Evaluation of the extractive procedure for determination of ~(238)U ~(234)U in groundwater and comparison with traditional α-spectro technique

摘要

Photon/Electron Rejecting Alpha Liquid Scintillation (PERALS~?) spectrometry has been usdetermination of uranium radionuclides in the ground water samples. The technique utilizes a comavailable extractive scintillant URAEX~?, which is selective for uranium. The cocktail extracted uranaqueous medium quantitatively and the efficiency of extraction was nearly 100% with no self-absogeometry problems. This method applies to pulse-shape discrimination of PERALS~? counting spectromcompletely separates the alpha activity from the beta/gamma background. The resolutions of the ~(238)U,~(232)U obtained in this method were good enough to for measurement of uranium isotopes in a quantitaThe lower limit of detection was found to be 2.0 mBq l~(-1) for 2 hours counting time for a sample volumml. The levels of ~(238)U and ~(234)U concentrations in groundwater samples of several locations were foundfrom 12.8 ± 1.0 to 148.3 ± 10.8 mBq l~(-1) and 16.1 ± 1.2 to 106.7 ± 8.2 mBq l~(-1), respectively. For thdrinking water samples collected from markets, the ~(238)U and ~(234)U concentrations were found to range frodetectable level (BDL) to 38.7 ± 2.4 mBq l~(-1) and 47.3 ± 2.8 mBq l~(-1), respectively. The results ofradionuclides (~(238)U and ~(234)U) in groundwater and bottled water samples measured by PERALS? metcompared with that obtained by alpha spectrometric method.