An initial evaluation of stable isotopic characterisation of post-blast plastic debris from improvised explosive devices

An inter‐laboratory comparative study into sample preparation for both reproducible and repeatable forensic 2H isotope analysis of human hair by continuous flow isotope ratio mass spectrometry

“…Bulk stable isotope analysis of organic compounds and materials for their 2 H, 13 C, 15 N or 18 O isotopic composition using continuous flow isotope ratio mass spectrometry (CF‐IRMS) either on its own or in conjunction with otheranalytical techniques is an increasingly used tool in forensic chemical analysis of evidence types such as drugs, explosives, plastic, as well as human remains . While the avoidance of non‐quantitative, mass‐discriminatory processes that may result in mass‐dependent isotopic fractionation is a concern for stable isotope analysis of any light element, analysis of samples for their 2 H and 18 O isotopic composition poses a particular challenge.…”

“…The between-laboratory differences for obtained d 2 H hair,true values ranged from 0.1 to 2.5 %. With an overall 95% confidence interval of AE2.8 %, these differences were not significantly different, which suggests that the general method of two-stage exchange equilibration carried out at ambient temperature is suitable for accurately and reproducibly determining 'true' Bulk stable isotope analysis of organic compounds and materials for their 2 H, 13 C, 15 N or 18 O isotopic composition using continuous flow isotope ratio mass spectrometry (CF-IRMS) either on its own or in conjunction with otheranalytical techniques is an increasingly used tool in forensic chemical analysis of evidence types such as drugs, [1][2][3] explosives, [4,5] plastic, [6] as well as human remains. [7,8] While the avoidance of non-quantitative, mass-discriminatory processes that may result in mass-dependent isotopic fractionation is a concern for stable isotope analysis of any light element, analysis of samples for their 2 H and 18 O isotopic composition poses a particular challenge.…”

Polymers on the Crime Scene

“…It is therefore surprising that the application of IRMS measurements in trace evidence is very underrepresented [91]. Only a few reports exist in the literature on post blast debris [92,93], architectural paints [94], plastic bags [95], and adhesive tapes [6,96,97].…”

“…As an example, Quirk et al published a work in which they used IRMS to associate post-blast residues of two-way radios with the undamaged radio used to initiate explosive devices. They found that apparati with sequential serial numbers were not necessarily made from all of the same components [92].…”

Recent Advances in the Application of Stable Isotope Ratio Analysis in Forensic Chemistry

“…They illustrate this with a ternary plot showing the combination of three isotopes (C, N, and O) which clearly differentiates PETN, ANFO, TNT, and semtex, despite the semtex containing 80% PETN within its composition. The most recent paper by Quirk et al [23] looks at the possibility of using IRMS to link a pair of radios used to initiate an improvized explosive device where one radio is intact and the other partially destroyed by the blast.This clever idea is explained clearly in the paper and the conclusions are encouraging. Four pairs of radios were studied, and in each pair one was retained as a reference while the other was detonated.…”