For the anionic resins, pass the three extracting solvents (4.1, 4.2 and 4.3) separately through the prepared columns (6.1) at a flow rate of 350 to 450 ml/h. Discard the first litre of eluate in each case and collect the next two litres in measuring cylinders (5.2). For the cationic resins, pass only solvents 4.1 and 4.2 through the columns prepared for this purpose.
