A new and general method of inducing a precipitation from homogeneous solution has been applied to the separation of barium and strontium. The precipitation of barium bromate, a water-soluble compound, is brought about by a gradual change in the composition of the solvent media. An organic compound, such as methanol or tetrahydrofuran, is allowed to diffuse into the original water solution, thus slowly converting the solution into a water-organic mixture. Strontium bromate is about 40 times more soluble in water than barium bromate. The increased solubility plus the greater stability of the strontium MEDTA chelate tend to hold the strontium in solution. The chief advantage of this method over the precipitation of barium chromate is in the preparation of barium compounds. Usually barium must be separated from the chromate before proceeding. However, barium bromate can be easily converted to the oxide, eliminating this separation step.