Enantiomeric separation of tocainide and its analogues on an optically active crown ether-based stationary phase by liquid chromatography

Tocainide and its 14 analogues were resolved on a chiral stationary phase (CSP) based on (3,3′-diphenyl-1,1′-binaphthyl)-20-crown-6 covalently bonded to silica gel. The resolution was quite good, the separation (α) and resolution factors (RS) being 1.84–15.32 and 1.34–13.78, respectively. Especially, the result for the resolution of tocainide on the CSP turns out to be the best one among others reported so far. The chromatographic resolution behaviors were demonstrated to be dependent on the content and the type of organic and acidic modifiers and the ammonium acetate concentration in aqueous mobile phase.