Multicomponent characterization and differentiation of flash bangers - Part II: Elemental profiling of plastic caps

Area of Science:

• Forensic Science
• Analytical Chemistry
• Materials Science

Background:

• Flash bangers require robust forensic analysis strategies.
• Previous multicomponent analysis focused on pyrotechnic charges.
• Plastic components offer an alternative avenue for forensic differentiation.

Purpose of the Study:

• To expand forensic strategies for flash banger analysis.
• To investigate elemental and isotopic composition of plastic caps for differentiation.
• To develop methods applicable to both intact and post-explosive samples.

Main Methods:

• Elemental analysis using X-ray fluorescence (XRF) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS).
• Isotopic analysis using isotope ratio mass spectrometry (IRMS) for carbon and hydrogen.
• Combined visual examination with elemental and isotopic data.

Main Results:

• XRF is suitable for semi-quantitative analysis of intact plastic caps, with reduced inhomogeneity effects.
• LA-ICP-MS is useful for characterizing post-explosive residues but limited by inhomogeneity and lack of reference materials.
• Blue caps showed higher elemental content than white caps due to colorant additives.
• IRMS analysis of carbon and hydrogen isotopes successfully differentiated samples with similar visual and elemental characteristics.

Conclusions:

• Elemental and isotopic analysis of plastic caps provide a unique, charge-independent method for flash banger characterization.
• XRF is preferred for intact caps, while LA-ICP-MS is valuable for post-explosive analysis.
• IRMS significantly enhances differentiation potential, especially for visually and elementally similar samples.