Rapid screening and identification of novel psychoactive substances using PaperSpray interfaced to high resolution mass spectrometry.

The simple and rapid detection and identification of designer drugs is of substantial importance to forensic scientists and law enforcement. Although synthetic cathinones, cannabinoids, and other common novel psychoactive substances (NPS) are produced for purposes that do not include human consumption, they are regularly abused. The analysis of these compounds is often achieved using mass spectrometry, but can be complicated by the lack of spectral libraries and the scarcity of simple and reliable sample introduction techniques.

Unbound drug concentration in brain homogenate and cerebral spinal fluid at steady state as a surrogate for unbound concentration in brain interstitial fluid.

The objective of the present study was to examine the accuracy of using unbound brain concentration determined by a brain homogenate method (C(ub)), cerebral spinal fluid concentration (C(CSF)), and unbound plasma concentration (C(up)) as a surrogate for brain interstitial fluid concentration determined by brain microdialysis (C(m)). Nine compounds-carbamazepine, citalopram, ganciclovir, metoclopramide, N-desmethylclozapine, quinidine, risperidone, 9-hydroxyrisperidone, and thiopental-were selected, and each was administered as an intravenous bolus (up to 5 mg/kg) followed by a constant intravenous infusion (1-9 mg/kg/h) for 6 h in rats. For eight of the nine compounds, the C(ub)s were within 3-fold of their C(m); thiopental had a C(m) 4-fold of its C(ub).