A new method for the radiochemical separation of rubidium and cesium

The analytical reactions of bismuth iodide and stannic chloride with cesium and rubidium are used for the radiochemical separation of these two elements. The method consists in precipitating potassium, rubidium and cesium as their cobaltinitrites, selective isolation of cesium as cesium bismuth iodide from glacial acetic acid, and subsequent separation of rubidium from potassium as chlorostannate from conc. HCl. The results obtained by the present method for the rubidium and cesium contents of the different U.S.G.S. standard rock samples are compared with those reported using methods of comparable accuracy. The suitability of the method for the analysis of fall-out samples for their radiocesium (¹³⁷Cs) contents has been demonstrated.