The Defence Science and Technology Laboratory (Dstl), which provides services for the Ministry of Defence, has been mentoring 2 forensic science students in explosive materials research.
The students, Holly Yu from the University of Strathclyde and Leo Salvia of King’s College London, have been working with Dstl’s forensic exploitation group as part of their Master of Science (MSc) research projects.
Working over a 3-month period, Holly investigated the degradation of trace (invisible) levels of trinitrotoluene (TNT) in various solvents as part of her MSc in forensic science under the supervision of Professor Niamh Nic Daeid at Strathclyde.
Trace residues often provide valuable forensic evidence in crimes involving the misuse of explosives. It is extremely important that forensic scientists understand, and are able to mitigate against, any sampling and storage issues that could adversely affect the ability to identify explosives traces prior to laboratory analysis.
Holly examined the degradation of TNT under common pre-analysis storage conditions and found that increased temperatures and exposure to UV light could increase degradation rates.
As a result, Holly recommended that ‘explosives trace samples should be transported to laboratories in cool conditions, shielded from UV light, before being immediately stored in a freezer until processing and analysis is possible’.
Leo’s investigation of mass spectrometry is part of a broader programme of activity to enhance the capabilities of Dstl’s forensic explosives laboratory (FEL).
High performance liquid chromatography-mass spectrometry is commonly used to analyse specific explosive materials, but currently FEL does not have a method that facilitates the analysis of a wider range of possible explosives analytes.
Leo’s study was performed with Dr Leon Barron at King’s College London and focused on the conditions required to identify 19 common organic explosives in a single chemical analysis.
Such an outcome would significantly strengthen FEL’s capability to screen forensic samples more efficiently for a wide range of explosives.
Commenting on his work, Leo said:
The outcomes facilitated the streamlining of detection methods currently used into 1 combined solution. Hopefully, this will add to the efficiency of explosives analysis at FEL.
Dstl’s Dr Matthew Beardah worked closely with both students on their projects and praised the quality and contributions of their research:
Holly’s work is of considerable benefit in enhancing our understanding of particular characteristics of TNT, especially as it relates to the storage of TNT in solution,” he said. “This in turn should lead to improved reproducibility of standards and thus improved accuracy of casework.
The ongoing work at King’s College London, of which Leo’s research is a major part, will directly feed into a step-change in capability at FEL by introducing high resolution mass spectrometry to casework. We now look forward to agreeing next steps in finalising this valued research.
The projects are part of ongoing research collaborations with the universities, and discussions are now taking place on the next steps to build on the high-quality work of the students.