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Title: URINALYSIS SCREENING OF DRUGS IN ADULTERATED SAMPLES VIA DIRECT ANALYSIS IN REAL TIME -- HIGH RESOLUTION/ MASS SPECTROMETRY (DART-HR/MS).
Creator: Olivieri, Bianca E, Bridge, Candice, University of Central Florida
Abstract / Description: Current screening methods for drug analysis with urine samples includes examination of the sample with an immunoassay. These methods are used to determine the concentration of drug metabolites contained within the sample prior to further confirmatory testing. Drug testing plays a crucial role in maintaining safe workplace environments and safety of individuals. However, a positive result can lead to heavy consequences for the employee including suspension or removal from the workplace....
Show moreCurrent screening methods for drug analysis with urine samples includes examination of the sample with an immunoassay. These methods are used to determine the concentration of drug metabolites contained within the sample prior to further confirmatory testing. Drug testing plays a crucial role in maintaining safe workplace environments and safety of individuals. However, a positive result can lead to heavy consequences for the employee including suspension or removal from the workplace. Therefore, a majority of individuals add commonly known products into the sample to evade detection by developing a false negative result. Although specimen integrity examinations are performed to identify tampering of the sample, these results are typically biased on the experience of the examiner. The purpose of this study was to develop an analytical screening technique that will detect the drug of interest as well as the presence of any additional products that may be added into the sample via Direct Analysis in Real Time � High Resolution/Mass Spectrometry (DART-HR/MS) which is an ambient ionization source that produces fast mass spectrum results that can provide semi-quantitative information of the target metabolite concentration. Although there are various studies that indicate the ability of the DART to detect drug compounds, there are no known studies that have examined how real-world urine samples are analyzed. Additionally, there are no current studies that take into consideration adulteration of the urine sample using the DART method. The results obtained in the study showed the ability for DART to identify molecular protonated peaks indicative of dextroamphetamine and/or the presence of masking agents. While the other target drugs could not be identified using this method, the identification of dextroamphetamine, adulterant products and the deuterated internal standard show promise in using this as a screening technique prior to confirmatory tests. Future work is currently being conducted to optimize the protocol for the evaluation of THC, cocaine and benzodiazepines.
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Date Issued: 2019
Identifier: CFH2000538, ucf:45623
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000538

Title: DISCRIMINATION OF FORENSIC TRACE EVIDENCE USING LASER INDUCED BREAKDOWN SPECTROSCOPY.
Creator: Bridge, Candice, Sigman, Michael, University of Central Florida
Abstract / Description: Elemental analysis in forensic laboratories can be tedious and many trace evidence items are not analyzed to determine their elemental composition. Presently, scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDS) is the primary analytical tool for determining the elemental composition of trace evidence items. However, due to the time it takes to obtain the required vacuum and the limited number of samples that can be analyzed at any one time, SEM-EDS can be impractical...
Show moreElemental analysis in forensic laboratories can be tedious and many trace evidence items are not analyzed to determine their elemental composition. Presently, scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDS) is the primary analytical tool for determining the elemental composition of trace evidence items. However, due to the time it takes to obtain the required vacuum and the limited number of samples that can be analyzed at any one time, SEM-EDS can be impractical for a high volume of evidence items. An alternative instrument that can be used for this type of analysis is laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). While LA-ICP-MS is a very precise and quantitative analytical method that determines elemental composition based on isotopic mass measurements; however, the instrumentation is relatively expensive and therefore is budgetarily prohibitive for many forensic laboratories. It is the purpose of this research to evaluate an inexpensive instrument that can potentially provide rapid elemental analysis for many forensic laboratories. Laser induced breakdown spectroscopy (LIBS) is an analytical method that meets these requirements and offers information about the elemental composition based on ionic, atomic and diatomic molecular emissions.
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Date Issued: 2007
Identifier: CFE0001957, ucf:47463
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001957

Title: Strategies for Enhanced Genetic Analysis of Trace DNA from Touch DNA Evidence and Household Dust.
