s . m ed - p h ] 1 1 Fe b 20 01 Extraction of 137 Cs by alcohol - water solvents from plants containing cardiac glycosides

As a result of nuclear power plant accidents, large areas receive radioactive inputs of 137 Cs. This cesium accumulates in herbs growing in such territories. The problem is whether the herbs contaminated by radio-cesium may be used as a raw material for medicine. The answer depends on the amount of 137 Cs transfered from the contaminated raw material to the medicine. We have presented new results of the transfer of 137 Cs from contaminated Digitalis grandiflora Mill. and Convallaria majalis L. to medicine. We found that the extraction of 137 Cs depends strongly on the hydrophilicity of the solvent. For example 96.5%(vol.) ethyl alcohol extracts less 137 Cs (11.6 %) than 40%(vol.) ethyl alcohol or pure water (66.2 %). The solubility of the cardiac glycosides is inverse to the solu-bility of cesium, which may be of use in the technological processes for manufacturing ecologically pure herbal medicine.