Analysis of drugs including illicit and new psychoactive substances in oral fluids by gas chromatography-drift tube ion mobility spectrometry

In this study, a gas chromatograph (GC) has been coupled to a drift tube ion mobility spectrometer (IMS) in order to develop an analytical procedure for the determination of psychoactive substances in oral fluids. Working parameters, including the GC-IMS interface ones, were adjusted in order to obtain sensitive and robust signals. A volume of 500 mu L of oral fluid was extracted with 250 mu L chloroform and, after centrifugation, were injected into the GC-IMS system. Amphetamine, methylone, alpha-PVP, ketamine, lidocaine, MPHP, cocaine, THJ-2201, and 5FADB were employed as model compounds, providing limits of detection from 6 to 15 mu g L-1 and recoveries from 70 to 115% for field oral fluids spiked with target analytes at 250, 500, and 600 mu g L-1. Moreover, two oral fluid certified reference materials were analysed by the proposed GC-IMS based methodology with obtained relative percentage errors lower than 8.4%, being the proposed GC-IMS procedure a reliable, selective, and sensitive technique for the determination of psychoactive substances in oral fluids.