Creator: Farash, Katherine, Ballantyne, John, Kolpashchikov, Dmitry, Bridge, Candice, University of Central Florida
Abstract / Description: In forensic casework it is often necessary to obtain genetic profiles from crime scene samples that contain increasingly smaller amounts of genetic material, called Low Template DNA (LTDNA). Two examples of LTDNA sources are touch DNA evidence and dust bunnies. Touch DNA refers to DNA that is left behind through casual contact of a donor with an object or another person. Touch DNA can be used to prove a suspect was present at a crime scene. Dust bunnies, or dust conglomerates, typically...
Show moreIn forensic casework it is often necessary to obtain genetic profiles from crime scene samples that contain increasingly smaller amounts of genetic material, called Low Template DNA (LTDNA). Two examples of LTDNA sources are touch DNA evidence and dust bunnies. Touch DNA refers to DNA that is left behind through casual contact of a donor with an object or another person. Touch DNA can be used to prove a suspect was present at a crime scene. Dust bunnies, or dust conglomerates, typically contain trapped shed skin cells of anyone in the vicinity along with fibers, dirt, hair, and other trace materials. Dust specimens are a potential source of forensic evidence that has been widely underutilized in the forensic community. This is unfortunate because a dust bunny could not only be used to associate a person or crime scene (-) through trace materials such as fibers (-) but also to positively identify (-) through a DNA profile. For example, if a dust specimen is found on a piece of evidence suspected of being moved from its original location, for instance as a body that is too heavy to carry and therefore collects dust while being dragged, then it could be used to link a suspect to a crime scene.Standard methods for obtaining and analyzing touch DNA have been established, but the techniques are not ideal. First, by nature, the 'blind-swabbing' technique, which involves cotton swabs or adhesive tape being applied to an area of interest, can artificially create mixtures of biological material that was originally spatially separated. Second, because the amount of DNA present is typically very low, standard analysis methods may not be sensitive enough to produce probative profiles. In the case of mixtures, the minor component's DNA may go undetected. Dust specimens contain degraded genetic material that has been accumulating for an unknown amount of time. Additionally, dust is usually a conglomeration of genetic material from multiple donors so a mixed profile, if any, is likely to be recovered if standard analysis methods are used.In order to overcome these obstacles presented by LTDNA, a micro-manipulation and combined cell lysis/direct PCR amplification technique has been developed that is sensitive enough to obtain full or probative STR profiles from single or clumped bio-particles collected from touch DNA and dust evidence. Sources of touch DNA evidence such as worn clothing items, touched objects, and skin/skin mixtures are easily sampled using an adhesive material on a microscope slide. Dust specimens can be dispersed onto an adhesive material as well. Targeted bio-particles are then (")picked(") with a water-soluble adhesive on a tungsten needle and deposited into a micro-volume STR amplification mix. Individual selection and analysis of isolated bio-particles reduces the chance of mixed profile recovery. To aid in the release of genetic material present in the bio-particles, a lysis mix containing a thermostable proteinase is then added to the sample. Samples are then analyzed using standard capillary electrophoresis (CE) methods.In addition to identifying the donor source of these LTDNA sources, it would be beneficial to a criminal investigation to identify the tissue source of the biological material as well. While it is widely speculated that the material originates from shed skin cells, there is little confirmatory evidence proving this assertion. Knowledge of the nature of the evidence could be vital to prevent its misinterpretation during the investigation and prosecution of a crime. Here tissue specific mRNA biomarkers have been evaluated for their use in tissue source determination using a highly sensitive High Resolution Melt (HRM) temperature assay that detects the selectively amplified targets based on their melt temperatures.Using the enhanced genetic analysis technique described above, DNA profile recovery has been markedly enhanced in sources of Touch DNA evidence and dust specimens compared to standard methods. Additionally, the molecular-based characterization method could potentially provide a better understanding of the meaningfulness of the recovered DNA profiles. This optimized strategy provides a method for recovering highly probative data from biological material in low template samples in an efficient and cost effect manner.
