By Sunil Bhardwaj


Isotope dilution analysis is a method of determining the quantity of chemical substances. Generally Naturally occurring compounds contains their isotopes also, but the quantity of the isotope is so small that their detection is almost impossible. Also Both the isotopes behave same to any chemical reaction, thus they can not be detected by any chemical method.

So if a known quantity of a radioactive element is added to the sample. The radioactivity of sample increases. And by comparing the initial and final radioactivity of that sample we can easily detect the amount of radioactive isotope present initially in the sample.

This technique of putting (doping) little radio active isotope to non-radioactive compound of the same is known as Isotopic dilution.

The radio active compound which is obtained is known as labelled compound, or tagged compound (or) Tracer.

When a little quantity of Radio-active lead 210Ra is mixed with the larger quantity of PbSO4 It is known as Isotopic dilution. Now. PbSO4 which is obtained is known as labelled.(or) tagged (or) tracer.