Chemistry Commons^™

Microscopic And Spectroscopic Analysis Of Wo3 And Ti-Doped Wo3 Thin Films, Young Taek Yun

Open Access Theses & Dissertations

Tungsten oxide (WO3) has been a subject of high interest for its unique properties, and recently for its importance in different types of industrial applications which ranges from non-emissive displays, optical, microelectronic, catalytic/photocatalytic, humidity, temperature, gas, and biosensor devices. In this study, WO3 and Ti doped thin films were prepared using radio frequency magnetron reactive sputtering at different substrate temperatures ranging from room temperature to 500 ºC in increments of 100 ºC. After forming a hypothesis based on knowledge of established WO3 properties, we attempt in this work to investigate how the doping influences the roughness and the mean grain …

Quantitative Analysis Of Some Important Metals And Metalloids In Tobacco Products By Inductively Coupled Plasma-Mass Spectrometry (Icp-Ms), Syed Ghulam Musharraf, Muhammad Shoaib, Amna Jabbar Siddiqui, Muhammad Najam-Ul-Haq, Aftab Ahmed

Pharmacy Faculty Articles and Research

Background: Large scale usage of tobacco causes a lot of health troubles in human. Various formulations of tobacco are extensively used by the people particularly in developing world. Besides several toxic tobacco constituents some metals and metalloids are also believed to pose health risks. This paper describes inductively coupled plasma-mass spectrometric (ICP-MS) quantification of some important metals and metalloids in various brands of smoked, sniffed, dipped and chewed tobacco products.

Results: A microwave-assisted digestion method was used for sample preparation. The method was validated by analyzing a certified reference material. Percentage relative standard deviation (% R.S.D.) between recovered …

Dynamic Light Scattering And Microelectrophoresis: Main Prospects And Limitations, Vuk Uskoković

Pharmacy Faculty Articles and Research

Microelectrophoresis based on the dynamic light scattering (DLS) effect has been a major tool for assessing and controlling the conditions for stability of colloidal systems. However, both the DLS methods for characterization of the hydrodynamic size of dispersed submicron particles and the theory behind the electrokinetic phenomena are associated with fundamental and practical approximations that limit their sensitivity and information output. Some of these fundamental limitations, including the spherical approximation of DLS measurements and an inability of microelectrophoretic analyses of colloidal systems to detect discrete charges and differ between differently charged particle surfaces due to rotational diffusion and particle orientation …

Development Of Mass Spectrometric Methods For The Analysis Of Serotonin And Related Compounds In Biological Matrices, Merisa Moriarty

Theses

Serotonin is a major neurotransmitter in the brain and affects various functions both in the brain and in the rest of the body. It has been linked to depression, migraines, and aggression, as well as many psychiatric disorders including schizophrenia, dementia and anorexia nervosa. It also has been associated with conditions like Alzheimer’s disease along with other neurotransmitters such as dopamine.

The aim of this research project is to develop various mass spectrometric methods for the analysis of serotonin, dopamine and similar indoles in both urine and serum matrices. This thesis provides extensive reviews detailing a general overview of serotonin …

Investigation Of Factors Influencing Trichloromethane Levels In Milk And Its Control., Siobhan Ryan

Theses

Trichloromethane (TCM) is an undesirable chemical residue that can develop in milk. While TCM levels in milk are not within ranges of public health concern, it is important that minimal levels are maintained in order to promote the marketing of Irish dairy products abroad. Germany has enacted strict regulations on TCM concentrations in foodstuffs with a recommended level of0.002 mg/kg and re-analyse those milks, subsequent to cause identification and provision of advice on reducing TCM levels in milk. Milk samples were analysed using Gas chromatography (GC) with electron capture detection. The GC method was adapted and a standard curve was …

Techniques For Sensor-Integrated Robotic Systems: Raman Spectra Analysis, Image Guidance, And Kinematic Calibration, Luke Anthony Reisner

Wayne State University Dissertations

Robotics and sensor technology have made impressive advancements over the years. There are now robotic systems that help perform surgeries or explore the surface of Mars, and there are sensors that detect trace amounts of explosives or identify diseased human tissue. The most powerful systems integrate robots and sensors, which are natural complements to each other. Sensors can provide information that might otherwise be unavailable due to indirect robotic manipulation (e.g., images of the target environment), and robots can provide suitably precise positioning of an analytical sensor.

