Physical Sciences and Mathematics 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 …

Characterization Of Biological Samples Using Multi-Modal Mass Spectrometry, Yarixa L. Cintron-Diaz

FIU Electronic Theses and Dissertations

There is a need for fast, accurate and cost-effective protocols capable of assessing biomolecules at the molecular level (e.g., proteins, lipids and metabolites) from biological specimens. Mass spectrometry (MS) based techniques have become the analytical gold standard for identification and characterization of biomarkers in biological samples. The high throughput and short analysis time scales enables to follow biological processes while providing detailed chemical and spatial characterization. One of the current challenges in biological MS, is the high molecular complexity, chemical diversity and dynamic range. In this dissertation, the use of multi-modal mass spectrometry workflows -mass spectrometry imaging and ion mobility …

Non-Target Analysis Using High-Resolution Mass Spectrometry To Characterize And Remediate Urban Waters, Brian Ng

FIU Electronic Theses and Dissertations

The first part of this dissertation will focus on the development of a simple, robust online solid phase extraction liquid chromatography high resolution mass spectrometry (SPE LC-HRMS) method followed by the use of computational software workflows for non-target analysis (NTA) of environmental samples (development). The benchmarks to assess reproducibility are not well defined for non-target analysis. Parameters to evaluate analytical performance, such as accuracy, precision and selectivity, are well defined for target analysis, but remain elusive for non-target screening analysis. In this study, quality control (QC) guidelines are proposed to assure reliable data in NTA methodologies using a simple …

Ligands For Complexation, Extraction, And Sensing Of Mercury(Ii) For Application To High-Level Waste (Hlw) At The Savannah River Site (Srs), Adenike O. Fasiku

FIU Electronic Theses and Dissertations

Mercury (Hg) separation and sensing is of high significance due to Hg^(II) environmental mobility and toxicity. Furthermore, the use of Hg in nuclear applications has resulted in its accumulation in several DOE sites, such as in Oak Ridge and Savannah River reservations. Organic mercury species have been found in low activity waste (LAW) streams resulting from high-level waste (HLW) processing at the Savannah River Site (SRS), therefore posing a threat to humans and the environment. Mercury, being a soft Lewis acid, has a strong affinity for softer Lewis bases, such as S- or N-donor ligands. Therefore, we focus on …

Utilizing Headspace Solid-Phase Microextraction For The Characterization Of Volatile Organic Compounds Released From Contraband And Its Implications For Detector Dog Training, Kelvin Joseph Frank Jr

FIU Electronic Theses and Dissertations

Improving the accuracy and reliability of odor detection dogs is of utmost importance particularly for legal reasons. Field testing in conjunction with headspace analysis of volatile organic compounds (VOCs) has in recent times allowed for these improvements, by providing scientifically based recommendations for optimum training protocols. The current project leveraged on these established capabilities to enhance three areas of odor detection: illicit drugs, explosives and mass storage devices.

With hemp being legalized under the 2018 Farm Bill, legal questions have been raised regarding a dog’s ability to ignore hemp if trained to detect marijuana, as both are types of Cannabis …

Evaluation Of Harvesting Time For Industrial Hemp (Cannabis Sativa L,) Pilot Project Varieties Grown In South Florida, Jordan W. Prats

FIU Electronic Theses and Dissertations

A field study was conducted to observe the natural development of cannabinoids in three daylength sensitive industrial hemp varieties Bubba Kush (BK), Emerald Flower (EF), and Golden Sunset (GS). Plants were configured in a randomized block design with 3 replications. Once 50% of the plants within a variety reached reproductive growth, plants were sampled weekly until senescence and analyzed through a HPLC-UV/DAD. The results from the study indicate that all three varieties of industrial hemp tested in field study reached reproductive growth within the first week of transplanting. This is due to a 12-hour day-length at the time and the …

Competitive Reductive Removal Of Chromate And Pertechnetate Via Zero-Valent Iron, Jonathan Williams Ramirez

FIU Electronic Theses and Dissertations

Treatment to immobilize radioactive waste is of concern for long-term storage, avoiding future environmental exposure. Most production of Technetium-99 (⁹⁹Tc) occurred as a byproduct of development of legacy nuclear weapons research. Zero-valent iron (ZVI) is a promising reductant of Tc(VII) to a less mobile ⁹⁹Tc(IV). However, more redox-sensitive contaminants can compete in the reductive process. Therefore, it is important to examine the effects of competitive contaminants and quantify the effects on the reductive removal rates of ⁹⁹Tc. Chromate, Cr(VI), is a redox-sensitive contaminant that is expected to be present in legacy waste present in the Hanford …

Uranium Fate And Mineral Transformations Upon Remediation With Ammonia (Nh3) Gas, Silvina A. Di Pietro

FIU Electronic Theses and Dissertations

The fission of uranium (U) for plutonium production was a major activity at the U.S. Department of Energy’s (DOE) Hanford Site in Washington State during World War II and Cold War. This endeavor resulted in the generation of over two million liters of high-level radioactive waste, most of which still remains in 177 underground storage tanks. Due to the improper storage and aging of these tanks in addition to other waste releases across the Site, approximately 200,000 kg of U have been released into the vadose zone. The objective of this study was to determine whether the application of the …