UNCLASSIFIED ANALYTICAL PROCEDURE FOR THE SEPARATION AND DETERMINATION OF RADI(M IN 100 GRAMS OF SOIL 1. Except for the addition of 20 mg of Sr** carrier, Steps 1 thru 18 of the grb? 9° procedure are carried out exactly the same Way. _ @e When the carbonate precipitate is dry, remove from the filter paper and transfer to a pyrex glass tray. 3. Place in a 100°C oven and dry overnight. 4. Now break up the aggregated material with a spatula and crush S. Return the material to a 100°C oven and dry again. 6. Finally place the dried precipitate in a copper radon collecting tube. Plug up both ends with pyrex wool, flush out the as well as possible with a pestle. tube with hydrogen and then seal. 7. Record the time. For full equilibrium, allow a 30 day build, but shorter buildup times are useable. Measure the radon in an ionization chamber radon counting apparatus. This method of radon collection is relatively wtried, but a spiked sample gave the following result, g Ra per g Soil Sample Added Found Soil No. 114 0 5.2 x 10729 won 8.4 x 1074? 4 x 10739 Spiked soil No. 11h 4.0 x 107%? dwt CG UNCLASSIFIED j rence