Title
Isotopic and elemental profiling of ammonium nitrate in forensic explosives investigations
Author
Brust, H.
Koeberg, M.
van der Heijden, A.
Wiarda, W.
Mügler, I.
Schrader, M.
Vivo-Truyols, G.
Schoenmakers, P.
van Asten, A.
Publication year
2015
Abstract
Ammonium nitrate (AN) is frequently encountered in explosives in forensic casework. It is widely available as fertilizer and easy to implement in explosive devices, for example by mixing it with a fuel. Forensic profiling methods to determine whether material found on a crime scene and material retrieved from a suspect arise from the same source are becoming increasingly important. In this work, we have explored the possibility of using isotopic and elemental profiling to discriminate between different batches of AN. Variations within a production batch, between different batches from the same manufacturer, and between batches from different manufacturers were studied using a total of 103 samples from 19 different fertilizer manufacturers. Isotope-ratio mass spectrometry (IRMS) was used to analyze AN samples for their 15N and 18O isotopic composition. The trace-elemental composition of these samples was studied using inductively coupled plasma-mass spectrometry (ICP-MS). All samples were analyzed for the occurrence of 66 elements. 32 of these elements were useful for the differentiation of AN samples. These include magnesium (Mg), calcium (Ca), iron (Fe) and strontium (Sr). Samples with a similar elemental profile may be differentiated based on their isotopic composition. Linear discriminant analysis (LDA) was used to calculate likelihood ratios and demonstrated the power of combining elemental and isotopic profiling for discrimination between different sources of AN.
Subject
Fluid Mechanics Chemistry & Energetics
EM - Energetic Materials
TS - Technical Sciences
Defence, Safety and Security
(laser ablation-) inductively coupled plasma-mass spectrometry
Ammonium nitrate
Chemical profiling
Explosive
Isotope-ratio mass spectrometry
Likelihood ratios
Ammonium nitrate
Calcium
Fertilizer
Iron
Isotope
Magnesium
Nitrogen
Oxygen
Strontium
Analytic method
Chemical composition
Controlled study
Crime
Discriminant analysis
Isotope ratio mass spectrometry
Isotopic and elemental profiling
Mass spectrometry
To reference this document use:
http://resolver.tudelft.nl/uuid:2cebf89a-1bc2-423a-88c3-928ae11c5554
DOI
https://doi.org/10.1016/j.forsciint.2014.11.024
TNO identifier
522500
Publisher
Elsevier Ireland Ltd
ISSN
0379-0738
Source
Forensic Science International, 248, 101-112
Document type
article