Identification and characterization of the new designer drug 4'-methylethcathinone (4-MEC) and elaboration of a novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) screening method for seven different methcathinone analogs.

A fast and simple LC-MS/MS method was developed for screening mephedrone, butylone, methylenedioxypyrovalerone (MDPV), flephedrone, methylone and methedrone in bulk powder samples. Samples were separated on a reverse phase column using gradient elution with mixtures of water, acetonitrile and formic acid. After optimization a limit of detection of about 2ngmL(-1) was achieved using multiple reaction monitoring (MRM) mode. Total run time was less than 8min. Typical fragmentation characteristics of the studied compounds are discussed. The method was successfully applied to several unknown bulk powder samples seized by the Hungarian Customs and Finance Guard. One of the samples contained the new designer drug 4'-methylethcathinone (4-MEC), which was identified and characterized by LC-MS/MS, NMR, FT-IR and LC-TOF-MS techniques. The method is also deemed to be applicable for the screening of simple dosage forms such as tablets and capsules.