The factors limiting sensitivity of radiochemical methods of analysis and the ways of overcoming these limits are discussed. Sensitivity and selectivity of different radiochemical methods are compared by way of model calculations. Some new sensitive and selective methods of analysis are proposed as well as their combination with substoichiometric preconcentration.
The possibilities of the radioactive reagent method are surveyed. Equations are derived which allow to calculate, the error
of analysis in different variants of the method, as well as equations for the calculation of pHmin and the minimum determinable concentration of a test element.
New equations are derived which allow to apply the radioactive reagent method even if the test element interacts with the
labelled reagent incompletely. These equations allow to widen considerably the range of permissible relative quantities of
reagents (up to the use substoichiometric quantities) and permit to increase the sensitity of analysis.
A group of radiochemical methods of analysis is considered, in which the change of test element-reagent ratio is attaining by means of isolations with equal quantities of reagent from multiple volumes of analyzed solution. These methods allow to apply non-isotopic radioindicators and radioactive reagents and allow to increase considerably sensitivity and selectivity of determinations in comparison with substoichiometric methods of isotope dilution and radiometric correction.
A group of radiochemical methods of analysis is considered in which a change in the test element-reagent ratio is created by means of addition of known quantities of test element to aliquots of analyzed solution. These methods allow to use non-isotopic radioindicators and radioactive reagents, and allow considerably to increase sensitivity and selectivity of determinations in comparison with substoichiometric methods of isotope Dilution and Radiometric Correction.
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.
Some new radioisotope methods of analysis, applying radioactive reagents are elaborated. These methods considerably increase
the sensitivity of the determinations in comparison both with the classical radioactive reagent method and with the analogous
Two new radioisotopic methods of analysis have been worked out. They apply a radioisotope label in the test element and a
partial separation of the latter with different quantities of unlabelled reagent. The sensitivity of the new methods is higher
than that of the previously known radioisotopic methods of analysis.
A new radioisotope method of analysis has been worked out, in which both test element and reagent are labelled with radioactive
isotopes. The new method is of high sensitivity and can be applied in cases when the degree of interaction between reacting
substances is very low and when separation of a substance formed into the second phase is incomplete.