Development and validation of a forensic workflow for the complete profiling of illicit drugs and excipients

• Validated forensic workflow developed for excipient and illicit drug screening. • Non-targeted analysis methods and HRMS for organic component characterisation. • Presumptive test false positive colour changes in the presence of excipients. • Workflow validated for application to counterfeit benzodiazepine preparations. • Forensic workflow using a combination of novel and common analytical techniques. The development of a complete understanding of the societal harms of illicit drug mixtures requires a greater emphasis on the complete identification of illicit and excipient compounds. To increase the feasibility of this in practice, common and emerging analytical techniques were examined in the context of developing a non-targeted forensic workflow. The purpose of this workflow was to increase the identification of excipient compounds without compromising the quality of illicit drug identification as required for admissibility of evidence in court. This incorporated the testing of simulated compound mixtures to develop the principal avenues of analysis. These pathways were then validated through the testing of unknown compound mixtures. The techniques of focus included GCMS, FTIR, LC-HRMS for identification, and LC-HRMS for quantitation. These techniques were organised into their respective categories of techniques, according to the SWGDRUG guidelines, to produce a workflow that would ensure the admissibility of evidence no matter the pathway taken. HRMS was examined as an emerging technique not currently used in illicit drug analysis facilitating non-targeted analysis pathways. From this, and in combination with GCMS, all organic components were identifiable in simulated and unknown mixtures. Partial identification was also achieved for insoluble compounds using FTIR analysis. Identification by HRMS was facilitated by comparison to reference standards and MS/MS spectra matching to the high-resolution database MzCloud. This demonstrated the applicability of HRMS, specifically the Exploris 120 Orbitrap, to the identification and quantitation of both illicit and organic excipient compounds within Forensic Chemistry.