Screening of seized emerging drugs by ultra-high performance liquid chromatography with photodiode array ultraviolet and mass spectrometric detection.

The use of psychoactive "designer drugs" has increased rapidly due to their varying and sometimes ambiguous legal status and their ready access via the Internet and at local "headshops." A quick screening method for samples containing these substances, using ultra-high performance liquid chromatography with photodiode array UV and mass spectrometric detection (UHPLC-PDA/UV-MS), is presented. The method enables the screening of a variety of samples containing emerging/reemerging drugs, including β-keto phenethylamines (cathinone derivatives), synthetic cannabinoids/cannabimimetics, and phenethylamine derivatives. The use of dual detectors not only provides molecular weight information but also differentiates the drugs by their categories and in some cases even their sub-categories. Moreover, ring positional isomers of cathinone and phenethylamine derivatives can be easily differentiated by their retention times and UV spectra.