Adding the Clues to CanKet's Presence in Toxicological Casework

A driving under the influence of drugs (DUID) case brought on the identification of a newly emerging ketamine analogue. Following a 12-step evaluation, a drug recognition expert collected a urine sample and a nasal swab from an individual who admitted to ketamine consumption. Systematic targeted screening was performed on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). This method covers 144 analytes, including 57 novel psychoactive substances (NPS). Further general unknown screening was performed using a gas chromatography – mass spectrometry (GC-MS) method. While both urine and the nasal swab were negative for ketamine in the LC-MS/MS analysis, an interference was noted in the 7-aminonitrazepam (urine) and eutylone (urine and nasal swab) windows (erroneous ion ratio). Both items’ GC-MS analysis turned out positive for 3- fluoro-2-oxo PCE (fluorexetamine) when compared to the Cayman library. Discussion with the Canadian drug chemistry laboratory brought to light recent seizures of 2-fluoro-2-oxo PCE (CanKet). Injection of reference materials showed that these were undistinguishable under our current analytical methods. This case demonstrates that forensic toxicologists must remain alert to the appearance of previously undetected NPS in casework, the possibility of false identifications when relying on libraries, and subtle clues appearing in casework, such as interferences in other methods. Using the LC-MS/MS interferences as a CanKet proxy, 7 cases of DUID were subsequently sent to GC-MS analysis and confirmed to contain 2-fluoro-2-oxo PCE.