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Date Issued: 2015
Identifier: CFE0006033, ucf:50979
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006033

Title: Quantitative Assessment of the effects of Microbial Degradation of a Simple Hydrocarbon Mixture.
Creator: Kindell, Jessica, Sigman, Michael, Bridge, Candice, Campiglia, Andres, University of Central Florida
Abstract / Description: Ignitable liquids consist of either a single organic compound or a complex organic mixture. In regards to fire debris analysis, the analyst is responsible for determining if an ignitable liquid residue is present. However, when extracted from soil-containing fire debris evidence, chemical degradation from microorganisms is observed to result in the loss of compounds based on chemical structure. It can also happen when the evidence container is stored at room temperature before analysis. This...
Show moreIgnitable liquids consist of either a single organic compound or a complex organic mixture. In regards to fire debris analysis, the analyst is responsible for determining if an ignitable liquid residue is present. However, when extracted from soil-containing fire debris evidence, chemical degradation from microorganisms is observed to result in the loss of compounds based on chemical structure. It can also happen when the evidence container is stored at room temperature before analysis. This can present a challenge to the fire debris analyst when identifying and classifying the ignitable liquid residue based on the criteria established by standard test methods. The purpose of this research was to observe the microbial degradation of fourteen compounds, at room temperature over a period of time, for possible by-product formation that could coincide with compounds normally present in an ignitable liquid. Additionally, a quantitative assessment was performed to observe and record the loss rate of compounds in a representative simple mixture. Finally, the loss rate from the simple mixture was compared to commercially available ignitable liquids. Degradation studies were conducted to observe the microbial degradation of a representative compounds (individually and in a simple mixture, both weathered and unweathered) and seven ignitable liquids of different ASTM E1618 classifications. Potting soil was spiked with 20 (&)#181;L of a liquid/compound and was allowed to stand at room temperature for a period of time. The simple mixture was evaporated to 50% and 90% using a steady nitrogen gas flow to compare the degradation process to the unweathered mixture. All samples were extracted and analyzed using passive-headspace concentration and gas chromatography-mass spectrometry.The formation of by-products was not observed when degrading the compounds from the simple mixture individually as seen in other research. The simple mixture, unweathered and 50% weathered, resulted in rapid degradation of their oxygenated compounds. The straight-chained alkanes and toluene were observed to be more susceptible to microbial attack than the highly-substituted aromatics and the branched and cyclic alkanes. The 90% weathered mixture followed the same degradation trend as the unweathered and 50% weathered samples, although it only contained two compounds. The loss rates/half-lives for each simple mixture sample (unweathered, 50% weathered, and 90% weathered) were determined to be approximately 3.5, 3.5, and 0.84 days. The unweathered and 50% weathered sample half-lives were similar due to containing compounds with similar susceptibility to degradation, while the 90% weathered sample contained one compound that was more highly susceptible to degradation. When comparing the 3.5 day half-life to the seven different ASTM class liquids, the isoparaffinic product and the naphthenic-paraffinic product had similar rates of degradation while aromatic solvent and normal alkane classes had the shortest half-lives. When observing the degradation of the gasoline, medium petroleum distillate and the miscellaneous, the constituent compounds were seen to exhibit a range of degradation rates that corresponded to half-lives less than and greater than 3.5 days.
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Date Issued: 2015
Identifier: CFE0005966, ucf:50817
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005966

Title: Development of Molecularly Imprinted Polymers for Forensic Applications.
Creator: Martinez, Sara, Sigman, Michael, Bridge, Candice, Yestrebsky, Cherie, University of Central Florida
Abstract / Description: In some forensic disciplines various methods of extraction are used to perform analysis. Among these methods, solid phase extraction (SPE) and solid phase microextraction (SPME) are used in fields such as toxicology and explosives analysis. To enhance extraction efficiency in SPE and SPME, molecularly imprinted polymers (MIPs), which are designer polymers, can be more selective for the binding of an analyte or group of analytes that are similarly structured. Separation of analytes from...
