A Validated Method for the Detection of 32 Bath Salts in Oral Fluid

Workplace drug testing in Australia is usually adherent to one of two standards, AS/NZS 4308:2008 for urine or AS 4760:2006 for oral fluid. These standards prescribe the drugs tested, devices used and testing methodology followed by the testing agency. However, they are not comprehensive and for many years workers have been able to consume novel psychoactive substances to avoid detection and without consequences. Here, we present a validated method for the detection of 32 Synthetic Stimulant and Hallucogenic drugs, commonly sold as bath salts, in oral fluid. These drugs are cathinone, ephedrone, methylone, flephedrone, MDA, PMA, methedrone, TMA, MDMA, butylone, mephedrone, MDEA, MEC, pentedrone, MBDB, MTA, Alpha-PVP, MPBP, 2C-B, MDPV, DOB, 2C-T-2, TFMPP, DOET, 2C-T-7, naphyrone, MDAI, FMA, DMA, 25C-NBOMe, 25B-NBOMe and 25T4-NBOMe. Sample preparation was undertaken using a simple protein precipitation in acetonitrile. Chromatographic separation was achieved in 7.5 min on a Kinetex F5 column (50 mm × 3 mm × 2.6 μm) using 0.1% formic acid in water and acetonitrile as the mobile phases. The method was validated with limit of detection (1 ng/mL), limit of quantitation (2.5 ng/mL), selectivity, linearity (2.5-500 ng/mL), accuracy (85.3-108.4% of the target concentration) and precision (1.9-14%). This method was applied to 12 samples previously submitted for routine testing and two were found to contain 2-CB and DOB (5 and 4 ng/mL) and, MPBP and TFMPP (both at 4 ng/mL). This method provides for the rapid detection of a large number of compounds in oral fluid which is readily applicable to routine testing laboratories.