Procedure — Lo Weigh out 500 em. aliquots of the blended material into 3 liter beakers . Add 200 mg of strontium carrier and carrier-free strontium tracer§2®) Be Stir mechanically while slowly adding one liter of 6N HCl solution. (It may be necessary to add a few drops of octyl alcohol to prevent excessive frothing.) h, Continue stirring for about 30 minutes. Allow a minimm of two hours for the insoluble material to settle. Stir the mixture and filter with suction through a 24 cm No. 5 Whatman peper using a Buchner funnel. Wash the soil residue with hot distilled water. Wash the residue with 6N HCl and again with hot distilled water until the yelley color of iron (ITI) chloride is removed. Discard the residus. Transfer the Piltrate to a 3 liter beaker and evaporate to approximately 506 ml. Je Cool and add one liter of HNO. (If there is excessive frothing, add a few drops of octyl alcohol.) 106. Evaporate to approximately 300 ml. Add 500 mi of distilled water and stir. Allow to cool and filter with suction through an 11 cm giass fiber filter to remove the silica. tere" = 7 -| (156) The tracer must be checked to be certain that there is no contezuination in the foun of extraneous 4 activity. - 25 -