Analytical Chemistry Commons^™

Photoelectrochemical Sensing Based On Zr-Mofs For Homocysteine Detection, Wen-Xia Dong, Guang-Ming Wen, Bin Liu, Zhong-Ping Li

Journal of Electrochemistry

Due to the independent form of the light source and detection system, photoelectrochemical (PEC) sensor has the advantages of low background, high sensitivity and simple operation. So far, PEC systems have been widely used in the fields including the actual detection of metal ions, biological antibodies or antigens in environmental pollutants. When the photosensitive material is irradiated by a light source with an energy being equal to or greater than its band gap, electrons (e^-) transition occurs from the valence band to the conduction band, leaving a hole (h⁺), at the same time, the generated electron-hole …

Structure Analysis Of Pemfc Cathode Catalyst Layer, Rui-Qing Wang, Sheng Sui

Journal of Electrochemistry

The sluggish oxygen reduction reaction (ORR) on the cathode of the proton exchange membrane fuel cell (PEMFC) has always been one of the key factors limiting its commercialization. The optimization of the cathode catalytic layer structure plays an important role in improving fuel cell performance and reducing production costs. In this paper, two different catalysts (platinum nanoparticles (Pt-NPs) and platinum nanowires (Pt-NWs)) were prepared by using catalyst coated substrate (CCS) method. By constructing a double-layer catalytic layer structure, we analyzed the effect of different catalytic layer structures by performing a single cell test. The results showed that the dense platinum …

Characterization Of Landfill Leachate For Enhanced Metal Recovery, Hanna Fulford, Amisha Shah, Inez Hua, Nadezhda Zyaykina, Lori Hoagland, Alejandro Rodriguez Sanchez, Umut Bicim

Discovery Undergraduate Interdisciplinary Research Internship

Landfills contain a trove of valuable materials, such as critical, precious, and rare earth metals, that are integral to the United State’s economy and national security. The leachate that filters through landfills picks up these materials, which allows for the possibility of recovery. For this research, samples will be analyzed from landfills throughout the Midwestern United States to provide a baseline on water quality constituents, elements present, and microbial activity. Preliminary data for this study was acquired by analyzing samples of landfill leachate from a landfill in northern Indiana. pH readings indicate that the leachate is slightly basic. It also …

Disease Biomarker Discovery And Fungal Metabolites Extraction Protocol Optimization Using Gcms Based Metabolomics, Chathuri Udeshika Gamlath Mohottige

Theses and Dissertations

Metabolomics is a powerful science that can be applied for the discovery of disease biomarkers, and investigation of altered metabolomes due to abiotic and biotic perturbations. This dissertation is focused on untargeted metabolomic applications to investigate fungal metabolite alterations associated with pathogenicity, fungal disease propagations, and symbiosis. This dissertation employs qualitative analysis of metabolite mixtures using HS-SPME coupled GC-MS and TMS derivatization followed by GC-MS analytical platforms. In the first study, we discovered a biomarker combination to diagnose fungal soft tissue disease in sweet potato at an early stage of disease propagation. We used an HS-SPME GC-MS untargeted metabolomics workflow …

Characterization Of Small Molecules And Ions By Atmospheric Pressure Ionization-Mass Spectrometry, Maleesha De Silva

Theses and Dissertations

Mass spectrometry (MS) has become a widely used technique for the characterization of a wide range of substances in diverse fields. The selection of appropriate ionization techniques, source parameters, charge carriers based on the analyte’s polarity is essential in MS as only the ions are detected. When using a soft ionization technique, single stage-MS at best provides only chemical composition; thus, tandem MS is needed to determine structural information and dissociation pathways. This dissertation focuses on the characterization of various small molecules and ions using different ionization techniques, charge carriers, and collision-induced dissociation (CID).

In Chapter II, commercially available ionic …

Bioactivity Assessment Of Veratrum Californicum Alkaloids, Madison Dirks

Boise State University Theses and Dissertations

The native Idaho plant Veratrum californicum is known to contain steroidal alkaloids that function as inhibitors of hedgehog signaling, a pathway utilized for the growth and differentiation of cells as well as proper tissue development. Veratrum californicum was originally noticed when pregnant ewes consumed the plant and later gave birth to lambs with craniofacial mutations such as a cyclopean eyes. These malformations were caused by the plant’s steroidal alkaloid cyclopamine blocking the hedgehog signaling pathway. This same pathway is used by more than 20 types of cancer for multiplication of cells. Additional alkaloids have been found in Veratrum californicum, …

Determining The Presence Of Biological Fluids In Peruvian Mummy Cloths Using The Liquid Chromatography Quadruple Time Of Flight Instrument, Tim Perksen, Joshua Sebree Ph.D.

Fall 2021 - Chemical Analysis Class Projects

A poster presenting the processes used and the results of analyzing the cloth from Peruvian mummies for the presence of biological fluids.