To have an effective sensor-integrated robotic system, multiple capabilities are needed in the …

Electrochemistry, Transport Properties And Electronic Spectroscopy Of Lanthanide Solutes In Bis(Trifluoromethylsulfonyl)Imide-Based Ionic Liquids, Yunfeng Pan

Electronic Theses and Dissertations

No abstract provided.

Features For Non-Targeted Cross-Sample Analysis With Comprehensive Two-Dimensional Chromatography, Stephen E. Reichenbach, Xue Tian, Chiara Cordero, Qingping Tao

School of Computing: Faculty Publications

This review surveys different approaches for generating features from comprehensive two-dimensional chromatography for non-targeted cross-sample analysis. The goal of non-targeted cross-sample analysis is to discover relevant chemical characteristics (such as compositional similarities or differences) from multiple samples. In non-targeted analysis, the relevant characteristics are unknown, so individual features for all chemical constituents should be analyzed, not just those for targeted or selected analytes. Cross-sample analysis requires matching the corresponding features that characterize each constituent across multiple samples so that relevant characteristics or patterns can be recognized. Non-targeted, cross-sample analysis requires generating and matching all features across all samples. Applications of …

Biosensing Systems For The Detection Of Bacterial Quorum Sensing Molecules: A Tool For Investigating Bacteria-Related Disorders And Food Spoilage Prevention, Nilesh G. Raut

Theses and Dissertations--Chemistry

Quorum sensing enables bacteria to communicate with bacteria of the same or different species, and to modulate their behavior in a cell-density dependent manner. Communication occurs by means of small quorum sensing signaling molecules (QSMs) whose concentration is proportional to the population size. When a QSM threshold concentration is reached, certain genes are expressed, thus allowing control of several processes, such as, virulence factor production, antibiotic production, and biofilm formation. Not only many pathogenic bacteria are known to produce QSMs, but also QSMs have been identified in some bacteria-related disorders. Therefore, quantitative detection of QSMs present in clinical samples may …

The Application Of Raman Spectroscopy As A Confirmatory Blood Test In The Presence Of Sodium Hypochlorite Cleaners In In Comparison With Presumptive Blood Tests, Aliea Anoshaa Afnan

Legacy Theses & Dissertations (2009 - 2024)

Popular presumptive tests for blood include: Luminol, tetramethylbenzidine (TMB), leucomalachite green (LMG), phenolphthalein, and Hemastix® [3]. These presumptive tests have been reviewed with respect to their sensitivity, specificity, and DNA degradation. In this study, the aforementioned presumptive tests were subjected to bloodstains deposited on cotton contaminated with all-purpose bleach and compared with Raman spectroscopy as an application of a confirmatory blood test. Samples were tested for interference with the all-purpose bleach to determine the selectivity of the presumptive tests. Tetramethylbenzidine, leucomalachite green, and phenolphthalein all yielded inconclusive results when applied to a contaminated sample. Luminol and Hemastix® yielded a positive …

Fractional Comparison Of Arson Accelerants Using Advanced Distillation, Sarah Clickner

Legacy Theses & Dissertations (2009 - 2024)

Detection of accelerants is often critical in proving a fire was intentional. Establishing a fire was intentionally set is not an easy task and hinges on the preservation of accelerant present in fire debris. Various accelerants have previously been studied using the advanced distillation method to get fractional composition information. The resulting fractions from advanced distillations were compared to evaporation and burn samples to determine if there were any similarities.

Amyloid Fibril Polymorphism : Structure, Supramolecular Chiraliy And Spontaneous Interconversion, Dzmitry Kurouski

Legacy Theses & Dissertations (2009 - 2024)

Specific protein aggregation has been linked to more than 25 severe human maladies including prion, Alzheimer's, and Parkinson's diseases. These important malfunctions are often referred to as 'conformational' disorders and result from the conversion of a normal isoform of a protein into a specific b-sheet rich polymeric amyloid form. This work elaborates a comprehensive characterization of amyloids and dedicated to the investigation of the fibril polymorphism using advanced microscopic tools, such as Atomic Force and Scanning Electron microcopies, together with several vibrational spectroscopy techniques, such as Raman, Infrared and Vibrational Circular Dichroism. A new type of protein folding-aggregation phenomenon, spontaneous …

Trace Element Analysis Of Environmental And Clinical Materials Using Novel Instrumentation Based On X-Ray Fluorescence Spectrometry : New Capabilities For Public Health Laboratories, Kathryn G. Mcintosh

