DETERMINATION OF URANIUM IN BIOASSAYS BY ICP-MS AND LA-ICP-MS
(THE SAGA OF A FAMILY)
Hagit Sela 1,3, Zeev Karpas 1, Ofra Paz-Tal 1, Abraham Lorber 1, Yossi Hgag 1, Laina Salonen 2 Maarit Muikku 2 and J. Sabine Becker 3
1 Nuclear Research Center, Negev, P.O.Box 9001, Beer-Sheva, Israel 84190
2 STUK—Radiation and Nuclear Safety Authority, Research and Environmental
Surveillance, P.O.Box 14, FIN-00881 Helsinki, Finland
3 Central Division of Analytical Chemistry Research Centre Juelich, D-52425
Juelich, Germany
Determination of uranium concentration and isotope ratios is required for environmental monitoring of nuclear contamination in nuclear safeguards and nuclear forensic studies, for analysis of biological, medical and geological samples, soils, dust, water and also food. In this paper the concentration of uranium in urine, hair, and nails due to continuous exposure through ingestion of drinking water with high levels of uranium was studied. Samples were collected at different times from two people living in the same household in southern Finland, whose drinking water is supplied from a private drilled well. The uranium concentration in tap water varied between 9400 and 11 800 µg L-1. During part on the study period the daily intake of uranium from drinking water correlates to this high uranium concentration.
The uranium content in drinking water was determined by quadrupole based inductively coupled plasma mass spectrometry (ICP-QMS) and by alpha spectrometry without and after concentrating the uranium from the water, respectively. Uranium in urine (overnight collection) and in nails was determined by ICP-QMS. The determined uranium concentration in urine was corrected for the matrix effects by use of thallium as an internal standard element and adjusted by creatinine normalization. The nail samples were rinsed to remove external contamination prior to acid digestion and analysis. Hair samples were rinsed to remove external contamination and then analyzed, by ICP-MS after acid digestion. In addition, laser ablation ICP-MS with sector field instrument (LA-ICP-SFMS) was applied for the direct uranium determination on single hairs without sample preparation. Furthermore, isotope ratio measurements were performed in order to explain the origin of uranium contamination.
The results of uranium determination in contaminated water, urine, hair and nail samples were discussed. As a consequence of this study, a water purification system was installed in the family house. Water and hair samples where taken after that for uranium content measurements.
Karpas, Z., Paz-Tal O., Lorber, A., Salonen, L., Komulainen, H., Auvinen, A., Saha, H., and Kurttio, P. Urine, hair and nails as indicators for ingestion of uranium in drinking water. Health Phys. 8,:229-242, 2005