Within this research theme we apply a carefully selected complementary, novel analytical techniques to deliver significant advances in the sensitivity of methods available for analysis of administered drugs and their metabolites. Our active collaborations with forensic practitioners ensure that our research is focused upon the development of efficient, relatively low cost methods and techniques, which are readily transferable to other forensic science laboratories. An additional focus of this research theme is study of the metabolic pathways of target drugs to identify and isolate compounds that may be present in the body for longer periods of time, allowing significantly improved detection windows. Some examples of our current and recently completed projects include:
Investigating the Incorporation and Distribution of Metabolites of Drugs in Hair for Forensic Toxicology
Collaborators: ROAR Forensics, National Physical Laboratory.
Funded through a King’s internally allocated BBSRC doctoral training grant, this project aims to improve understanding of drug metabolite distribution in human hair and, hence, enable better interpretation and application of this evidence type in forensic toxicology. It is known that distinct bands of incorporated drugs and metabolites from the bloodstream may be broadened as the mature hair shaft is daily ‘bathed’ in sweat, which also contains drugs and their metabolites. This project will examine the ability of highly-sensitive analytical techniques, in combination with specific drug metabolites, to enable improved discrimination between active ingestion of a drug and environmental contamination of the hair shaft. We aim to transfer the techniques developed within this project to our supporting commercial partner, for incorporation into their forensic analysis services. This will extend the UK capability in the field of forensic hair analysis for determination of drug administration, to rival that of centers of excellence in France, Germany and the USA.
Development of Novel High Sensitivity and Specific Methods to Provide Reliable Forensic Evidence of Drug Administration in Vulnerable Groups
Collaborators: The Forensic Science Service, the Regional Toxicology Laboratory – Birmingham City Hospital.
In this EPSRC “Think Crime” funded project new, ultra-sensitive analytical techniques were developed to aid detection of drug facilitated sexual assaults (so-called 'date rape') and non-accidental poisoning of children. In these two important and growing types of serious crime, forensic analysis is particularly challenging due to the often late collection of evidence and concomitant low levels of drug present, and the availability of only very small samples. With use of existing methods of analysis these difficulties may cause crucial forensic evidence to be missed.
This project has largely addressed the critical capability gap in forensic science for investigation of these crimes, through development of new ultra-sensitive micro LC-MS/MS techniques capable of detecting drugs and their breakdown products in the body at extremely low amounts (less than 1 part in 10 billion - 100 pg/mL) in small samples of urine. In addition, the development of a novel in-vitro method for generation of drug metabolites, though use of human liver preparations, enabled the identification of novel, long-lived metabolites of drugs including ketamine and lorazepam. In this project the identification of the drug metabolites resident longer in the body, combined with ultra-sensitive methods of analysis, enables the detection of drug administration over a significantly increased time window. These valuable new methods have been disseminated to the toxicology communities, both in the UK and internationally, through conference presentations and publications.
Forensic toxicology research at King’s benefits from its active collaborations with both the Drug Control Centre and clinical partners within King’s Health Partners.
Current collaborative work includes:
- Identification of a marker of illicit heroin administration that gives better retrospection of detection than 6-monoacetylmorphine to address the poppy seed defence.
- Demonstrating that quinazilinone and particularly the quinazoline carboxylic acid provided longer detection windows than lorazepam in urine extracts not subjected to enzymatic hydrolysis.