Show moreIn some forensic disciplines various methods of extraction are used to perform analysis. Among these methods, solid phase extraction (SPE) and solid phase microextraction (SPME) are used in fields such as toxicology and explosives analysis. To enhance extraction efficiency in SPE and SPME, molecularly imprinted polymers (MIPs), which are designer polymers, can be more selective for the binding of an analyte or group of analytes that are similarly structured. Separation of analytes from complex mixtures is possible by utilizing these polymers. This may be especially useful in forensic applications where sample sizes may be small and composition may be complex. In this work, MIP solid phase microextraction fibers (MIP-SPME) were fabricated and caffeine was selectively sampled in the presence of theophylline and theobromine. Calibration studies were performed using the MIP-SPME to quantitate the concentration of caffeine in teas and coffees. MIP-SPME fibers were also prepared with 2,4-dinitrotoluene and deuterated 2,6-dinitrotoluene. Less selectivity was obtained for extraction of 2,4-DNT and 2,6-DNT in the presence of other DNT isomers. Fabricated blank polymers extracted analytes at the same response as templated polymers for both caffeine and DNT, despite expected results. MIP-SPE columns were also fabricated using deuterated 2,6-DNT to determine if changing the extraction procedure would increase extraction selectivity. Using different solvents in the extraction procedure changed the extraction performance efficiency of the MIPs due to the change in solvent polarity. All samples were analyzed using gas chromatography mass spectrometry.
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Date Issued: 2016
Identifier: CFE0006477, ucf:51423
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006477

Title: Classification of Silicone-Based Personal and Condom Lubricants Using DART-TOFMS.
Creator: Harvey, Lauren, Bridge, Candice, Sigman, Michael, Campiglia, Andres, Yestrebsky, Cherie, University of Central Florida
Abstract / Description: Sexual lubricants are used to enable sexual encounters. There are different types of sexual lubricants such as water-based, oil-based, and silicone-based. They come pre-applied to condoms and separately in bottles as personal lubricants. Although sexual lubricants are intended for consensual use, they are also unfortunately used during the commission of sexual assaults. The analysis of sexual lubricants facilitates sexual assault investigations. With the increased usage of condoms in sexual...
Show moreSexual lubricants are used to enable sexual encounters. There are different types of sexual lubricants such as water-based, oil-based, and silicone-based. They come pre-applied to condoms and separately in bottles as personal lubricants. Although sexual lubricants are intended for consensual use, they are also unfortunately used during the commission of sexual assaults. The analysis of sexual lubricants facilitates sexual assault investigations. With the increased usage of condoms in sexual assault cases, the potential of collected DNA evidence in each case is reduced. In the absence of biological evidence, the presence of sexual lubricants after a sexual assault can provide an additional link between a suspect and the crime scene and/or victim. Having the ability to compare known and unknown sexual lubricants may be the only actionable information available for investigators. Current lubricant analysis only classifies samples into lubricant types based on the major component such as glycerol, petrolatum, and polydimethylsiloxane for water-based, oil-based, and silicone-based lubricants respectively. Differentiation within major types has not been explored. Previously, protocols have been developed to detect and categorize personal lubricants using Fourier transform infrared (FTIR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), liquid chromatography mass spectrometry (LC-MS), and pyrolysis GC-MS. FTIR is routinely used as a screening tool to detect peaks of the major lubricant components and the mass spectrometry (MS) techniques are commonly used to confirm the presence of some of the major components, excluding PDMS.This thesis focused on the differentiation of silicone-based personal and condom lubricants because it is a common type of lubricant due to its ability to reduce friction for a longer period of time. Fifty-six (56) silicone personal and condom lubricants were analyzed to identify unique characteristics that can be used to determine individual sub-classes and test those sub-classes. Direct analysis in real time-time of flight mass spectrometry (DART-TOFMS) was utilized because minor and unique molecular ions that could be attributed to different sub-groups can easily be distinguished from the major sample peaks. This is primarily based on the direct mass spectrometry design of the instrumentation that can differentiate minor components from major components that might not be observed using traditional chromatographic separation. The