Elemental Analysis of Glass by SEM-EDS, XRF, EPMA, LIBS and LA-ICPMS

The proposed research will expand on the PIs research in the area of elemental analysis of materials (DoD/TSWG, end date 12/2002 and NIJ, end date 7/2005) to conduct a thorough evaluation of a number of elemental analysis methods and compare the discrimination power between the methods used in most forensic laboratories. Glass is proposed as a model system due to the availability of matrix-matched standards and the forensic interest of the material as transfer evidence. The proposed work aims to evaluate the informing power of scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), X-Ray fluorescence spectrometry (XRF), and LA-IPCMS and compare these methods to the emerging technique of laser induced breakdown spectrometry (LIBS) for the comparison of glass samples. A carefully selected set of ~ 500 glass samples will be analyzed by the above methods to determine the informing power of each of the techniques to differentiate between glass samples. In addition, two commercially available LIBS instruments will be used to evaluate the utility of the LIBS instruments and to provide feedback to the manufacturers so that the instruments can be improved and optimized for forensic applications.

ca/ncf