Legacy Theses & Dissertations (2009 - 2024)

X-ray fluorescence (XRF) spectrometry is a well-established analytical technique for determining the elemental content of many different materials. XRF has long been used for public health applications, particularly for identifying lead-based paint hazards. The primary advantage of XRF over other atomic spectrometric techniques is that it is nondestructive. In addition, little sample preparation is required, so results are obtained rapidly and at low cost. The principal aim of this study was to characterize the utility and reliability of current XRF instrumentation for use in the environmental health sciences. Interest in the use of XRF for detecting lead in children's toys …

Synthesis And Flame Retardant Testing Of New Boronated And Phosphonated Aromatic Compounds, Vladimir Benin, Sravanthi Durganala, Alexander Morgan

Chemistry Faculty Publications

The present report describes the preparation and use of some dimethyl terephthalate derivatives in transition metal-catalyzed coupling reactions to produce new reactive flame retardants. Dimethyl iodoterephthalate and dimethyl 2,5-diiodoterephthalate were successfully employed in the preparation of phosphonic and boronic esters and acids. The latter were tested for heat release with a microcombustion calorimeter (ASTM D7309) to determine the potential for heat release reduction of these flame retardant molecules. The results showed that the addition of boronic or phosphonic acids greatly lowered the heat release, due to a condensed phase (char formation) mechanism. Adding ester groups to the boronic acids or …

Laboratory Methods For The Advancement Of Wastewater Treatment Modeling, Holly E. Gray

Theses and Dissertations (Comprehensive)

To achieve the low levels of total phosphorus required in wastewater treatment plant effluent all chemical forms of phosphorus should be removed. The most refractory phosphorus in terms of removal is so-called “organic phosphorus”. This thesis explores potential relationships between dissolved organic matter and organic phosphorus and methods of removing organic phosphorus from waste water. Fluorescence spectroscopy will be used to characterize dissolved organic matter (DOM) in wastewater. The fluorescent DOM will then be monitored throughout the various wastewater treatment plants to investigate any changes throughout the treatment train. Correlations between fluorophore concentrations (concentrations determined for the different classifications of …

Characterizing Dissolved Organic Matter And Cu2+, Zn2+, Ni2+, And Pb2+ Binding In Salt Water And Implications For Toxicity, Rachael L. Diamond

Theses and Dissertations (Comprehensive)

The binding of metal to dissolved organic matter in aquatic environments is important in controlling the bioavailability and potential toxicity of metals such as Zn²⁺, Pb²⁺, Ni²⁺ and Cu²⁺. The purpose of this research is to: (i) quantify binding capacity to different sources of marine organic matter at environmentally relevant concentrations; (ii) test fluorescence quenching and voltammetric method for use in seawater conditions and; (iii) compare predicted speciation parameters with toxicological observations in the same samples.

Information regarding the solubility of copper and copper compounds is important for risk assessment and can be …

Novel Aromatic Ion–Pairs: Synergy Between Electrostatics And Π-Face Aromatic Interactions, Pramod Prasad Poudel

Theses and Dissertations--Chemistry

This dissertation focuses on the design and study of charged aromatic molecules where weak π-π interactions synergize with electrostatic interactions to enhance the overall interaction between aromatic moieties. Each chapter investigates some aspect of this hypothetical synergy between electrostatics and π-face aromatic cohesion.

The first chapter unveiled the importance of electrostatics in the intramolecular stacking of flexible aromatic molecular templates 1-2Br and 2a. While our previous studies found dicationic molecular template 1-2Br to have intramolecular π-stacking between electron poor pyridinium and electron rich xylylene moieties, no such stacking interaction was observed in the neutral analog 2a.

Chapter two systematically …

Selective Recognition Of H2po4 By A Cholestane-Imidazole-Zinc Ensemble, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim

Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)

A new facile amphiphile cholestane-based zinc complex 4 containing a 3-aminopropylimidazole moiety at the 3a and 7a positions of cholestane was designed and synthesized. Recognition selectivity of the new receptor 4 with various anions was assessed by 1H NMR titration. Dihydrogen phosphate showed the highest binding affinity among all the tested anions

Development Of Spectrophotometric Method For The Determination Of Perindopril Erbumine In Pharmaceutical Formulations Using 2, 4 Dinitrofluorobenzene, Habibur Rahman Dr.

Habibur Rahman

No abstract provided.