Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [137]-146).

Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2010. / Committee Chair: Fernández, Facundo; Committee Member: Bottomley, Lawrence; Committee Member: Mizaikoff, Boris; Committee Member: Orlando, Thomas; Committee Member: Prausnitz, Mark. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M. Sc.)(Chemistry)--University of Pretoria, 2005. / Includes summaries in English and Afrikaans. Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (Ph.D.)--Ohio University, November, 2004. / Includes bibliographical references (p. 186-195 )

Thesis (Ph.D.)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (p. 186-195 )

Thesis (Ph.D.)--Ohio University, November, 2004. / Includes bibliographical references (p. 163-171)

Thesis (Ph.D.)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (p. 163-171)

The goal of this project was to reduce processing time for forensic DNA testing without incurring significant added costs and/or the need for new instrumentation, while still generating high quality profiles. This was accomplished by: 1) extraction normalization using the ChargeSwitch® Forensic DNA Purification Kit such that a small range of DNA concentrations was consistently obtained, eliminating the need for sample quantification and dilution; 2) developing fast PCR protocols for STR primer sets using shorter amplification methods, low volume reactions and non-fast thermal cyclers; and 3) developing a quicker 3130xl Genetic Analyzer detection method using an alternative polymer/array length combination. Extraction normalization was achieved through a reduction in bead quantity, thereby forcing an increase in bead binding efficiency. Four products (AmpliTaq Gold® Fast PCR Master Mix, KAPA2G™ Fast Multiplex PCR Kit, SpeedSTAR™ HS DNA Polymerase and Type-it Microsatellite PCR Kit) were evaluated for low volume (3μl) fast PCR on a 384-well Veriti® thermal cycler with the Identifiler primer set. KAPA2G™ was selected for 3μl fast PCR protocols using PowerPlex 16 HS and Identifiler Plus primer sets (42-51min), as well as 5μl and 6μl Identifiler fast reactions on a 9700 thermal cycler (51-60min). Alternative detection (POP-6™/22cm) achieved 24-28min run times, but with decreased resolution as compared to traditional POP-4®/36cm detection for alleles >200bp; however, 1bp resolution was still obtainable for alleles <300bp. These modifications resulted in robust databasing processes with up to a 37% reduction in processing time for buccal swabs and Buccal DNA Collectors™ using the three primer sets evaluated (3μl fast PCR reactions) and generated high quality STR profiles with ≥90% pass rates.

Ambient mass spectrometry (MS) is a new and growing sub-field in MS which has opened new research avenues, particularly for applications relating to the analysis of solid samples. Results on the implementation and application of ambient MS techniques including: desorption electrospray ionization (DESI) and direct analysis in real time (DART) indicated that these techniques could serve as complementary tools for the rapid qualitative screening of pharmaceuticals, allowing up to two orders of magnitude improvement in throughput compared to traditional methods such as liquid chromatography MS. The selectivity of DESI could be enhanced by performing the experiment in the reactive mode. In this mode, complexation reactions between reagents added to the spray solvent and analytes on the sample surface resulted in analyte stabilization, inhibiting fragmentation. They also resulted in a concomitant enhancement in the analyte surface activity, facilitating their evaporation from secondary droplets culminating in an improvement in sensitivity. Also for drug tablets analysis, the analyte signal dependency on DESI geometrical set-up variables could be mitigated following the careful and controlled addition of an isotopically labeled internal standard (IS) to the sample or by spraying samples with a pair of reagents with different affinities for the analyte. Either of these approaches resulted in an analyte-to-IS signal ratio (in the former) or an analyte complex ratio (in the later), which was largely independent of DESI experimental variables allowing quantitative analysis using this technique. DESI MS was also observed to be a very powerful tool for determining the 2-D distribution of various pharmaceutically important compounds on tablet and tissue surfaces. The ability to map the distribution of molecules of interest by DESI MS has very great implications in drug tablet quality control and in determining the role of chemical signals presented on tissue surfaces. DESI was observed to be limited to ionizing molecules of medium to high polarities without much limitation in terms of mass range, whereas DART was better suited for the analysis of molecules within a broader range of polarities, but within a more limited mass range (up to 800 Da approximately). These limitations were circumvented by implementing a novel multimode ambient ion source, desorption electrospray/metastable-induced ionization (DEMI), which combines various aspects of DESI and DART. Initial experiments with the DEMI ion source demonstrated its ability to enable the simultaneous analysis of molecules within a broader range of polarities and masses than DESI and DART alone.

[Truncated abstract] The analysis and subsequent interpretation of trace evidence is of paramount importance to the forensic scientist. While a variety of methods are available to facilitate comparison between recovered and control samples, the use of a specific analytical method depends upon both the physical and chemical nature of the material itself and the material to which it is to be compared. Elemental analysis of evidentiary material is one such method of sample comparison and has been extensively applied to this purpose following the introduction of neutron activation analysis in the early 1960s. However, over the last 15 years, another instrumental technique has taken centre stage in the analytical armoury of the forensic scientist: laser ablation–inductively coupled plasma-mass spectrometry (LA-ICP-MS). The modification and adaptation of this technique, to a point where it is possible to distinguish between glass materials produced only hours apart on the same production line, is detailed in this thesis. Additional protocols have also been developed for the analysis of fibreglass and plastic crime scene debris. Finally, a method for quantification of elemental concentrations in headlamp plastics has also been developed to facilitate inter-comparison of data between both different analytical techniques and different laboratories. Glass material is one of the most common varieties of trace evidence and the forensic examination of glass traditionally involves the determination of its refractive index (RI). ... The analytical protocol involves the analysis of 46 analytes on material comprising the exterior surface of the lens. Using this data, it was found that although minor variations in elemental composition exist within a single headlamp lens, discrimination between lenses produced from a single manufacturing plant over a short period of time could still be achieved. Discrimination between all headlamp lenses, with the exception of some lenses produced on the same day, could be facilitated using the analytical protocol developed. Furthermore, an interpretational protocol has been developed that has successfully classified all unknown headlamp lens samples investigated in this study, within the discrimination limits of the analytical method. The semi-quantitative analysis of glass and plastic samples has also been examined using LA-ICP-MS. The concentrations of 16 analytes in container and float glass samples were determined. However, the levels of discrimination afforded by the semi-quantitative data were inferior to those achieved using qualitative data. Finally, a series of plastic-based standards, containing 25 analytes of known concentrations, was produced. Using these standards, relative concentrations of the study analytes were determined in polycarbonate headlamp lenses. Interpretation of the data produced made it possible to discriminate between all study samples. Consequently, the total analytical and interpretational protocol developed in this study has established the foundation for LA-ICP-MS to be adopted internationally as a recognised method for the analysis of plastic crime scene debris.