Other Chemistry Commons^™

Aptamer-Based Voltammetric Biosensing For The Detection Of Codeine And Fentanyl In Sweat And Saliva, Rosa Lashantez Cromartie

FIU Electronic Theses and Dissertations

Despite the many governmental and medicinal restrictions created to combat the opioid epidemic in the United States, opioid abuse and overdose rates continue to rise. The development of an aptamer-based voltammetric sensor and biosensor is described in this dissertation. The aim was to develop a low-cost, sensitive, and specific aptamer-based sensor for on-site, label-free determination of codeine and fentanyl in biological fluids. To do this, the surfaces of screen-printed carbon electrodes (SPCE) were modified with gold nanoparticles (AuNPs), followed by the addition of single-stranded DNA aptamers. These were covalently bound to the electrode surface. Operations of the sensors were collected …

The Development Of A Surface Enhanced Raman Spectroscopy Method For The Detection Of Synthetic Cannabinoids In Urine, Thaddeus Mostowtt

FIU Electronic Theses and Dissertations

The use and abuse of synthetic cannabinoids has increased significantly in recent years due to their easy access and growing popularity. Despite having more known drugs become illegal, new synthetic versions of these drugs are being made that have not yet been recognized or classified as illegal substances. Therefore, standard methods may not be able to detect these drugs.

The most common method of screening detection for drugs of abuse in biological samples is the immunoassay. However, the immunoassay method presents some disadvantages, particularly for newly synthesized compounds. More advanced methods have also been used, such as LC-MS; however, these …

Systematic Comparison Of Pre-Treatment Parameters In Forensic Hair Analysis And Investigating Hair-Drug Interactions, Jennett Chenevert Aijala

FIU Electronic Theses and Dissertations

Forensic toxicological analysis for the purposes of protecting human health and supporting criminal justice activities can be achieved, in part, by means of analysis of human head hair for detection of abused substances. Hair is considered an alternative sample matrix (compared to blood and urine) because of persistent interpretive challenges caused by a lack of standardization in analytical approaches and poor understanding of the biases resulting from physicochemical interactions between major hair components (e.g., melanin) and drugs of abuse. Some of the uncertainty regarding optimal techniques for the pre-treatment of hair specimens results from the unknown nature of the …

Forensic Toxicological Screening And Confirmation Of 800+ Novel Psychoactive Substances By Lc-Qtof-Ms And 2d-Lc Analysis, Melanie N. Eckberg

FIU Electronic Theses and Dissertations

Novel psychoactive substances (NPS) represent a great challenge to toxicologists due to the ability of illicit drug manufacturers to alter NPS chemical structures quickly and with ease to circumvent legislation regulating their use. Each time a new structure is introduced, there is a possibility that it has not been previously recorded in law enforcement or scientific databases. Many toxicology laboratories use targeted analytical methods that rely on libraries of known compounds to identify drugs in samples. However, these libraries do not include large numbers of NPS which could result in non-identification or detection.

High-resolution mass spectrometry (HRMS) has been suggested …

Qualitative Detection Of Selected Designer Drugs And Relevant Metabolites In Environmental Water Samples, Marley Pruyn

FIU Electronic Theses and Dissertations

Designer drugs are compounds which have been synthetically derived from illicit drugs. After consumption, drugs and their metabolites are introduced into the sewage water which is treated and disposed into the environment. A combined target, suspect and non-target workflow was created to detect designer drugs in environmental water samples. Multiple water samples were spiked with an unknown mixture of drugs and metabolites to assess the efficiency of the method. Samples were collected from sewage influent and effluent pipes, downstream from a sewage outfall and reclaimed water. Analysis was conducted with high resolution MS using the QExactive Orbitrap. Screening was performed …

Determination Of Human Scent Biomarkers For Race, Ethnicity And Gender, Lauren J. Colόn Crespo

FIU Electronic Theses and Dissertations

Human scent has been the focal point of diverse scientific interests and research initiatives for the past several years. The knowledge gained about its composition has favored the advancement of multiple disciplines, and promoted the development of a wide variety of applications. Among these applications is the use of human scent as a resource for Forensic investigations, where scent profiles are often used as evidence to associate individuals to the scene of a crime. The characteristic nature of individual human scent has enabled this type of evidence to be used as a biometric tool for the differentiation of subjects. Nevertheless, …

Mangiferin As A Biomarker For Mango Anthracnose Resistance, Herma Pierre

FIU Electronic Theses and Dissertations

Mangos (Mangifera indica L.) are tropical/subtropical fruits belonging to the plant family Anacardiaceae. Anthracnose is the most deleterious disease of mango both in the field and during postharvest handling. It is most commonly caused by the Colletotrichum gloeosporioides complex. Mangiferin, a xanthanoid compound found in at least twelve plant families worldwide (Luo et al., 2012), is present in large amounts of the leaves and edible mangos. Even though this compound plays a pivotal role in the plant’s defense against biotic and abiotic stressors, no correlations been made between the compound and mango anthracnose resistance.

Mangos were collected, grouped …

Development Of A Surface-Enhanced Raman Spectroscopy Method For The Detection Of Benzodiazepines In Urine, Erika L. Doctor

FIU Electronic Theses and Dissertations

Benzodiazepines are among the most prescribed compounds for anti-anxiety and are present in many toxicological screens. These drugs are also prominent in the commission of drug facilitated sexual assaults due their effects on the central nervous system. Due to their potency, a low dose of these compounds is often administered to victims; therefore, the target detection limit for these compounds in biological samples is 10 ng/mL. Currently these compounds are predominantly analyzed using immunoassay techniques; however more specific screening methods are needed.

The goal of this dissertation was to develop a rapid, specific screening technique for benzodiazepines in urine samples …

Development Of Presumptive And Confirmatory Analytical Methods For The Simultaneous Detection Of Multiple Improvised Explosives, Kelley L. Peters

FIU Electronic Theses and Dissertations

In recent years, there has been a dramatic increase in the use of improvised explosive devices (IEDs) due to ease of synthesis and improved controls placed on commercial/military explosives. Commonly used materials for IED preparations include fertilizers and industrial chemicals containing oxidizers such as ClO₃^-, ClO₄^-, and NO₃^-, as well as other less stable compounds, such as peroxides. Due to these materials having a wide range of volatility, polarity, and composition, detection can be challenging, increasing the amount of time before any analytical information on the identity of the explosive can …

Method Development For The Analysis Of Smokeless Powders And Organic Gunshot Residue By Ultra Performance Liquid Chromatography With Tandem Mass Spectrometry, Jennifer L. Thomas

FIU Electronic Theses and Dissertations

The goal of this project was to develop a rapid separation and detection method for analyzing organic compounds in smokeless powders and then test its applicability on gunshot residue (GSR) samples. In this project, a total of 20 common smokeless powder additives and their decomposition products were separated by ultra performance liquid chromatography (UPLC) and confirmed by tandem mass spectrometry (MS/MS) using multiple reaction monitoring mode (MRM). Some of the targeted compounds included diphenylamines, centralites, nitrotoluenes, nitroglycerin, and various phthalates. The compounds were ionized in the MS source using simultaneous positive and negative electrospray ionization (ESI) with negative atmospheric pressure …