Determination of radium isotopes in mineral and environmental water samples by alpha-spectrometry

Critical comparison of radiometric and mass spectrometric methods for the determination of radionuclides in environmental, biological and nuclear waste samples

“…Although the resolution of semiconductors for α−spectrometry is good, the relatively small difference in alpha particle energy between some alpha emitters makes it difficult to spectrometrically separate the peaks. This is usually the case with isotopes such as 241 Am and 238 Pu, and 237 Np, 233 U, 234 U and 230 Th. It is therefore that a good chemical separation of radionuclide of interest from the matrix is required; otherwise, the self-absorption of α particles in the source will not only reduce the counting efficiency, but also worsen the energy resolution of the α spectrum.…”

“…Several review articles have addressed the applications and limitations of ICP-MS for the determination of radionuclides [2][3][4][5][6][7][8][9]. Because of the high sensitivity, short analysis time and relatively easy operation, ICP-MS has been widely used for the determination of isotopes of uranium, thorium, and plutonium, 79 Se, 90 Sr, 99 Tc, 129 I, 135 Cs, 210 Pb, 226 Ra, 228 Ra, 231 Pa, 237 Np, 241 Am, 243 Am, and 244 Cm in environmental and waste samples .…”

“…In GDMS, an argon gas glow discharge at a pressure of 0. 237 Np, 137 Cs, and 90 Sr [117,118]. Since the sample is directly analyzed, the sample preparation is very simple, which minimize the risk of contamination.…”

“…The 228 Th generated from 228 Ra is then measured by α-spectrometry. The advantage of this method is the simultaneous determination of 224 Ra, 226 Ra and 228 Ra, and a relatively low detection limit (0.2 mBq) [237]. The drawback is the very long analytical time (1-2 years) due to the long waiting time for the in-growth of the longer-lived 228 Th (1.9 y).…”

“…Neptunium-237 presenting in environment has been produced by 238 U(n,2n) 237 U→ 237 Np reaction through fast neutrons in nuclear bomb testing and reactors and 235 U(n,γ) 236 U(n, γ) 237 U→ 237 Np reaction in nuclear reactors followed by releases from spent fuel reprocessing. It is also produced as a consequence of the decay of 241 Am.…”