Isotonitazene, a benzimidazole, is one of the most recent designer opioids to emerge on the illicit drug scene in the United States and the rest of the world. Its recent activity has led the Drug Enforcement Agency to declare isotonitazene as an emergency threat, and it has been temporarily classified as a Schedule I drug. The prevalence of isotonitazene activity has been high in midwest cities such as Chicago and Indiana. In collaboration with the St. Louis University Forensic Toxicology Laboratory, isotonitazene was added to the general screening process for all casework as of August 3, 2020. This screening process is an information dependent acquisition (IDA) method on a Sciex X500R QqTOF System equipped with a chromatography system. This system is able to separate drugs and their metabolites and detect them if they are above a limit of detection. The limit of detection of isotonitazene was determined to be 0.12 ng/mL through the use of serial dilutions with blank blood. There was a re-analysis of casework submitted from August 2019 to July 2020 to determine whether any cases missed isotonitazene prior to the development of this screen. There were 64 samples chosen to go through the Sciex X500R QqTOF System based on the substances that isotonitazene is usually mixed with: fentanyl, amphetamines, tramadol, and cocaine. Out of the 64 samples screened, none of them were able to confirm that isotonitazene was present. However, the threat is still present as its prevalence in the United States has increased.

Hunter Chamma would like to thank Erik Hall, the faculty sponsor, for his support of this project. Additionally, Hunter would like to thank Dr. Sarah B. Riley and her team for the opportunity to intern and do research in the toxicology lab.