DART source creates molecular ions for individual components in mixed samples under atmospheric conditions in either positive or negative mode. The TOF-MS, which is capable of high resolution and accurate mass analysis, allows more accurate and precise detection of molecular component ions. Additionally, no sample preparation is required to analyze neat samples, which minimizes potential contamination issues. Attenuated total reflectance-FTIR (ATR-FIR) was used to analyze the training set personal lubricants to compare previous methods of analysis to the newly developed DART-TOFMS method of analysis.Principle component analysis (PCA) and cluster analysis were used to identify potential sub-groups and subsequently a classification scheme. Linear discriminant analysis was utilized to conduct leave one out cross validation and to categorize test samples. Eight sub-groups were developed based on the presence and/or absence of PDMS and minor component peaks observed.A classification scheme was developed using the eight sub-groups identified through PCA and cluster analysis. This classification scheme was tested using LDA to classify blind samples. One group includes a scented personal lubricant. Another group includes flavored condom lubricants. The other groups were developed based on the relative intensity of PDMS peaks and minor component peaks. Variation of the intensity of PDMS peaks between and within samples of different lot numbers causes some misclassification of samples. This classification scheme also doesn't take into account real-world factors such as dilution and biodegradation. Although further research is required to create a more stable classification scheme, the identified sub-groups are a good foundation for the creation of a lubricant database and finalized classification scheme.
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Date Issued: 2016
Identifier: CFE0006459, ucf:51415
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006459

Title: Characterization of Post-Fire Priming Cup Residue Using Scanning Electron Microscopy Coupled With Energy Dispersive X-Ray Spectrometry.
Creator: Terry, Molly, Bridge, Candice, Sigman, Michael, Campiglia, Andres, University of Central Florida
Abstract / Description: Ammunition is most often comprised of a lead-based priming mixture which contributes to the traditional characteristics of gunshot residue (GSR). Due to the health risks often associated with lead, lead-free primer alternatives are becoming increasingly more popular. Thus, it is becoming more difficult to determine the presence of GSR based on traditional means, i.e. the presence of lead (Pb), barium (Ba), and antimony (Sb). Eight different ammunitions were purchased which consisted of one...
Show moreAmmunition is most often comprised of a lead-based priming mixture which contributes to the traditional characteristics of gunshot residue (GSR). Due to the health risks often associated with lead, lead-free primer alternatives are becoming increasingly more popular. Thus, it is becoming more difficult to determine the presence of GSR based on traditional means, i.e. the presence of lead (Pb), barium (Ba), and antimony (Sb). Eight different ammunitions were purchased which consisted of one lead-based and one lead-free from four different manufacturers, including Winchester, Federal, Liberty, and Sellier (&) Bellot. Half of the rounds from each manufacturer and chemical composition (i.e. lead-based or lead-free) were disassembled, e.g. the projectile and smokeless powder were removed, leaving the priming cup in place (i.e. primed only). The remaining cartridges were left intact (i.e. full cartridge). Both the full cartridges and the primed only cartridges for each ammunition were fired using a 9mm Glock and the cartridges were collected post-fire, and subsequently deprimed. Five cups and five anvils from each type of ammunition were adhered to aluminum stubs via colloidal graphite. The GSR remaining on the anvils and in the cups was then analyzed using scanning electron microscopy coupled with energy dispersive x-ray spectrometry (SEM-EDX). Three spectra were collected for each anvil and each cup resulting in 30 total spectra per type of ammunition. The primary element peaks were then selected and four different dataset matrices were created for the full cartridge anvils, full cartridge cups, primed only anvils, and primed only cups. The data was processed using unit vector normalization and was then analyzed using principal component analysis (PCA) and linear discriminant analysis (LDA) to determine the characterization between lead-free and lead-based ammunition. The anvils provided better separation and characterization based on the ability to better collect x-rays, and therefore demonstrated the capability of the ammunition to cluster by both primer mixture composition and manufacturer. The lead-based and lead-free primers showed consistencies across samples, such as the presence or absence of K, which allowed for characterization based on primer composition.
