Practices, Marilyne Stains, Trisha Vickrey

Department of Chemistry: Faculty Publications

The discipline-based education research (DBER) community has been invested in the research and development of evidence-based instructional practices (EBIPs) for decades. Unfortunately, investigations of the impact of EBIPs on student outcomes typically do not characterize instructors’ adherence to an EBIP, often assuming that implementation was as intended by developers. The validity of such findings is compromised, since positive or negative outcomes can be incorrectly attributed to an EBIP when other factors impacting implementation are often present. This methodological flaw can be overcome by developing measures to determine the fidelity of implementation (FOI) of an intervention, a construct extensively studied in …

Fluorogenic Protein Labeling Using A Genetically Encoded Unstrained Alkene, X. Shang, X. Song, C. Faller, R. Lai, H. Li, Ronald Cerny, Wei Niu, Jiantao Guo

Department of Chemistry: Faculty Publications

We developed a new fluorogenic bioorthogonal reaction that is based on the inverse electron-demand Diels–Alder reaction between styrene (an unstrained alkene) and a simple tetrazine. The reaction forms a new fluorophore with no literature precedent. We have identified an aminoacyl-tRNA synthetase/tRNA pair for the efficient and site-specific incorporation of a styrene-containing amino acid into proteins in response to amber nonsense codon. Fluorogenic labeling of purified proteins and intact proteins in live cells were demonstrated. The fluorogenicity of the styrene–tetrazine reaction can be potentially applied to the study of protein folding and function under physiological conditions with low background fluorescence interference.

Assessment Of Surface Water Contamination From Coalbed Methane Fracturing-Derived Volatile Contaminants In Sullivan County, Indiana, Usa, Nicholas Meszaros, Bikram Subedi, Tristan Stamets, Naima Shifa

Faculty & Staff Research and Creative Activity

There is a growing concern over the contamination of surface water and the associated environmental and public health consequences from the recent proliferation in hydraulic fracturing in the USA. Petroleum hydrocarbon-derived contaminants of concern [benzene, toluene, ethylbenzene, and xylene (BTEX)] and various dissolved cations and anions were spatially determined in surface waters around 14 coalbed methane fracking wells in Sullivan County, IN, USA. At least one BTEX was detected in 69% of sampling sites (n=13) and 23% of sampling sites were found to be contaminated with all of the BTEX. Toluene was the most common BTEX compound detected across all …

Probing The Structural Evolution Of Gold−Aluminum Bimetallic Clusters (Au2AlN−, N = 3−11) Using Photoelectron Spectroscopy And Theoretical Calculations, Navneet S. Khetrapal, Tian Jian, Gary V. Lopez, Seema Pande, Lai-Sheng Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We report a combined photoelectron spectroscopy and theoretical study of the structural evolution of aluminum cluster anions doped with two gold atoms, Au₂Al_n^– (n = 3−11). Well-resolved photoelectron spectra have been obtained at several photon energies and are used to compare with theoretical calculations to elucidate the structures of the bimetallic clusters. Global minima of the Au₂Al_n^– clusters were searched using the basin-hopping method combined with density functional theory calculations. Vertical detachment energies were computed for the low-lying isomers with the inclusion of spin−orbit effects and were used to generate simulated …

Latent Fingerprint Enhancement On A Brass Metal Surface Using Paint Electrodeposition, Reika D. Haskell

Online Theses and Dissertations

Fingerprint evidence recovered at a crime scene plays a key role in apprehending a suspect. Cyanoacrylate fuming is one the most successful methods of enhancing fingerprints from metallic surfaces. Despite the success of cyanoacrylate fuming, fingerprint recovery on fired cartridge casings is rarely successful. Therefore, a new fingerprint development method is needed to enhance fingerprint evidence that may still be present on fired cartridge casings. The aim of this research project is to study the use of metal and paint electrodeposition to enhance fingerprints on a brass metal surface.

High throw power paint was used in the initial study; high …

Synthesis And Analysis Of Folate Histidine, Alexander Kampner

All Capstone Projects

A compound was specifically designed to further aid research on the detection and treatment of folate receptor positive cancer cells. A small but complex peptide chain was commercially produced to have a flexible glycine spacer and a six-histidine tag. Histidine tagging was chosen for its ability to bind to nickel. The compound in this report was purified and analyzed by HPLC and confirmed via mass spectrometry. This binding capacity and the ability of folate conjugates to bind to cancer cell receptors have both been explored for the past quarter of a century [1-3]. Folate conjugates have been successfully used as …

A Quartz Crystal Microbalance Study Of Thiol:Ene Poly(Ionic Liquid) Polymerization And Gas Absorption, Yueming Wu

