APPENDIX H PROCEDURES FOR PRECIPITATION OF 1. The sea water was acidified and stirred to remove bicarbonates. 2. Ferric chloride was added and precipitated by the addition of ammonium hydroxide. The precipitate was allowed to coagulate. 3. Saturated ammonium oxalate solution was added to the solution to precipitate oxalates, and the solution was aliowed to stand several hours. 4. The combined precipitates were filtered, and the filter paper with precipitate was returned to the laboratory. Processing in the laboratory was as follows: 5. The filter paper and precipitate was ashed at 600°C to destroy the paper and convert oxalates to oxides. 6. The ash was dissolved in dilute hydrochloric acid. Solution was complete. 7. The iron which had previously been added was reprecipitated by the addition of ammonium hydroxide. This precipitate, which is believed to contain most of the fission products of the sample, was plated and counted, 8. The alkaline filtrate was diluted to 100 ml, and duplicate 20-m! aliquots were taken. 9. The aliquots were diluted to 100 ml, and calcium and strontium were reprecipitated by the addition of saturated ammonium oxalate solution. The precipitate was plated and counted. The 0.5-liter postshot samples were brought to the laboratory for all the processing. The method was slightly different from that used in the field and was as follows: 1, The sample was acidified and stirred to remove bicarbonates. 2. Ferric chloride was added and reprecipitated as ferric hydroxide by the addition of ammonium hydroxide. The precipitate was filtered out, dissolved, and washed through the filter paper with dilute acid, reprecipitated from a smaller volume, centrifuged, plated, and counted. 3. Calcium and strontium were precipitated from the alkaline filtrate by the addition of saturated ammonium oxalate solution to the hot solution, The precipitate was filtered out, dissolved, and washed through the paper with acid, reprecipitated from a smaller volume, centrifuged, plated, and counted. IMreCLASSITED |ceoeme $4 = ve Av,ins gts = FISSION PRODUCTS AND CALCIUM AND STRONTIUM