Uranium concentration in water samples for measurement by alpha spectrometry

The uranium quantification in drinking water samples often presents a challenge, since the amount of uranium in this matrix is usually low; in addition a radiochemical process of the element has to be performed to proceed with its analysis by alpha spectrometry. The uranium quantification by this method includes four stages: 1. Co-precipitation of the interest element in the water sample, whose purpose is to make a preliminary separation of the uranium. 2. Chemical separation of uranium, in which uranium radioisotopes isolated from the other elements that the sample may contain are obtained. 3. Preparation of the alpha uranium source by electro-deposition on stainless steel plates and 4. The radiation source count was performed using an alpha spectrometry system. In the present work the qualitative comparison of two procedures of chemical separation of uranium is carried out, the first one is based on the principle of ion exchange using a synthetic resin and the second one using liquid-liquid extraction with tri-n-butyl phosphate (Tbp) as an extractant solvent, stages 1, 3 and 4 in both procedures were the same. The comparison of these two separation methods is made in order to select the one with which the best possible alpha spectrum is obtained since it will subsequently be used to perform the quantitative determination of the radioactive imbalance between the uranium radioisotopes contained in groundwater samples mainly in the relationship ²³⁴U/²³⁸U. (Author)