As the challenges faced by drug chemists continue to persist due to the presence of synthetic opioids, novel psychoactive substances, and other emerging drugs, laboratories are continuing to look for new analytical approaches or techniques to ease the burdens. These new solutions can range from simple changes in existing methods to better distinguish isomers to adoption and implementation of entirely new technologies for screening or confirmation. One barrier to making these transitions is lack of data to understand how, or even if, workflow changes will address the challenges. In this study, we attempt to compare, qualitatively and quantitatively, an existing analytical workflow for seized drug analysis to a new, experimental workflow to better understand the potential benefits and drawbacks. Using adjudicated and mock case samples containing synthetic cannabinoids, synthetic cathinones, and opioids, four forensic chemists were asked to analyze fifty samples using one of two workflows. The first was an existing workflow that employed color tests for screening alongside general purpose gas chromatography flame ionization detection (GC-FID) and general purpose gas chromatography mass spectrometry (GC-MS) analyses for confirmation. The second was an experimental workflow that combined direct analysis in real time mass spectrometry (DART-MS) for screening with class-specific (targeted) GC-MS methods for confirmation. At each step in the analysis scheme, chemists recorded the time required and as well as their interpretation of the results. Comparison of the workflows showed that screening by DART-MS required the same amount of time as color tests but yielded significantly more accurate, and specific, information. Confirmation using the general purpose GC-FID and GC-MS methods of the existing workflow required more than twice the amount of instrument time and data interpretation time while also presenting other analytical challenges that prevented compound confirmation in select samples. Use of targeted GC-MS methods simplified data interpretation, reduced consumption of reference materials, and addressed almost all the limitations of general purpose methods. While the experimental workflow is not yet validated for casework, this study shows how rethinking analytical workflows for seized drug analysis could greatly assist laboratories in reducing turnaround times, backlogs, and standards consumption. It also demonstrates the potential impact of being able to investigate workflow changes prior to implementation.
Comparing Two Seized Drug Workflows for the Analysis of Synthetic Cannabinoids, Cathinones, and Opioids
25 August 2021, Version 1
This content is a preprint and has not undergone peer review at the time of posting.