Chapter 8
Sample Preparation for Counting
8.1 Sample Preparation Techniques
Radioactive nuclides separated by any radiochemical techniques will probably need
to be counted. The separated material cannot be simply put near the counter and
counted. A special technique is required to prepare a suitable source for counting. In
this chapter, various modes under which a radioactive material can be counted and
importance of source preparation for counting activity of the radioactive sample is
presented.
8.1.1 Counting of Solutions
Counting of radioactive materials by liquid scintillation method is difficult when
they are not soluble or miscible with the liquid scintillator. In some cases, insoluble
substance is forced to dissolve, by addition of a lipoidal base or acid to form toluene
soluble salt. Some metallic cations are converted to toluene soluble complexes by
treatment with a suitable chelating agent. When several sources are to be compared,
care is needed to ensure that quenching is either absent or maintained constant in all
samples. However, liquid sample for liquid G.M. counter does not need any special
preparation, except corrections for density, volume of liquid, etc.
8.1.2 Counting in Form of Suspension
Sometimes, either it is not desirable to dissolve a material in any solvent or not
possible to dissolve in a suitable solvent (solvent which does not cause quenching
in scintillation counter). In such cases, the following technique can be adopted. A
suspension of fine powder of a material is made by means of some suitable gelling
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
M. Sharon and M. Sharon, Nuclear Chemistry,
https://doi.org/10.1007/978-3-030-62018-9_8
139
Sample Preparation for Counting
8.1 Sample Preparation Techniques
Radioactive nuclides separated by any radiochemical techniques will probably need
to be counted. The separated material cannot be simply put near the counter and
counted. A special technique is required to prepare a suitable source for counting. In
this chapter, various modes under which a radioactive material can be counted and
importance of source preparation for counting activity of the radioactive sample is
presented.
8.1.1 Counting of Solutions
Counting of radioactive materials by liquid scintillation method is difficult when
they are not soluble or miscible with the liquid scintillator. In some cases, insoluble
substance is forced to dissolve, by addition of a lipoidal base or acid to form toluene
soluble salt. Some metallic cations are converted to toluene soluble complexes by
treatment with a suitable chelating agent. When several sources are to be compared,
care is needed to ensure that quenching is either absent or maintained constant in all
samples. However, liquid sample for liquid G.M. counter does not need any special
preparation, except corrections for density, volume of liquid, etc.
8.1.2 Counting in Form of Suspension
Sometimes, either it is not desirable to dissolve a material in any solvent or not
possible to dissolve in a suitable solvent (solvent which does not cause quenching
in scintillation counter). In such cases, the following technique can be adopted. A
suspension of fine powder of a material is made by means of some suitable gelling
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
M. Sharon and M. Sharon, Nuclear Chemistry,
https://doi.org/10.1007/978-3-030-62018-9_8
139