Procedure 20. Determination of Pu

This procedure used an oxidized CeF -reduced LaFg cycle and extraction of Pu(VI) into hexone. in addition to two cycles of adsorption of Pu(IV) on anion resin from concentrated HCl and desorption by reduction with NH I. 

Add 5 mg Fe and 1 ml HNO to the acid solution containing the Pu activity. Boil the solution down to about 3 ml and transfer to a 50-ml lusteroid tube, 

Make the solution ammoniacal to precipitate Fe(OH)g, Digest for a few minutes on a 7 5 C water bath. Wash the hydroxide with 5 ml water containing 1 drop NH OH. Discard the supernate and wash. 

Precipitate CeF by adding 10 drops HP treated with dichromate (Note b). Stir well and centrifuge immediately. Wash the precipitate with 2 ml 1 N HNOg 1 N HF. Decant the supernate and wash into a clean 50-ml lusteroid tube. 

IMake the solution basic with 8 N NaOH. Let stand 3 min and centrifuge. Wash the Fe(OH)j with 10 ml water. Discard the supernate and wash. Dissolve the hydroxide in 3 drops of HNOg. 

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