40+ Level of stabie } . | = L = 4020 bismuth carrier—> fT T t+ or 30 Qa. ” 2 Oo me ik O15 r ut ' Zz<I © 20+ 10 B z Oo 3 | z or | . g Bi - ; lOF 0-05 nO 5 see ia ! t 15 25 35 45 55 65 76m. [Sample |2.N Vig. 1. aad x= 2 a |6N [ren __fheo| The elution curve from ‘Dowex-1' of bismuth carrier and bismuth-207 previonsly separated ou a ‘Dowex-s0" fonexehanve column from a sample of alva cuilmeted af Eniwetek Atoll in March 1961. The dashed dine is the elution curve for the bismuth earrier in which the levels of bisinath were determined by the iudide colorimetric test. The solid line uidientes the » activity of bismuth-207 in the eluted fractions, 96 per cent confidence-levels for counting error ire given The The y-speetrum made from the anion fraction contained the photopeaks of ruthenium-106-rhodium106 and bismuth-207. 98 per cent of the bismuth-207 was recovered in this fraction. and the remaining bismuth-207 was eluted in the oxalate fraction. After removal of the ruthenium from the anion fraction by distillation with perehlorie acid only the photopeaks of bismuth-207 were present in the y-spectruin. An iodide colorimetric test for bismuth was made after removal of the ruthenium!, The sample was dissalved in 10 ml. of 2 8’ sulphuric acid. Five ml. of 1 per cent ascorbic acid together with 1 ml. of | per eent sodium sulphite. then 1 ml. of 10 per cent potassium iodide were added to three drops of ihe saunple in 10 ml. of 2.Nsulphuric acid. The solution exhibited the orange colour of iodobismuthite.