Graph-Calculation Method of analysis has been developed. The new method considerably increases (in comparison with Radioactive
Reagent Method) the sensitivity of determinations and allows to enlarge the list of suitable reagens as well as permissible
limits of relative quantities of radioactive reagent applied. The equations have been derived which allow to calculate the
degree of interaction of the reacting substances and to carry out model calculations for any radioisotope method of analysis
applying radioactive reagents.