| Advances in analytical methodology involving novel sampling techniques followed by gas chromatographic separation and mass spectrometric detection are presented. Debris from simulated arson experiments was analyzed by solid-phase microextraction (SPME) was and systematically compared to results from the American Society for Testing and Materials activated charcoal strip (ACS) sampling method. SPME was shown to be as sensitive and selective as the ACS sampling, with a dramatic decrease in sampling time. A weathering study was also performed to assess the changing chromatographic pattern with evaporation of several petroleum products. Principal component regression (PCR) was applied to predict percentage of weathering. SPME was also coupled with fast gas chromatography, allowing a large improvement in the amount of analysis time and total samples turnaround time.; Electrical tape was studied using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to identify organic plasticizers in the tape backing. Multivariate statistics were applied to determine if this plasticizer was an appropriate analyte on which to base discrimination between tape brands. It was determined that two plasticizer families were used most often, phthalates and adipates, and further, due to the lack of variation, this analyte was not the most useful for discrimination. Natural fibers were characterized using py-GC/MS to aid in the identification of fiber type and origin. Pyrolysis products from cellulose, lignin, and other components were identified. Multivariate data analysis validated the ability to discriminate between fibers. An additional Py-GC/MS study characterized synthetic poly (p-phenylenethylene)'s substituted with a variety of different polymer side chains. Pyrolysis products characteristic of both the main and side chains were identified. Principal component analysis confirmed that polymers substituted with different side chains could be distinguished from one another.; Supercritical fluid extraction followed by GC/MS was used to detect the presence of cocaine, the cocaine metabolite benzoylecognine, morphine, and codeine in a National Institute of Standards and Technology hair standard and in several samples from forensic case studies. When compared to the conventional acid hydrolysis method for hair analysis, SFE was faster and gave higher recoveries. Quantities of illicit drugs detected in the hair were within reasonable or previously reported values. |
