In a study published in the Royal Society of Chemistry’s Analyst journal, a research team from the University of Surrey, in partnership with the National Centre of Excellence in Mass Spectrometry Imaging at the National Physical Laboratory (NPL) and Ionoptika Ltd, explains how they were able to distinguish between the fingerprints of those who handled cocaine with those who have taken the medicine—even if their hands have not been cleansed.
Image Credit: University of Surrey.
The brilliant science underlying the breakthrough is the use of mass spectrometry imaging technologies to find cocaine and its metabolites in fingerprints.
This is an advancement above earlier studies undertaken by the university. Surrey researchers were able to distinguish the difference between ingestion and touch if someone has cleansed their hands before providing a sample in 2020.
Given that a perpetrator at a crime scene is unlikely to wash their hands before leaving fingerprints, these new discoveries provide a considerable benefit to crime forensics.
The Surrey team has been using their world-leading experimental fingerprint drug detection method based on high-resolution mass spectrometry.
Using these methods, cocaine and its major metabolite, benzoylecgonine, may be imaged in fingerprints formed after ingesting or contact with cocaine.
It is viable to detect the difference between a person who has taken a drug and someone who has simply touched it by examining the pictures of cocaine and its metabolite in a fingerprint and studying the link between these molecules and the fingerprint ridges.
Over the decades, fingerprinting technology has provided forensics with a great deal of information about gender and medication. Now, these new findings will inform forensics further when it comes to determining the use of class A drugs. In forensic science being able to understand more about the circumstances under which a fingerprint was deposited at a crime scene is important.”
Dr Melanie Bailey, Reader, Forensic and Analytical Science and EPSRC Fellow, University of Surrey
“This gives us the opportunity to reconstruct more detailed information from crime scenes in the future. The new research demonstrates that this is possible for the first time using high-resolution mass spectrometry techniques,” added Bailey.
To image these metabolites excreted through the skin requires very powerful analytical tools such as the unique Water Cluster Source that Ionoptika has been developing for over a decade. It’s clear that this new technique will be important for forensic science in the future, and as a small business in the UK it’s very exciting to see the role that our J105 SIMS instrument has played in its development.”
Dr Allen Bellew, Applications & Marketing Manager, Ionoptika
“This novel application of three different techniques illustrates the capabilities of mass spectrometry imaging to enable next-generation forensics analyses. It is great to see that the work we do here at NPL and the facilities we have available to us at the National Centre of Excellence in Mass Spectrometry Imaging helped support this research,” concluded Dr Chelsea Nikula, Higher Research Scientist, NPL.
Costa, C., et al. (2021) Imaging mass spectrometry: a new way to distinguish dermal contact from administration of cocaine, using a single fingerprint. Analyst. doi.org/10.1039/D1AN00232E.