Abstract: Preliminary results indicated that good separation of ions of sodium, potassium, rubidium and caesium could be achieved by means of high-performance liquid chromato-graphy in ten minutes, with a column filled with 5% dibenzo-18-crown-6 in chloroform on YWG-CH. A solution of 0.2 M sodium thiocyanate (pH 6.5) was used as the eluant and 24Na, 42K, 86Rb and 134Cs were used as tracers to indicate the course of column operation.