Quantification of selected synthetic cannabinoids and Δ9-tetrahydrocannabinol in oral fluid by liquid chromatography–tandem mass spectrometry

• We develop an LC–MS/MS method for synthetic cannabinoids quantification in oral fluid.
• The method was validated according to international guidelines.
• The method was applied to real samples collected from Spanish drivers.
• Results did not revealed consumption of these emerging drugs in our country.

An LC–MS/MS method for the quantification of the synthetic cannabinoids JWH-200, JWH-250, JWH-073, JWH-018, HU-211, CP 47,497 and CP 47,497-C8, and THC in oral fluid was developed and validated. Samples (0.5 mL) were extracted using Strata X cartridges (Phenomenex). Chromatographic separation was achieved with a Sunfire™ IS column (20 × 2.1 mm, 3.5 μm) (Waters Corp.), with formic acid 0.1% and acetonitrile as mobile phase. A different chromatographic gradient was applied for the separation of the analytes depending on the ionization mode employed, with a total chromatographic run of 14 min. Detection was performed in a Quattro Micro™ API ESCI (Waters Corp.), using electrospray in the positive mode (ESI+) for JWH-200, JWH-250, JWH-073, JWH-018 and THC, and ESI- for HU-211, CP 47,497, and CP 47,497-C8. Validation of the method included the assessment of selectivity, linearity (0.1–2.5 to 200 ng/mL), limits of detection (0.025–1 ng/mL) and quantification (0.1–2.5 ng/mL), imprecision (%CV ≤ 14.4%), accuracy (91.8–109.7% of target concentration), extraction recovery (65.4–105.6%) and Quantisal recovery (56.1–66.7%), and matrix effect (neat oral fluid: −56.0% to 38.5%; oral fluid in Quantisal buffer: −15.1% to −71.7%). The application of this method to oral fluid samples from roadside testing will provide unique information on the use of these new synthetic drugs by Spanish drivers.