Development and validation of a simple chromatographic method to screen oral fluid samples for drugs in DUID investigations.

The article focuses on the development and validation of a rapid, qualitative liquid chromatography–tandem mass spectrometry (LC–MS-MS) screening method using a single-step liquid–liquid extraction (LLE) to detect 31 drugs and metabolites, including Tier I compounds and phencyclidine, in oral fluid samples for driving under the influence of drugs (DUID) investigations. The method meets or exceeds the National Safety Council's Alcohol, Drugs and Impairment Division Tier I recommendations and adheres to ANSI/ASB forensic toxicology standards. It utilizes the Quantisal™ oral fluid collection device, a unique solvent mixture (methyl tert-butyl ether, isopropanol, and hexane) for extraction, and a Restek Raptor™ biphenyl LC column, achieving an 8-minute run time with minimal sample volume (400 µl). Validation demonstrated adequate sensitivity, specificity, minimal carryover, and stability, with comprehensive interference testing addressing potential false positives and negatives, while confirmation methods provide further specificity. This approach offers a practical, efficient alternative to immunoassays and supports forensic toxicology laboratories in DUID casework with reduced sample consumption and improved analytical differentiation.