Measurement of uranium and its isotopes at trace levels in environmental samples using mass spectrometry

Abstract

: Actinides have widely entered the environment as a result of nuclear accidents and atmospheric weapon testing. These radionuclides, especially uranium, are outstanding radioactive pollutants, due to their high radiotoxicity and long half-lives. In addition to this, since depleted uranium (DU) has been used in the Balkan conflict in 1999, there has been a concern about the possible consequences of its use for the people and environment. Therefore, accurate, precise and simple determination methods are necessary in order to evaluate the human dose and the concentration and effects of these nuclides in the environment. The principal isotopes of uranium e.g. 235 U and 238 U are of primordial origin and 234 U present in radioactive equilibrium with 238 U. 236 U occurs in nature at ultra trace concentrations with a 236 U : 238 U atom ratio of 10 -14 . Concentrations of uranium in soil samples were determined using inductively coupled plasma mass spectrometry (ICP-MS) and isotope ratios of uranium were measured using a thermal ionisation mass spectrometer. Radioactive dis-equilibrium of 234 U/ 238 U, depletion of 235 U/ 238 U and significant evidence of 236 U/ 238 U were noticed in soil samples.

Measurement of 238 U/ 235 U ratio in black spruce seedlings to fingerprint the source of uranium taken up by black spruce trees as a biogeochemical sampling medium

“…The magnitude of the deviation was related to the concentration of DU applied to the media (Fig. 3) and corroborated findings by Westphal et al (2004) and Sahoo (2009). Precision for NAA determinations of 238 U/ 235 U ratio in the DU-dosed substrates is markedly high and ranged from 7 to 14% whereas the ICP-QMS determinations typically ranged from 0.06 to 2.0%.…”

Uranium Sources, Uptake, Translocation in the soil-plant System and Its Toxicity in Plants and Humans: A Critical Review

“…With ever exploding global population increase, this anthropogenic content of U will increase in the future due to higher demand for minerals, electricity, and food 8,[26][27][28] . Uranium concentration and radiation strength in the soil of different countries varies highly, as shown in Table 1 [29][30][31] . Highest concentration and radiation of Uranium in the soil was found in Portugal (25.10 mg/kg and 311.24 Bq/kg respectively).…”

“…1. Uranium sources in the ecosystem distribution and sources of Uranium in soilUranium concentration and radiation strength in the soil of different countries varies highly, as shown in Table1[29][30][31] . Highest concentration and radiation of Uranium in the soil was found in Portugal (25.10 mg/kg and 311.24 Bq/kg respectively).…”

Determination of Uranium Contents in Soil Samples in AL-Hamdaniya Region Using Solid State Nuclear Track Detector CR-39

“…The concentration of uranium in soil varies widely. Depending on the geological location, its concentration in the surface soil vary from 0.1 mg.Kg -1 to 20 mg.Kg -1 with a world average of 2.8 mg. Kg -1 (specific activity 35 Bq/Kg) [8], and the allowed limit 11.7 ppm [10] . CR-39 (The plastic SSNTD) detector was used to find the concentration of uranium in the soil.…”