Identification Of Natural Dyes In Ancient Peruvian Mummy Cloths Using Lc/Ms/Ms, Shailah Mathews, Joshua Sebree Ph.D.

Fall 2021 - Chemical Analysis Class Projects

A poster presenting the processes used and the results of analyzing the natural dyes used on cloth from Peruvian mummies.

Detecting Oceanic Salt In Peruvian Mummy Cloths Using Scanning Electron Microscopy, Alexis Wirtz, Joshua Sebree Ph.D.

Fall 2021 - Chemical Analysis Class Projects

A poster presenting the processes and the results of analyzing cloth from Peruvian mummies for the presence of ocean salts.

Facile Nitrogen-Doping Of Screen-Printed Carbon Electrodes For Detection Of Hydrogen Peroxide, Emmanuel Nkyaagye

Electronic Theses and Dissertations

Screen-printed carbon electrodes (SPCEs) have garnered much attention as sensors due to their simplicity and relatively low cost. However, to impart necessary selectivity and sensitivity for specific applications, modification of the SPCE surface, which can involve time-consuming procedures or costly equipment/materials, is typically required. Here, a simple nitrogen-doping process based on NH₄OH was used to modify SPCEs prepared from commercially available ink for electrochemical detection of H₂O₂, a common target for biosensing strategies and indicator of cell stress. XPS studies showed that NH₄OH treatment of SPCEs led to a nearly 5-fold increase …

Effects Of Localized Oxygen Production By Electrolysis On The First-Generation Glucose Sensor Response, Nandita Halder

Graduate Theses and Dissertations

Glucose sensors are very important for detecting blood glucose both in vitro and in vivo. First-generation glucose biosensors were based on the glucose oxidase (GOx) enzyme using molecular oxygen as the electron acceptor and therefore oxygen dependent. Unfortunately for in-vivo work, oxygen in the body is variable and limited. Alternative approaches to overcome the oxygen dependency came with their own limitations. The widely used and commercially available ex-vivo glucose test strip uses a mediator in place of oxygen to free it from oxygen dependency. The mediator-based technology, in most cases cannot be transferred to in vivo applications due to the …

Rapid Method For Consistency And Concentration Reporting Of Cannabidiol Using 1H-Nmr And Computer-Assisted Chemical Software, Michael A. Fernando

University Honors Theses

An integrated computational method was demonstrated with hemp-derived Cannabidiol for an assessment of its purity and concentration. The sample was structurally verified, high purity, and 2.98 mmol/L in dissolved DMSO. The method presented is a general approach to assessing purity and concentration for any small organic molecule in CMC-Assist.

Amilorides Inhibit Sars-Cov-2 Replication In Vitro By Targeting Rna Structures, Martina Zafferani, Christina Haddad, Le Luo, Jesse Davila-Calderon, Liang-Yuan Chiu, Christian Shema Mugisha, Adeline G. Monaghan, Andrew A. Kennedy, Joseph D. Yesselman, Robert J. Gifford, Andrew W. Tai, Sebla B. Kutluay, Mei-Ling Li, Gary Brewer, Blanton S. Tolbert, Amanda E. Hargrove

Department of Chemistry: Faculty Publications

The SARS-CoV-2 pandemic, and the likelihood of future coronavirus pandemics, emphasized the urgent need for development of novel antivirals. Small-molecule chemical probes offer both to reveal aspects of virus replication and to serve as leads for antiviral therapeutic development. Here, we report on the identification of amiloride-based small molecules that potently inhibit OC43 and SARS-CoV-2 replication through targeting of conserved structured elements within the viral 5′-end. Nuclear magnetic resonance–based structural studies revealed specific amiloride interactions with stem loops containing bulge like structures and were predicted to be strongly bound by the lead amilorides in retrospective docking studies. Amilorides represent the …

Nuscon: A Community-Driven Platform For Quantitative Evaluation Of Nonuniform Sampling In Nmr, Yulia Pustovalova, Frank Delaglio, D. Levi Craft, Haribabu Arthanari, Ad Bax, Martin Billeter, Mark J. Bostock, Hesam Dashti, D. Flemming Hansen, Sven G. Hyberts, Bruce A. Johnson, Krzysztof Kazimierczuk, Hengfa Lu, Mark Maciejewski, Tomas M. Miljenović, Mehdi Mobli, Daniel Nietlispach, Vladislav Orekhov, Robert Powers, Xiaobo Qu, Scott Anthony Robson, David Rovnyak, Gerhard Wagner, Jinfa Ying, Matthew Zambrello, Jeffrey C. Hoch, David L. Donoho, Adam D. Schuyler

Department of Chemistry: Faculty Publications

Although the concepts of nonuniform sampling (NUS) and non-Fourier spectral reconstruction in multidimensional NMR began to emerge 4 decades ago (Bodenhausen and Ernst, 1981; Barna and Laue, 1987), it is only relatively recently that NUS has become more commonplace. Advantages of NUS include the ability to tailor experiments to reduce data collection time and to improve spectral quality, whether through detection of closely spaced peaks (i.e., “resolution”) or peaks of weak intensity (i.e., “sensitivity”). Wider adoption of these methods is the result of improvements in computational performance, a growing abundance and flexibility of software, support from NMR spectrometer vendors, and …

