B. Chemistry on each air filter composite which contains only paperfilters. 1. C. Proceed with the Plutonium In Coral Soil (DOE/ERSP Procedure No. 10) starting at Step No. 1. Chemistry on each air filter composite which contains glass fiber filters. 1. 2. Transfer the filter quarters to a 250 ml Teflon beaker containing 8M HNOg and a Teflon stirring rod. Add 236 py tracer. Transfer the sample from the Chemistry Trailer to the outside perchloric acid hood. Add: 20 ml HC104, 50 m1 1M HF and 10 ml 8M HNOg. Place on Corning hotphate (setting 5) and reduce volume until dense white HC10, fumes are given off. Remove from hotplate and cool. Dilute with 10 ml of 8M HNO3. Add 5 - 10 ml HC1l0,4 and 50 mi HF and again reduce volume until HClO4 fumes appear. Repeat Step 5 until all silica appears to have been destroyed. Transfer sample back into original 250 ml Pyrex beaker using 8M HNO3 as needed. Take sample to dryness and continue heating carefully to avoid spattering. Heat until most of the dense white HClO4 fumes are no longer present. Rinse the sides of the beaker with 8M HNOg and repeat Step 8 until HC1O4 fumes are no longer given off. 10. Remove sample from perchloric hood and return it to the Chemistry Trailer. Add 30 ml of 8M HNOg and proceed with Step 2 of the Plutonium In Coral Soil (DOE/ERSP Procedure No. 10). A-26-2