Murray State Theses and Dissertations

ABSTRACT

The polymerization process of, and gas absorption by, imidazolium-containing thiol:ene poly (ionic liquid)s (PILs), prepared from bisallylimidazolium bis(trifluoromethyl sulfonyl)imide [NTf₂^-] and pentaerythritoltetrakis(3 mercaptopropionate), was studied. The thiol:ene PILs examined were recently reported by groups at Murray State University. The advantage of thiol:ene PILs over other reported PILs is that thiol:ene polymers are made rapidly by UV exposure and exhibit high mechanical and thermal stability due to high cross-linking. The properties of interest for the thiol:ene PILs were studied using a quartz crystal microbalance (QCM). QCM techniques are based on the piezoelectric effect, where certain crystals (e.g., …

Investigating The Atmospheric Production Of Perchlorate: Inference From Polar Ice Cores, Thomas S. Cox

Electronic Theses and Dissertations

Perchlorate (ClO₄) in the environment is of concern, because of potential health risks to humans, among other reasons. Evidence suggests that the majority of environmental perchlorate is formed in the atmosphere (likely in the stratosphere), in chemical processes involving ozone and stratospheric chlorine. A lack of knowledge in regards to the processes has resulted in a limited understanding of the environmental conditions and variables that influence perchlorate production and consequently perchlorate prevalence and variability in the environment. In this study, perchlorate was measured, using an established ion chromatography-­‐electrospray ionization-­‐tandem mass spectrometry (IC-­‐ESI-­‐ MS/MS) technique, in over 1,600 snowpit …

Comprehensive Structural, Thermal And Toxicological Characterization Of 1-Ethyl-3-Methylimidazolium Alkylbenzenesulfonate Ionic Liquids, Hiranmayee Kandala

Electronic Theses and Dissertations

Synthesis and characterization of 1-ethyl-3- methylimidazolium alkylbenzenesulfonate ionic liquids for extraction of lignin from prairie cord grass have been studied. The ionic liquids (ILs) 1-ethyl-3- methylimidazolium benzenesulfonate (EBS), 1-ethyl-3- methylimidazolium toluenesulfonate (ETS) and 1-ethyl-3- methylimidazolium xylenesulfonate (EXS) have been synthesized in this research. An extensive structural, physical, thermal and toxicological characterization has been performed to understand the behavior of these ionic liquids. The reaction yield for the synthesis of EBS, ETS, and EXS ionic liquids was determined to be 91.2 ± 1.5 %, 96.1 ± 0.7 %, 99.0 ± 0.5 % respectively. Spectral analysis using NMR and FTIR confirms the …

A Novel Method For Determination Of Ammonium Isotope Ratios With Electrospray Ionization Mass Spectrometry, Rebecca J. Chmiel

Honors Theses

Nitrogen (¹⁵N) isotope tracer studies are an invaluable tool for understanding the rate of N transformations in the environment. A mechanistic understanding of N cycling is critical to management of excess N availability in freshwater and marine ecosystems. Conventional methods for measuring ¹⁵N:¹⁴N of dissolved inorganic nitrogen species are time consuming and require large sample volumes. Here, we present a technique for measuring ¹⁵N:¹⁴N in ammonium (NH₄⁺) using electrospray ionization mass spectrometry (ESI-MS). NH₄⁺ present in small volumes of sample (3 ml) is complexed with phenol via …

Choline Chloride Eutectics: Low Temperature Applications, Kaila M. Kuehn, Camille M. Massmann, Natalie R. Sovell

The Journal of Undergraduate Research

Deep eutectic solvents (DESs) have a lower melting point than each of their individual components due to ion dipole interactions or hydrogen bonding. Traditionally, DES are used for processing metals through plating and have many synthesis applications. DES are able to be substituted for hazardous solvents that are traditionally used for metal plating and synthesis. This, along with many other advantageous properties, appear promising for the use of DESs as solvents or for use in electrochemical systems, particularly at low temperatures. Choline chloride:propylene glycol was a novel DES synthesized and analyzed for its properties, including melting point, viscosity, conductivity, heat …

The Analysis Of Flavor Compounds In Green Tea Using Ice Concentration Linked With Extractive Stirrer (Icecles), Abdullah H. Alluhayb

Electronic Theses and Dissertations

Sample preparation of target components from food samples is one of the most difficult steps in this type of analysis. Many extraction techniques have been used for this purpose, such as liquid-liquid extraction (LLE), accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), solid-phase extraction (SPE), solid-phase microextraction (SPME), and stir bar sorptive extraction (SBSE). Although each of these techniques works well, they each have a number of disadvantages, including selectivity, relatively high cost, long preparation time, and matrix effects. Ice concentration linked with extractive stirrer (ICECLES) is a promising new sample preparation technique, especially for the extraction of relatively polar compounds, …

Further Development Of Raman Spectroscopy For Body Fluid Investigation : Forensic Identification, Limit Of Detection, And Donor Characterization, Claire K. Muro

Legacy Theses & Dissertations (2009 - 2024)

