Applications of Radioactivity:

You have studied fundamentals of radioactivity, decay laws, measurement methods and methods of production of radioisotopes and radiotracers including its availability. In this unit you will study about applications of radioactivity which has found wide applications in basic researches in physics, chemistry, biology and medicine including agriculture, industry, nutrition research, environment related research, forensic science etc. Therefore, in this unit we will limit ourselves mostly with analytical applications of radioisotopes. In common, nuclear analytical methods based on the measurement of radioactivity might be classified within two wide groups: first based on the direct measurement of radioactivity in the system and second by making it radioactive by the bombardment of the sample in a nuclear reactor or accelerator facility or by adding radioactivity in the system. A broad classification of various nuclear analytical methods is presented in Figure. Ever because the discovery of radioactivity, several techniques such as neutron activation analysis (NAA), isotope dilution analysis (IDA), radiochromatography (RC), radiometric titration (RT), radioimmunoassay (RIA), etc have been developed during last few decades.  Out of all these methods, NAA is the most common. It is primarily based on the principle of irradiation of the sample with a neutron beam in a nuclear reactor and thus making it radioactive. Therefore, in case of radiotracer techniques such as IDA, RT, RC and RIA sample is made radioactive by the addition of radiotracers of suitable radiation type and half life. A comparative account of advantages and limitations of each of the techniques will be presented.