View All Items
(1 - 5 of 5)
- Title
- DEVELOPMENT OF NOVEL DART™ TOFMS ANALYTICAL TECHNIQUES FOR THE IDENTIFICATION OF ORGANIC CONTAMINATION ON SPACEFLIGHT-RELATED SUBSTRATES AND AQUEOUS MEDIA.
- Creator
-
Loftin, Kathleen, Clausen, Christian, University of Central Florida
- Abstract / Description
-
ABSTRACT Organic contamination on spaceflight hardware is an ongoing concern for spaceflight safety. In addition, for the goal of analyzing for possible evidence of extra-terrestrial life, it is necessary to consider the presence of terrestrial contamination. This paper will introduce and evaluate a new method using a direct analysis real time (DART™) ionization source paired with a high resolution time of flight mass spectrometer (TOFMS) for the determination of organic contamination...
Show moreABSTRACT Organic contamination on spaceflight hardware is an ongoing concern for spaceflight safety. In addition, for the goal of analyzing for possible evidence of extra-terrestrial life, it is necessary to consider the presence of terrestrial contamination. This paper will introduce and evaluate a new method using a direct analysis real time (DART™) ionization source paired with a high resolution time of flight mass spectrometer (TOFMS) for the determination of organic contamination involved in spaceflight hardware and ground support materials. This novel analytical technique has significant advantages over current methodologies. Materials analyzed in this study were historically considered as probable contaminants in spaceflight related substrates. A user determined library was generated due to the non-traditional mass spectra generated by the DART™. Continual improvement of analytical methods for the detection of trace levels of contaminants in potential drinking water sources is of extreme importance to both regulatory communities and concerned citizens. This paper will evaluate a novel analytical method using stir bar sorbtive (SBSE) extraction techniques combined with analysis with a DART™TOFMS. Compounds of interest will include several representative pharmaceutical contaminants of emerging concern listed in EPA method 1694. Optimal SBSE and DART™ experimental parameters will be investigated along with accuracy, precision, limits of detection and calibration linearity.
Show less - Date Issued
- 2009
- Identifier
- CFE0002714, ucf:48187
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002714
- 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.
Show less - Date Issued
- 2019
- Identifier
- CFH2000538, ucf:45623
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000538
- 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.
Show less - Date Issued
- 2016
- Identifier
- CFE0006459, ucf:51415
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006459
- 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.
Show less - Date Issued
- 2019
- Identifier
- CFE0007842, ucf:52814
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007842
- Title
- Maya Use and Prevalence of the Atlatl: Projectile Point Classification Function Analysis from Chich(&)#233;n Itz(&)#225;, Tikal, and Caracol.
- Creator
-
Ciofalo, Andrew, Chase, Arlen, Chase, Diane, Barber, Sarah, University of Central Florida
- Abstract / Description
-
Multiple scholars have briefly discussed the Maya use of the atlatl. Yet, there has never been a decisive encompassing discussion of prevalence and use of the atlatl in the Maya region with multiple lines of support from iconographic and artifactual analyses. This thesis explores the atlatl at Chich(&)#233;n Itz(&)#225;, Tikal, and Caracol Maya sites to prove that atlatl prevalence can be interpreted primarily based on projectile point (")classification function(") analysis with support from...
Show moreMultiple scholars have briefly discussed the Maya use of the atlatl. Yet, there has never been a decisive encompassing discussion of prevalence and use of the atlatl in the Maya region with multiple lines of support from iconographic and artifactual analyses. This thesis explores the atlatl at Chich(&)#233;n Itz(&)#225;, Tikal, and Caracol Maya sites to prove that atlatl prevalence can be interpreted primarily based on projectile point (")classification function(") analysis with support from iconographic and artifactual remains. The classification functions are derived from creating mutually exclusive groups of dart points and arrow points by using discrete functional analysis. Discerning between dart and arrow points can be completed with a high degree of accuracy based on maximum shoulder width of lithic points in an assemblage. Because the atlatl and bow complexes have been primarily constructed of perishable materials, the best method to determine the prevalence of atlatl use is by identifying the launcher based on projectile point identification. Using a cross-site comparison of projectile point size, the Maya use and prevalence of the atlatl will be elucidated.
Show less - Date Issued
- 2012
- Identifier
- CFE0004193, ucf:49034
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004193