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Date Issued: 2016
Identifier: CFE0006509, ucf:51377
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006509

Title: Optimizing Laboratory Pyrolysis Methods to Compliment Real World Fire Debris.
Creator: Coulson, Richard, Sigman, Michael, Bridge, Candice, Yestrebsky, Cherie, Campiglia, Andres, University of Central Florida
Abstract / Description: Forensic analysts are tasked with determining the presence of ignitable liquid residue in fire debris. Analysis of fire debris allows the analyst to understand how the fire occurred. However, the presence of some substrates can potentially impact the identification of ignitable liquid residue and classification of a sample as positive or negative for the presence of ignitable liquid. Pyrolysis of building materials and furnishings (substrates) lead to background interference within the...
Show moreForensic analysts are tasked with determining the presence of ignitable liquid residue in fire debris. Analysis of fire debris allows the analyst to understand how the fire occurred. However, the presence of some substrates can potentially impact the identification of ignitable liquid residue and classification of a sample as positive or negative for the presence of ignitable liquid. Pyrolysis of building materials and furnishings (substrates) lead to background interference within the resulting chromatographic profile. To combat misclassification of a sample as positive for ignitable liquid residue, knowledge of the pyrolysis products from individual substrates is of utmost importance. However, unburned reference samples from a fire scene can be difficult to obtain. The use of a database in conjunction with the analysis of the samples can lead to a more complete analysis of fire debris. Within this research, four different burn methods (modified destruction distillation method, top heat, bottom heat, and tube furnace) were utilized in burning eight different flooring substrates (polyester, nylon, and olefin carpeting, carpet padding, vinyl flooring, laminate flooring, yellow pine, and plywood) to obtain pyrolysis/combustion product profiles. Each burn method was performed at three different burn times for a total of twelve different burns of each substrate. Standard methods, ASTM E1412-12 and ASTM E1618-14, were used in the extraction and interpretation of the laboratory burn products. Principal component analysis (PCA) was used to relate the laboratory burn results to neat ignitable liquid/substrate and large scale burn data sets.Laboratory burn data projected into the PCA space displayed that the laboratory burn data is similar to the data contained within the ILRC and Substrate databases. Differences observed within laboratory burn data projections illustrated the variability of the laboratory burn methods. The composition of the substrate dictated the pyrolysis/combustion products produced. While this research only focuses on flooring substrates, an increase in the number of different types of materials in the Substrate Database can aid analysts in identifying common pyrolysis/combustion products observed in fire debris.
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Date Issued: 2017
Identifier: CFE0006578, ucf:51357
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006578

Title: In situ Treatment Systems for Remediation of Polychlorinated Biphenyl-contaminated building materials.
Creator: Almutairi, Adibah, Yestrebsky, Cherie, Beazley, Melanie, Legron-Rodriguez, Tamra, Bridge, Candice, Randall, Andrew, University of Central Florida
Abstract / Description: Polychlorinated Biphenyls (PCBs) are a family of synthetic organohalides comprising 209 congeners which were used historically as additives in paint and caulking materials over a span of many years. Even though the production of PCBs in the USA has been banned since the late 1970s, their former prevalence and widespread use means many structures are still coated with PCB-laden paints. In addition, the presence of PCBs in elastic sealants has resulted in transport of PCBs into concrete...
