Identifying electrochemical fingerprints of ketamine with voltammetry and LC-MS for its detection in seized samples

Herein, a straightforward electrochemical approach for the determination of ketamine in street samples and seizures is presented by employing screen-printed electrodes (SPE). Square wave voltammetry (SWV) is used to study the electrochemical behavior of the illicit drug, thus profiling the different oxidation states of the substance at different pHs. Besides, the oxidation pathway of ketamine on SPE is investigated for the first time with liquid chromatography-high resolution mass spectrometry. Under the optimized conditions, the calibration curve of ketamine at buffer solution (pH 12) exhibits a sensitivity of 8.2 µA µM-1, a linear relationship between 50-2500 µM with excellent reproducibility (RSD= 2.2%, at 500 µM, n=7), and a limit of detection (LOD) of 11.7 µM. Subsequently, binary mixtures of ketamine with adulterants and illicit drugs are analyzed with SWV to investigate the electrochemical fingerprint. Moreover, the profile overlapping between different substances is addressed by the introduction of an electrode pretreatment, and the integration of a tailor-made script for data treatment. Finally, the approach is tested on street samples from forensic seizures. Overall, this system allows for the on-site identification of ketamine by the law enforcement agents in an easy-to-use and rapid manner on cargos and seizures, thereby disrupting the distribution channel and avoiding the illicit drug to reach the end-user.

Jaar van publicatie:2020

Trefwoorden:A1 Journal article

BOF-keylabel:ja

BOF-publication weight:6

CSS-citation score:1

Auteurs:International

Toegankelijkheid:Open