Abstract
Results are repoerted for238U,234U,232Th, and230Th determinations in 19 rock samples from a uranium mine, performed independently, byb three different laboratories. Uranium and thorium isotopoic activities were determkined by alpha spectrometry, after different pre-concentration and counting sample preparation techniques., Additionally, total concentrations of uranium were determined by fluorimetry and gamma spectreometry. the folloing conclusions could be drawn from this intercomparison test: (1) The results for238U specific activity agreed with the amjority of results within 10%. Lincar correlation coefficients between the three data sets were 0.999. However, for a few samples of much higher uranium concentrations, large deviations were observed, indicating problems of, sample heterogencity. (2) For the234U/238U activity ratio data, a still closer agreement was obtained (5%), as computation of the activity ratios did not, require information on the yield of the used tracer spike (232U). (3) The results for232Th specific activities and230Th/234U activity ratios showed larger deviastions between the three laboratories (typically up to 15%, in some cases still ore). Different Th-isotopes (228Th,234Th and229Th) have been used as yield tracers. The data indicates, however, that the observed deviations are not simply a consequence of a systematic difference in the calibration of the different spikes, but, probably cased by other errors such as incomplete sample dissolution, sample heterogencity, tec. The limitations of alpha spectrometry will be discussed and an application of the developed methods shown.
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K. OSMOND, J. B. COWART, Groundwater, M. IVANOVICH, H. HHARMON (Eds), Uranium Series Disequilibrium: Applications to Environmental Problems in the Earth Sciences, Oxford University Press, Oxford, 1982, p. 202.
J. K. OSMOND, J. B. COWART, M. IVANOVICH, Intern. J. Appl. Radiation Isotopes, 34 (1983) 283
A. B. MACKENZIE, R. D. SCOTT, P. LINSALATA, N. MIEKELEY, J. K. OSMOND, D. B. CCURTIS, Poço de Caldas Report, NAGRA NTB 90-25, 1991, p. 185.
A. B. MACKENZIE, R. D. SCOTT, P. LINSALATA, N. MIEKELEY, J. Geochem. Explor., 45 (1992) 289.
J. N. ROSHOLT, B. R. DOE, M. TATSUMOTO, Geol. Soc. Amer. Bull., 77 (1966) 987.
M. P. BACON, J. N. ROSHOLT, Geochim. Cosmochim. Acta, 46 (1982) 651.
L. HALLBERG, H. BRISE, S. ANDERSON, A. TELC, Intern. J. Appl. Radiation Isotopes, 89 (1960) 100.
P. LINSALATA, E. PENNA FRANCA, I. SSACHETT, M. B. DE CASTRO, N. LOBÃO, R. BALLAD, W. LEI, R. MORSE, H. FORD, M. EESENBUD, CONF 841142 NTIS, Springfield, VA, USA, 1987, p. 131.
C. W. SILL, R. L. WILLIAMS, Anal. Chem., 53 (1981) 412.
C. W. SILL, C. P. WILLIS, Anal. Che., 34 (1962) 954.
C. L. PORTO DA SILVEIRA, geoquímica da mineralizacão metassomática urano-sódica de Espinharas (PB), Doctoral Disseration. Pontificia Universidade Cat'olica do Rio de Janeiro, 1986, 287 p.
N. MIEKELEY, M. G. R. VALE, C. L. PORT DA SILVEIRA, Inorg. Chim. Acta, 140 (1987) 321.
H. COUTINHO DE JESUS, Desequilforios radioativos em águas e rochas e outros aspectos geoquímicos da mina de urânio Osamu Utsumi e do depósitoi torffero Morro do Ferro, Poços de Caldas (MG). Master Dissertation. Pontifícia Universidade Católica do Rio de Janeiro, 1989, 200 p.
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Mackenzie, A.B., Scott, R.D., Linsalata, P. et al. Interlaboratory comoparison of analytical methods for the determination of natural series uranium and thorium isotopes in rock samples. Journal of Radioanalytical and Nuclear Chemistry, Articles 182, 21–34 (1994). https://doi.org/10.1007/BF02047962
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DOI: https://doi.org/10.1007/BF02047962