Show morePolychlorinated Biphenyls (PCBs) are a family of synthetic organohalides comprising 209 congeners which were used historically as additives in paint and caulking materials over a span of many years. Even though the production of PCBs in the USA has been banned since the late 1970s, their former prevalence and widespread use means many structures are still coated with PCB-laden paints. In addition, the presence of PCBs in elastic sealants has resulted in transport of PCBs into concrete structures and has caused soil contamination around buildings. PCB-contaminated building materials have become a significant concern for the environment and building occupants due to their carcinogenic nature and potential indoor contamination. This results in an urgent need for development of a cost-effective method to extract and degrade PCBs from contaminated materials. Experiments employing reductive dehalogenation through the use of zero-valent magnesium (ZVMg) ball-milled with activated carbon (AC) in an acidified solvent system have shown that PCBs can be broken down even in the presence of water. This research describes the development of two delivery systems for effective deployment of this treatment reaction to field samples. Two treatment systems formulated in this process, the Non-Metal Treatment System (NTMS) and the Activated Metal Treatment System (AMTS), are capable of extracting or extracting and degrading, respectively, trapped PCBs within a variety of building materials. In the development of NMTS and AMTS, an acidified dual system of ethanol/ethyl lactate was used as solvent while ZVMg over activated carbon is used in the AMTS. After development, applications of the systems extended to laboratory prepared PCB-laden paint as well as field samples received from Seattle. A marked successful on PCB remediation was observed. The green solvent 2-butoxyethanol is approved by both the EPA and the FDA, and is an interesting alternative for the dechlorination of PCBs. Novel versions of NMTS and AMTS were developed by substituting 2-butoxyethanol for ethanol/EL and used on a set of paint chips and building materials from the same field site. PCBs were degraded significantly below their starting concentrations with removal efficiency greater than 99% for all samples after two weeks of treatment. The use of acidified 2-butoxyethanol and ZVMg permitted the extraction and destruction of PCBs from contaminated building materials in a one-step treatment. Additional studies were conducted on laboratory-prepared concrete where transport of the organic solvents (used in development of NMTS/AMTS) into the concrete structure was studied. PCB concentrations in concrete after treatment were reduced to below the limit of detection.
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Date Issued: 2018
Identifier: CFE0007388, ucf:52064
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007388

Title: Novel Fuel-producing Fungi and Methodologies for Increasing Fuel Production.
Creator: Wang, Yuemin, Harper, James, Bridge, Candice, Frazer, Andrew, Beazley, Melanie, Blair, Richard, University of Central Florida
Abstract / Description: An endophytic fungus Hypoxylon sp. (BS15) has recently been isolated and found to produce volatile organic compounds (VOCs) that have potential relevance as hydrocarbon fuels. In the work described here, the traditional refined carbohydrate (e.g., sucrose) diet source was replaced by simple sugars produced using a solvent free green chemistry mechanocatalytic method involving ball milling in the solid. BS15 is able to grow on this degraded cellulose as well as the more traditional potato...
Show moreAn endophytic fungus Hypoxylon sp. (BS15) has recently been isolated and found to produce volatile organic compounds (VOCs) that have potential relevance as hydrocarbon fuels. In the work described here, the traditional refined carbohydrate (e.g., sucrose) diet source was replaced by simple sugars produced using a solvent free green chemistry mechanocatalytic method involving ball milling in the solid. BS15 is able to grow on this degraded cellulose as well as the more traditional potato dextrose broth. The volatile compounds produced from both media were largely the same. Unfortunately, it is observed that long term in vitro growth of BS15 results in diminished VOC production. The VOC production was partially restored by cultivating BS15 in growth media containing finely ground woody tissue from the original host plant (Taxodium distichum). Extracts from this woody tissue were made by sequentially extracting with dichloromethane, methanol, and water with a goal of isolating VOC production modulators. Both the dichloromethane and water extracts place on bio-mimicking filter paper were found to modulate VOC production, while the methanol extract had no significant impact. Surprisingly, the woody tissue remaining after exhaustive extraction also acted as a VOC production modulator when combined with the growth media, with noticeable changes in the production of four compounds. This woody tissue also induced production of two compounds not observed in the original BS15 extract, and their changes are inheritable. Remarkably filter paper had the same modulating effect as exhaustively extracted woody tissue, suggesting the modulation was partially due to cellulose degradation products. Extraction of the maximum amounts of VOCs is desirable and here a comparison of solid phase extraction (SPE) and solid phase micro-extraction (SPME) techniques is made. This comparison involves two endophytes, BS15C and Streptomyces ambofaciens (SA 40053). The SPE technique is more effective in retaining compounds having lower vapor pressures and higher boiling points with nearly three to five times more VOC mass obtained versus SPME.
