Novel approaches for illicit-drug identification in forensic investigations

The forensic illicit-drug analysis field is facing challenges in both an increasing number of seized substances and an increasing complexity of the encountered drugs due to the emergence of 1000+ new designer drugs (new psychoactive substances, NPS) in the last decade. Consequently, forensic laboratories are confronted with both an increasing workload and limitations of the current analytical methodology in terms of selectivity and efficiency. This thesis presents novel approaches for illicit-drug identification focused around two main themes: the NPS challenge, and on-scene drug analysis with portable technology. The NPS analysis part presents seven chapters describing new methodologies to differentiate and identify designer drug analogues with techniques such as GC-VUV, GC-FTIR, infrared ion spectroscopy, and chemometric analysis of GC-MS data. The portable technology part presents nine chapters on the applicability, concepts, and evidential value of mobile detection of drug-suspected items directly at the crime scene. Near-Infrared (NIR) spectroscopy, Raman spectroscopy, and electrochemical detection-based methods were developed and tested on casework samples seized by the Netherlands Police. For NIR spectroscopy, various sensors operating in different wavelength ranges were compared and evaluated for its applicability in the forensic field. Overall, this thesis provides new methods and approaches that contribute to a more robust, reliable, and efficient illicit-drug identification in the forensic investigation process.