Corrosion Prevention On Aluminum Alloy, Andrea Brenner

Symposium of Student Scholars

Aluminum alloy (Al-alloy) is a widely used metal in construction, aerospace, aviation, and other necessary fields due to its lightweight and tweakable properties. However, corrosion is inevitable on metals and alloys, and that causes millions of dollars of revenue loss every year. Therefore, we propose to research fabricating coating to prevent corrosion on Al-alloy. This study uses an iron-based metal-organic framework (MOF) and polyurethane (PU) based composite coating to prevent corrosion on the Al-alloy. The makeup of the composite material is changed by varying the percentage of MOF. In addition, a binder is also used to enhance the homogenization between …

Impact Of The Water Content In The Therapeutic Deep Eutectic Solvents, Noam Lewit, James Stewart, Oluseyi Olawuyi, Mohammed A. Halim

Symposium of Student Scholars

Deep eutectic solvent(s) (DES) are the new generation of greener and more sustainable solvents, formulated by the complex of hydrogen bond in the molecules. The solvents allow us to achieve a significantly lower freezing point compared to its components, an affordable formulation and a technology that is typically formulated to improve the bioavailability of a drug. In this research project, we synthesized an ibuprofen-menthol based therapeutic deep eutectic solvent and investigated how water content affects the structure and dynamics of the solvent. For synthesizing the ibuprofen-menthol DES, 2.0629 g of Ibuprofen and 4.6881 g of menthol were placed in a …

Analysis Of Kavalactones In Various Consumptive Kava Samples Using Gc-Ms, Stephanie O'Kon

Symposium of Student Scholars

Piper Methysticum, or Kava, is a plant native to the Pacific Islands and is used in various ceremonial and cultural aspects. In the United States, Kava has many dietary forms from sleep aids to mood boosters. The active ingredients found in Kava roots, kavalactones, give users psychoactive effects. However, there are concerns regarding toxicity and unknown safety consumption limits. There are six major kavalactones, and possibly more that have been reported, but not fully researched. The one of interest in this study is kavain. Different solvents, diethyl ether and acetone, have been used in extracting kavalactones from cut kava root. …

3-Dimensional Structural Determination Of Epidermal Growth Factor-Like Repeat 27 From Mouse Notch1 Using Nuclear Magnetic Resonance Spectroscopy, Justin Grennell

LSU Doctoral Dissertations

NOTCH1 has been associated with a variety of human ailments, such as cancer and heart disease. NOTCH1 is a transmembrane protein that contains 36 epidermal growth factor-like (EGF) repeats, which facilitate cell signaling by binding proteins on neighboring cells. Each repeat contains about 40 amino acids and has to be folded in a specific manner to function properly. The amino acid sequence, carbohydrate pattern, and calcium-binding sites of EGF-like repeats vary, but the pattern along the 36-repeat chain is conserved. The Abruptex region (EGF24-29) of NOTCH1 is a highly glycosylated (having undergone sugar addition) and flexible region, which gained its …

Investigating Thermodynamics And Kinetics Of Methylene Blue And Eriochrome Black-T Adsorption On Activated Carbon Prepared From Coconut Husk, Abdul Rahman Wahoud, Lotfi Abdul Samed Bawazer

Hadhramout University Journal of Natural & Applied Sciences

In this research, the adsorption process was studied for methylene blue eriochrome black-T from aqueous solutions on the surface of activated carbon prepared from coconut husk by chemical activation with potassium hydroxide. The results show that the adsorption isotherm for methylene blue follows the Langmuir model while it follows the Freundlich model and the maximum adsorption capacity was 909 mg/g for methylene blue and 262 mg/g for eriochrome black-T. The equilibrium contact time reached in about 90 minutes at lower concentrations and 120 minutes at higher concentrations. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equations were selected to follow …

Kinetic, Equilibrium And Application Studies For Removal Of Methylene Blue From Aqueous Solution Using Sesbenia Dates Activated Carbon, Mohammed Saleh Bashanaini, Gameel Ahmed Baghaffar, Waheeb Abdellah Bin Frejan

Hadhramout University Journal of Natural & Applied Sciences

In the present work, sesbenia dates as local agricultural waste has been successfully used for the preparation of activated carbon (AC) by sulphuric acid. This sulphuric acid based activated carbon (SD) and (MSACS) were used for the removal of one cationic dye viz., methylene blue (MB) from aqueous solutions. The structure and physical and chemical properties of (SD) and (MSACS) are investigated using (FTIR) and (SEM) analysis and pH surface and Boehm titration. The effect of the differential experimental parameters controlling the adsorption of dye onto (SD) and (MSACS), were thoroughly investigated, such as the effect of pH, initial dye …