The challenges to forensic body fluid analysis have placed limitations on the type of information that investigators can acquire and how that information can be collected. In recent years, Raman spectroscopy has proven itself useful for characterizing body fluids. In 2008, a large-scale investigation was undertaken to explore the use of Raman spectroscopy as a means of identifying body fluids. This work resulted in multidimensional Raman spectroscopic signatures for the five main body fluids: semen, peripheral blood, saliva, vaginal fluid, and sweat. These studies were incredibly successful and created the foundation for years of continued research. Accordingly, the studies included …

Structure And Characterization Of A Class 3b Proline Utilization A: Ligand-Induced Dimerization And Importance Of The C-Terminal Domain For Catalysis, David A. Korasick, Thameesha T. Gamage, Shelbi Christgen, Kyle M. Stiers, Lesa J. Beamer, Michael T. Henzl, Donald F. Becker, John J. Tanner

Department of Chemistry: Faculty Publications

The bifunctional flavoenzyme proline utilization A (PutA) catalyzes the two-step oxidation of proline to glutamate using separate proline dehydrogenase (PRODH) and L-glutamate-y-semialdehyde dehydrogenase active sites. Because PutAs catalyze sequential reactions, they are good systems for studying how metabolic enzymes communicate via substrate channeling. Although mechanistically similar, PutAs vary widely in domain architecture, oligomeric state, and quaternary structure, and these variations represent different structural solutions to the problem of sequestering a reactive metabolite. Here, we studied PutA from Corynebacterium freiburgense (CfPutA), which belongs to the uncharacterized 3B class of PutAs.A2.7A˚ resolution crystal structure showed the canonical arrangement of PRODH, L-glutamate-y-semialdehyde dehydrogenase, …

Purification And Analysis Of A Pteroic Acid Conjugate, Naveen Kumar Ganji

All Capstone Projects

(FR) is overexpressed on the cell membrane in cancer tissues and activated macrophages associated with rheumatoid conditions. However, FR is restricted in normal healthy tissues. Folic acid has shown high affinity to folate receptors and thus can be used in targeting the tumor cells. Folic acid residue, pteroic acid is also used in several studies that are involved in targeting cancer cells. Several examples include technetium -99m radiotracer labelled pteroyl-lys conjugates, pteroic acid-conjugated nitroheterocyclic phosphoramidates..

In this project, we were successfully able to conjugate pteroic acid with polyethylene Glycol-Amine to create an elegant building block(pte-PEG-amine) for synthesis of future imaging …

Impact Of Timber Harvest On Mercury Mobilization In A Mixed Pine And Hardwood Forest And Adjacent Lake In Mississippi, Mary Kristen Dickerson

Electronic Theses and Dissertations

With 65% of land area covered in forest, Mississippi is a leader in the timber industry. Whereas forestry provides numerous benefits for humans and wildlife, forest harvest has been hypothesized to increase mercury (Hg) mobilization to aquatic systems. In a forest, Hg mostly accumulates in the upper layer of soil, where associates with organic matter. This top soil is exposed after clear-cutting and thus more susceptible to runoff. Harvest may also change the net balance between Hg methylation and demethylation by microorganisms through changes in redox conditions and addition of carbon sources from decaying logging residues. To better understand the …

Quantitative Analysis Of Tobacco-Specific Nitrosamines And Their Precursor Alkaloids In Tobacco Extracts, Celeste T. Wilkinson

Theses and Dissertations

Tobacco-specific nitrosamines (TSNA) are carcinogenic constituents derived from alkaloids in tobacco. Researchers are actively exploring several avenues to reduce TSNA levels in tobacco products like moist snuff tobacco. The focus of the research presented within is the quantitative analysis of TSNA in tobacco, specifically N’-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1(3-pyridyl)-1-butanone (NNK), N’-nitrosoanatabine (NAT), and N’-nitrosoanabasine (NAB).

Tobacco alkaloids and nitrosamines in tobacco are currently analyzed by different instrumentation due to orders of magnitude difference in their concentrations, chromatographic separation challenges due to structural similarities, and similar mass fragmentation patterns. An analytical column using silica and 1,2-bis(siloxy)ethane hybrid particles of 1.7 µm size is …

Nitric Oxide Release From Poly(Lactic-Co-Glycolic Acid) Nanoparticles And Titanium Alloy, Nina A. Reger

Electronic Theses and Dissertations

Current methods for the treatment of bacterial infection involve the use of systemic antibiotics, which are high concentrations of antibiotics delivered over a long period time. Unfortunately, the use of systemic antibiotics can cause harmful side effects to the patient and increases the possibility for antibiotic resistance. The delivery of antibiotics or alternative antimicrobial compounds, such as nitric oxide, directly to the site of infection would decrease the amount of antibiotic necessary to treat a bacterial infection.

Poly (lactic-co-glycolic acid)/polyvinyl alcohol nanoparticles and a titanium- aluminum-vanadium metal oxide alloy implant were surface functionalized to deliver nitric oxide. Polymer nanoparticles can …