Analytical Reactions of Rubidium and Caesium

Determination of Low Concentrations of Radioactive Cesium in Water

“…Neither cesium nor a combination of cesium and potassium tetraphenyl-.boron settled under the conditions reported to be most favorable for precipitation (8); hence this precipitation was not considered further. Although the phosphomolybdate settled completely in approximately 12 hours, decanting after 4 hours resulted in a cesium loss of only 15%, and was considered feasible. The phosphomolybdate precipitate does not form in the absence of cesium, and appears to have a consistent cesiumammoniumphosphorus-molybdenum ratio of 1.8:1.2:1.0:12.0.…”

“…This model has a nominal voltage of 24 volts. Other models having nominal voltages of 1.5, 6, and 12 volts are available from the manufacturer. A wooden motor mounting was used to eliminate magnetic effects.…”

“…by careful heating. Considered for cesium determination were precipitation from liter volumes of water of relatively insoluble cesium ammonium phosphomolvbdate, mixed cesium sodium potassium cobaltinitrite, and cesium and potassium tetraphenylboratc {9, 12,16) and the absorption of cesium on an ion exchange resin and subsequent elution by a small volume of acid. The methods found effective were combined with a decontamination procedure in current use (•5), and tested with radioactive cesium tracer and with a mixture of long-lived fission products.…”

Absorptiometric Method for Determination of Cesium

“…Potassium and limited amounts of rubidium can be present. Another heteropoly compound, tungstosilicic acid, was used as a precipitant for cesium (8,9,11). O'Leary and Papish (11) recommended it for the quantitative separation of cesium from rubidium, but because of the uncertain hydration of cesium tungstosilicate, cesium must be reprecipitated as the chloroplatinate before being weighed.…”

“…Another heteropoly compound, tungstosilicic acid, was used as a precipitant for cesium (8,9,11). O'Leary and Papish (11) recommended it for the quantitative separation of cesium from rubidium, but because of the uncertain hydration of cesium tungstosilicate, cesium must be reprecipitated as the chloroplatinate before being weighed. In determining cesium radiometrically, Kahn (9) separated cesium by precipitation with tungstosilicic acid.…”