Sampling Strategies For The Analysis Of Glass Fragments By La-Icp-Ms Part 1. Micro-Homogeneity Study Of Glass And Its Application To The Interpretation Of Forensic Evidence

This paper evaluates the micro-homogeneity of the elemental composition of glass samples commonly found in crime scenes like containers, architectural windows and windshields. The set of glasses under study was comprised of 56 fragments of which 8 originated from glass containers, 28 fragments from automobile windshields and 20 fragments from architectural windowpanes. All fragments were smaller than 2mm2 in order to simulate the typical glass fragments transferred from the crime scenarios. A Nd:YAG laser, 266nm, flat top beam profile was used in single point mode sampling 50um spot size for 50 at 10Hz (500 shots) In this study, Si was used as an internal standard and the standard reference material, SRM NIST 612, was used as a single point external calibrator. In addition, SRM 621 was used as another control standard for the containers and SRM 1831 for the automotive sets.