Utilization of micellar electrokinetic chromatography–tandem mass spectrometry employed volatile micellar phase in the analysis of cathinone designer drugs

A micellar electrokinetic chromatography method with tandem mass spectrometry has been developed for the selective separation, identification and determination of twelve new designer drugs from the group of synthetic cathinones. Ammonium salt of perfluorooctanoic acid at various concentrations as a volatile background electrolyte (BGE) to create micellar phase was studied for separation of selected synthetic cathinones with direct tandem mass spectrometry without significant loss of detection sensitivity. The optimized BGE contained 100 mM perfluorooctanoic acid with 200 mM ammonium hydroxide providing acceptable resolution of studied drugs in the MEKC step. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid phase extraction was introduced as a clean-up step. The method was linear in the concentration range of 10–5000 ng mL−1 and the limits of detection were in the range of 10–78 ng mL−1. The method was demonstrated to be specific, sensitive, and reliable for the systematic toxicological analysis of these derivatives in urine samples.