Y-90 IN CORAL SOIL DATE DRAFTED: 30 January 1978 DOE/ERSP PROCEDURE NO. 15 APPROVED: IL 15 February 1978 by Don R. Martin (ERSP Manager) Introduction The method used to arrive at a 90sr value is derived by assuming that secular equilibrium of the 90y daughter has been achieved and remains in the coral soil. Strontiumrecovery is assumed to be 100 pereent. The only separation time the chemist need be concerned with is the SrY separation during the extraction (T9). Reagents Il, 8M HNO3 NH4OH (carbonatefree) Yttrium carrier 9M HCl 0.08M HCl Saturated (NH4)gC904 5% HDEHP in toluene Methyl red indicator 3M HNO3 Ethanol Procedure Ash 1 to 2 g of coral soil in a muffle furnace at 700°C for 4 hours. Transfer the sample into a 250ml beaker with 25 ml of 8M HNO3. Add the desired amount of yttrium carrier (normally 20 mg). Dissolve the sample by boiling, then evaporate to near dryness, NOTE: Excess residual acid should be avoided. The extraction of yttrium into HDEHP is dependent on a low acid concentration. Allow the sample to cool. Dissolve the sample with 25 ml of 0.08MHCl1 by warming gently. Transfer the sample to a 125 ml separatory funnel. Rinse the beaker with 5 ml of 0.08M HCl and add the rinse to the funnel. Add 30 ml of 5% HDEHP in toluene to the separatory funnel and shake for 2 minutes. Record the extraction time and date as Ty. and discard. Drain the 0.08MHCI1 from the funnel Add 30 ml of 3M HNOz to the sample. Shake the sample for 2 minutes and allow the phases to separate. Drain the 3M HNO3 into a 40 ml centrifuge tube. Add cone NH4OH to the sample while stirring to precipitate Y(OH)3. Digest the sample in a hot water bath until the precipitate coagulates. Centrifuge the sample and discard the supernate. Dissolve the Y(OH)3 in 2-3 ml of 9MHCI1. Dilute the sample to 10 ml with deionized water and filter the sample into a clean 40 ml centrifuge tube. Add methyl red indicator to the sample and neutralize the sample to the end point by the addition of NH4OH. 2 drops excess 9M HCl. Make the solution just barely acid with 9MHCl, A-15-1 Add