Routine analysis of naturally occurring radionuclides in environmental samples by alpha-particle spectrometry
Supervising Scientist Report 180
P Martin & GJ Hancock
Department of the Environment and Heritage 2004
ISBN 0 642 24386 7
- SSR180 - Routine analysis of naturally occurring radionuclides in environmental samples by alpha-particle spectrometry (PDF - 1250 KB)
The high sensitivity and wide range of applicable sample types make α-particle spectrometry a powerful technique for the determination of low-level activities in environmental samples. Radiochemical techniques are described here for the determination of the following α-emitting radionuclides:
234 U, 235 U and 238 U
228 Th, 230 Th and 232 Th
223 Ra, 224 Ra and 226 Ra, and
together with a method for the determination of 210 Pb by ß counting. In addition, the ß-emitters 228 Ra, 210Pb and 227Ac can be determined within a few months of their separation from the sample digest by measurement of their α-emitting progeny.
After addition of a suitable tracer and dissolution of the sample, a chemical separation scheme is used which allows the sequential separation and analysis of radioisotopes of U, Th, Ra, Pb, Po and Ac on the same sample digest. This scheme has been developed with the aim of achieving consistent high chemical yields while minimising analysis time.
Sample pretreatment criteria, tracer isotope selection and spectrum analysis procedures for each element are discussed, and typical spectra shown. A set of computer programs used for the calculation of results are also described.
This report updates and replaces an earlier report on this topic (Martin & Hancock 1992, Research Report 7).