ASTM E2927-23 pdf free download – Standard Test Method For Determination Of Trace Elements In Soda-Lime Glass Samples Using Laser Ablation Inductively Coupled Plasma Mass Spectrometry For Forensic Comparisons.
One objective of a forensic glass examination is to compare glass samples to determine if they canbe discriminated by their physical, optical, or chemical properties (for example, color, refractive index(RI), density, elemental composition). If the samples are distinguishable in any of these observed andmeasured properties, it can be determined that they did not originate from the same source of brokenglass. If the samples are indistinguishable in all these observed and measured properties，thepossibility exists that they originated from the same source of glass. The use of an elemental analysismethod such as laser ablation inductively coupled plasma mass spectrometry yields high discrimina-tion among sources of glass.
This test method presents a procedure for the precise quantitative analysis of seventeen specific elements, including lithium (Li), magnesium (Mg), aluminum (Al), potassium (K), calcium (Ca), iron (Fe), titanium (Ti), manganese (Mn), rubidium (Rb), strontium (Sr), zirconium (Zr), barium (Ba), lanthanum (La), cerium (Ce), neodymium (Nd), hafnium (Hf), and lead (Pb). The analysis is conducted using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and is primarily employed in the forensic comparison of glass fragments. Previous studies have indicated that these elements offer optimal discrimination among various sources of soda-lime glasses (1-5). Silicon (Si) is also monitored as a normalization standard, and additional elements, such as tin (Sn), can be included to assess the orientation of float glass fragments.
1.2 This method requires a minimal amount of glass, approximately ranging from 0.4 µg to 3 µg per analysis, making it suitable for analyzing full thickness samples and irregularly shaped fragments as small as 0.1 mm by 0.1 mm by 0.2 mm (6) in size. The concentrations of the aforementioned elements in soda-lime glass, the most commonly encountered type in forensic cases, can vary from low parts per million (µgg-1) to percent (%) levels. While this standard method can be adapted for the quantitative analysis of other glass types, adjustments to the reference standard glasses and element selection may be necessary.
1.3 This standard is specifically designed for proficient forensic science practitioners who possess the necessary formal education, discipline-specific training (refer to Practice E2917), and demonstrated expertise to conduct forensic casework.
1.4 All values provided in this standard are in SI units and should be considered the standard. No other units of measurement are included in this standard.
