This paper describes a study about the quantitative separation of cations and anions of the aqueous solution contain ing ferric iron, calcium, magnesium, potassium, sulfate and phosphate, employing a column formed by a resin bed (Dowex 50 -X8). The cation retention was studied by using solutions of pH 1.85; 1.00; 0.60 and 0.20. The retention was good for the pH 1.85 to 0.60 for all the cations studied. The elution of the cations with three five mililiters portions of 4 N HCl solution showed good results. Sulfate and phosphate were recuperated after the solution was passed through the column of resin, washing the resin with two mililiters of water. The results obtained allow to conclude that the technique is satisfactory for the separation of cations and anions of the plant materials extracts.