Los Alamos National Laboratory Report LA-1315

Bismuth analytical methods were investigated for the purpose of selecting procedures which are satisfactory for the analysis of solutions containing plutonium and bismuth. The gravimetric procedure which is recommended for samples containing these two elements includes removal of the plutonium by peroxide precipitation, separation of the bismuth by precipitation with sodium carbonate, and final ignition of the bismuth as a phosphate. Necessary equipment and experimental technique are described. In the analysis of eight known samples by the recommended method, the average recovery of bismuth was 99.76 percent, with a standard deviation of 0.22 percent. The known samples contained about 35 mg of bismuth and 25 mg of plutonium. For similar samples in routine work, the confidence limits at the 95 percent level for the average of triplicated determinations are +- 0.30 percent of the bismuth in the the sample. Other methods investigated and having possible application for some Pu-Bi analysis problems include electrodeposition of bismuth on a mercury cathode and gravimetric analysis with BiCr(CNS)6 as the weighed product