On the Determination of 228Ra, 210Po, 234U and 238U in Mineral Waters

The importance of the determination of uranium, radium and polonium isotopes in drinking water is outlined, taking into account European legislation. The results of a literature study of radiochemical and measurement techniques suitable for the determination of these radionuclides in water are summarised. The method developed for the determination of 228Ra consisting of radium preconcentration, radiochemical separation of radium and subsequent determination of the daughter 228Ac with liquid scintillation counting is described. Two novel methods for the sequential radiochemical separation of polonium and uranium from water samples were developed and are described in detail. The 228Ra activity concentration was determined in two mineral waters and is compared with the results of an alternative method, based on the ingrowth of 228Th and alpha-particle spectrometry. The two novel methods for polonium and uranium were applied to three different mineral waters, and the activity concentrations of 210Po, 234U and 238U determined with alpha-particle spectrometry are compared among each other and with reference values determined for these waters with standard methods.JRC.D.4-Isotope measurement

Evaluation of EC Comparison on the Determination of 226Ra, 228Ra, 234U and 238U in Mineral Waters

This report describes all details of the comparison for the determination of 226Ra, 228Ra, 234U and 238U in mineral waters among 45 European laboratories monitoring radioactivity in food and the environment. Three commercially available mineral waters were provided as comparison samples. Reference values of the four radionuclides under study in this comparison were determined in collaborative work of IRMM and the Bundesamt für Strahlenschutz (BfS), using tracer techniques and standardised radionuclide solutions. The reference values are thus traceable to the SI units. The sample preparation and measurement processes applied in the participating laboratories are described and the results of the comparison are presented and discussed in detail. Whereas, in general, the measurement results for the uranium isotopes show a relatively favourable agreement with the reference value, the results of this comparison point at severe problems of 226Ra and 228Ra determination in about one fourth and more than one third of the laboratories, respectively. For radium, 19 results corresponding to 14 % of all are even off by a factor of two or more. By comparison, for uranium, this number amounts to 6 % (9 results out of 150). Nevertheless, also for the determination of uranium, 14 % to 23 % of the laboratories report results not compliant with the En evaluation criterion. The corresponding participants are urgently requested to investigate and revise their analytical methods.JRC.D.4-Nuclear physic

Uncertainty Budget for 226 Ra Activity Concentration in Water by Alpha Spectrometry

Abstract Alpha-particle spectrometry is the most frequently used technique for the activity determination of alpha emitters, such as radium, uranium, plutonium, americium and thorium in environmental samples. In this paper an extensive uncertainty budget is presented for a typical alpha-particle spectrometry measurement of the 226 Ra activity concentration in drinking water. The most influential parameters contributing to the uncertainty are investigated. The set-up used is a common alpha-spectrometry system for environmental samples using PIPS detectors. In particular, the influence of geometrical parameters as well as the activity distribution in the measured sources on the solid angle is scrutinised

Development of the Procedure for Simultaneous Determination of Vanadium, Uranium and Manganese in Biological Materials Using RNAA

Radiochemical neutron activation analysis (RNAA) for simultaneous determination of V, U and Mn at trace levels in biological materials is described. This method is based on short irradiation of the sample together with standards and sequential separations of the induced nuclides based on selective solvent extractions. The chemical yield of the radiochemical procedure for each radionuclide was determined. The method was tested by the analysis of available reference materials.JRC.D.4-Isotope measurement