Elemental Analysis of Glass Fragments by ICP-MS as Evidence of Association: Analysis of a Case

Abstract

Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze glass evidence from a case in which a person broke a window in each of 15 vehicles in a parking lot in order to gain entry into the vehicles. The results of the analysis by traditional methods, which measure the properties of color, thickness, density, and refractive index, are also reported. A total of 15 known samples representing the windows on the cars and 42 questioned glass fragments recovered from the suspect and the police vehicle where the suspect was sitting were submitted for analysis. Density comparisons separated one of the known samples into three samples, increasing the number of known samples from 15 to 17. The concentrations of 16 elements were measured for all but three of the samples using an external calibration ICP-MS method with internal standardization. Color assessment (non-instrumental) separated the 17 known samples into two groups, and refractive index measurements resulted in six groups when the Emmons double variation method was used and ten groups when the Glass Refractive Index Measurement 2 (GRIM2) system was used. Elemental analysis, by itself, differentiated all of the known samples from each other and associated four of the known sample fragments with several of the questioned sample fragments. The informing power of RI, density, and elemental analysis comparisons is evaluated and a summary of the case results is reported.

Bioagent Sample Matching using Elemental Composition Data: an Approach to Validation

“…First, it uses well-understood techniques that are familiar in other forensic contexts. For example, bulk elemental analyses by Inductively Coupled Plasma -Mass Spectrometry (ICP-MS) or Inductively Coupled PlasmaOptical Emission Spectroscopy (ICP-OES) have been used to characterize glass 16 , office document paper 17 , and foils 18 . In addition, there are well-developed techniques for nondestructive elemental analysis of bulk samples such as X-ray Fluorescence (XRF), or that are applicable to trace samples such as Particle Induced X-ray Emission (PIXE) and Secondary Ion Mass Spectrometry (SIMS).…”

Forensic Discrimination of Sheet Glass by a Refractive-Index Measurement and Elemental Analysis with Synchrotron Radiation X-ray Fluorescence Spectrometry

“…11 In order to increase the evidential value of glass fragments by enhancing the discrimination capability, the analysis and comparison of elemental compositions have been investigated for the further discrimination of glass fragments using instrumental analysis, such as neutron activation analysis, 12 scanning electron microscopy/energy dispersive X-ray fluorescence, 13 X-ray fluorescence spectrometry (XRF), [14][15][16] atomic absorption spectrometry, 15 inductively coupled plasma atomic emission, 14,17,18 and inductively coupled plasma mass spectrometry (ICP-MS). [19][20][21][22][23] Among these procedures, ICP-MS is considered to be the most suitable for forensic glass examination, because it can offer high sensitivity indispensable for the analysis of trace impurities, the comparison of which is effective for the discrimination of various types of evidential materials. However, the application of ICP-MS to evidential glass is limited by its disadvantages, such as large amount of sample (2 -10 mg) required, destruction of fragments, complex and time-consuming pretreatment to dissolve glass into acid solution.…”

Distinguishing Between Legally and Illegally Produced Gold in South Africa

“…Anything from the ore to the final metal product is stolen and the challenge is to develop techniques like elemental profiling to identify the original source of the gold, despite different beneficiation procedures applied by companies and criminal syndicates. The mineralogy of gold ores from the Witwatersrand mines is relatively consistent and the recovery of the gold is easily achieved with unsophisticated methods, such as panning, amalgamation, and cyanidation [3,4].The trace element profiles of substances such as paint [5,6], glass [7,8] and precious metals [9] have been used to prove a link between a sample of the material in question and samples from known provenance. There have been problems with the interpretation of the results of such profiling [10], and this has been extensively discussed and reviewed in the literature [11].…”