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Date Issued: 2019
Identifier: CFE0007552, ucf:52598
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007552

Title: The Characterization of Condom Lubricants and Personal Hygiene Products using DART-TOFMS and GC- MS and The Investigation of Gold Nanoparticle Behavior in Water and the Interaction with Blood Serum Proteins.
Creator: Moustafa, Yasmine, Huo, Qun, Bridge, Candice, Sigman, Michael, Baudelet, Matthieu, Popolan-Vaida, Denisia, Ni, Liqiang, University of Central Florida
Abstract / Description: This dissertation is divided into two independent research projects. First, condom lubricants, sexual lubricants, and personal hygiene products (PHPs) were studied using direct analysis in real time-time-of-flight-mass spectrometry (DART-TOFMS) and gas chromatography-mass spectrometry (GC-MS). The purpose addressed the concern of perpetrators resorting to new tactics, i.e. using condoms to remove seminal fluid that could provide a DNA link to a suspect, leading to the need of the...
Show moreThis dissertation is divided into two independent research projects. First, condom lubricants, sexual lubricants, and personal hygiene products (PHPs) were studied using direct analysis in real time-time-of-flight-mass spectrometry (DART-TOFMS) and gas chromatography-mass spectrometry (GC-MS). The purpose addressed the concern of perpetrators resorting to new tactics, i.e. using condoms to remove seminal fluid that could provide a DNA link to a suspect, leading to the need of the consideration of condom lubricants as pieces of sexual assault evidence. Due to condom lubricants having a chemical composition resembling PHPs, the investigation of both sample groups was analyzed to prevent false positives. Although past research has focused on the identification of major lubricant groups and additives, the discernment between such samples is insufficient. The discriminatory capability and rapid analysis of samples using DART-TOFMS was illustrated through resolution among the sample groups and higher classification rates. Here, lubricant analysis was introduced as a viable source of evidence, with a scheme detailing their discrimination from common hygiene products using DART-TOFMS as a robust tool for the analysis of sexual assault evidence. Second, gold nanoparticles (AuNPs) were characterized using dynamic light scattering (DLS), Ultraviolet-Visible spectroscopy (UV-VIS), dark field Imaging (DFM), and Transmission electron microscopy (TEM). Following characterization, AuNPs were used in protein adsorption study from blood serum concentration and to observe how the differences in their characterization affected their interactions with blood serum proteins. AuNPs are an interest in the bioanalytical sector due to their optical properties, scattering of light, and high surface-to-volume ratio. A common issue plagues the field: the difficulty of inter/intra laboratory reproducibility from one characterization technique. This further affects the understanding of how AuNPs may react for diagnostic and other applications. The importance of a comprehensive characterization protocol for AuNP products and the need for manufacturers to include product specifications is demonstrated in this study.
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Date Issued: 2019
Identifier: CFE0007842, ucf:52814
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007842

Characterization (2)	+ -
DART-TOFMS (2)	+ -
fire debris (2)	+ -
forensic science (2)	+ -
(Solid phase microextraction) SPME (1)	+ -

04/02/2018 (1)	+ -
Adulterants (1)	+ -
Blood(serum) Absorption Study (1)	+ -
Chemometrics (1)	+ -
Classification (1)	+ -
Condoms (1)	+ -
DART (1)	+ -
DLS (1)	+ -
Dinitrotoluene (DNT) isomers (1)	+ -
Drug Testing (1)	+ -
Dust (1)	+ -
ELISA (1)	+ -
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