Dionex EPM 500 consists of a cation exchange bed equipped with an anode at the outlet. The inlet end of the device is connected to the cathode via a cation exchange connector. DC current is applied to the Dionex EPM 500 to remove controlled amounts of potassium ions, which are forced to migrate through the cation exchange connector. The displaced potassium ions move toward the cathode, combine with hydroxide ions to form a potassium hydroxide solution, and are then discharged into the waste liquid. At the same time, hydronium ions generated at the anode can convert carbonate into bicarbonate. By controlling the applied current, the pH of the incoming potassium carbonate eluent can be changed to form potassium carbonate and potassium bicarbonate solutions (used as eluents in IC separations).