Simultaneous enantioseparation of methcathinone and two isomeric methylmethcathinones using capillary electrophoresis assisted by 2-hydroxyethyl-β-cyclodextrin.

Methcathinone (ephedrone), 4-methylmethcathinone (mephedrone), and 3-methylmethcathinone (metaphedrone) are toxicologically-important cathinone derivatives used commonly as designer drugs. In this work we show the first method allowing to separate simultaneously all these molecules in a chiral medium, ensuring good resolution between all enantiomers. Eight cyclodextrins have been tested as potential chiral selectors, the best results were obtained with 2-hydroxyethyl-β-cyclodextrin, unreported so far for efficient separation of cathinones. After optimization, the method was calibrated and validated with and without the use of internal standard. The addition of standard improved an overall repeatability and precision, the use of electrophoretic mobility ratio was especially favorable (RSD < 1%). It was demonstrated that the method may be easily extended by introducing the additional cathinone-related drugs to the sample, maintaining satisfactory separation efficiency.