UNC LASSIFISD ANALYTICAL PROCEDURES FOR DETERMINATION oF cR°? BY N AND COUNTING oF y®° . at After the sample en the brass ‘slls **s been ccunted for total strontium and has reached equilibrium, it may be wed * Seae at wes ~~ -< . we ew 2 at tor Y°° separation. Ze Countthe sample and record data. }e Remove the sample from the brass holder. Wash the holder with about 25 ml of water. Allow washings to fall into beaker with the bulk of the parer. be Bring to a boil and filter thru No. lil paper into a D al platimm dish. Wash the beaker and paper with aovroximate- ly 15 mi more of water. 5e Evaporate to dryness on a sand bath. Add approximately 20 ml of HF and evaporate to dryness again. Pick up the residue with approximately 5 drops of HCl. Transfer to a beaker with water. Bring volume to about DW nl. A 10 mg of lanthanum carrier. (This carrier sust have negligibje p activity). Te Bring to a boil and adjust pH to 6-7. Allow to stand for abogt 1S minutes and filter thru a 1-1/8 glass fiber paper. Place brass holder. Cover with pliofila and count. Record time that filtration was completed. counting date and counting time. I Count and record Ooserve decay by counting at approximately 3-day intervals for a period af about 12 days. The procedure was tes:ed by measuring the recovery of Y°? added tol Solutions containing 20 mg of Sr as the mitrate. The recoveries found with either paper or glass fiber filters were 94-99%. mis GS UNC LASSIFIzD 00131986.056 103 1085