Determination of radiostrontium in environmental objects by extraction chromatography using tvex-DCH18C6

A new method for the rapid isolation of strontium radionuclides from environmental objects is described. The method is based on the selective extraction of strontium with a solution of dicyclohexyl-18-crown-6 in tetrachloroethane from nitric acid solution. The usage of this process in extraction chromatography permits to isolate strontium radionuclides with contamination coefficients not less than 10²–10³. A highly porous matrix of a copolymer of styrene and divinylbenzene is used as support. The method includes the following steps: nitric acid leaching of the sample calcined at 500–600°C with final adjustment to 1.5–2.0M HNO₃; elution of nitric acid extract through the extraction chromatographic column; washing of the column with 1.5–2.0M HNO₃; desorption of strontium with hot water, precipitation of strontium carbonate and measurement of -activity of the precipitate.