Extraction by polyhedral complex compound of the formula H+ [(π-(3)-1,2-B9C2H11)2Co−] further on referred to as dicarbolide-H+ and its chloro-derivate H+[B18C4H15Cl7Co−] further on referred to as Cl-dicarbolide-H+ in nitrobenzene was used for the analysis of137Cs in urine and faeces after internal contamination. The dependence of distribution ratio on the acidity of analysed solutions
was determined. The effect of urine dilution was assessed as well as the effect of various concentrations of the extraction
agents on the distribution ratio of137Cs. The effect of phase ratio at the different concentrations of isotopic carrier was assessed, as well as the effect of potassium
ions on the decrease of the distribution ratio at the extraction of137Cs by dicarbolide-H+ or its chloro-derivate. The possibility of isolation of137Cs by extraction and the isolation of137Cs by ion-exchange absorbents and by ammonium molybdophosphate was compared. The values of distribution coefficient were determined
at various concentrations of nitric acid and the isotopic carrier. The dependence of coextraction of some activated radionuclides
and fission products by dicarbolide-H+ on the nitric acid concentration in the solute was determined. The effect of mass of contaminated faeces on the value of
the distribution ratio of137Cs by the extraction was evaluated. As a result, a suggestion was given for the rutine isolation procedure of137Cs extraction with dicarbolide-H+ from the excreta contaminated by a mixture of radionuclides.