The characteristics of open-tubular capillary electrochromatography columns with series/mixed stationary phases constructed with magnetic nanoparticle coating

► We report OT-CEC columns with series/mixed stationary phases constructed by magnetic field. ► The best column efficiencies of both series/mixed OT-CEC columns exceed 400,000 plates/m. ► The stationary phase can be easily regenerated by removing and re-applying the magnets.