Cannabinoids determination in oral fluid by SPME-GC/MS and UHPLC-MS/MS and its application on suspected drivers

摘要

The confirmation of Delta 9-tetrahydrocannabinol (THC) in oral fluid (OF) is an important issue for assessing Driving Under the Influence of Drugs (DUID). The aim of this research was to develop a highly sensitive method with minimal sample pre-treatment suitable for the analysis of small OF volumes (100 mu L) for the confirmation of cannabinoids in DUID cases. Two methods were compared for the confirmation of THC in residual OF samples, obtained from a preliminary on-site screening with commercial devices. An ultra high performance LC-MS (UHPLC-MS/MS) method and an SPME-GC/MS method were hence developed. 100 pi, of the residual mixture OF/preservative buffer or neat OF was simply added to 10 mu L of THC-D3 (1 mu g/mL) and submitted to the two different analyses: A - direct injection of 10 mu L in UHPLC-MS/MS in positive electrospray ionisation (ESI) mode and B - sampling for 30 min with SPME (100 pm polydimethylsiloxane or PDMS fibre) and direct injection by desorption of the fibre in the GC injection port.