Measurement of uranium isotopes in environmental samples by ICP-MS

A new method for simultaneous and fast determination of uranium isotopes (²³⁴U, ²³⁵U, and ²³⁸U) in environmental samples by ICP-MS has been developed. In this research, we employed an extraction chromatography for separation and purification of uranium from water, soil, and sediment samples. Low detection limits of this method are ultimately achieved. They are 0.7 m Bq/g for ²³⁴U, 0.002 m Bq/g for ²³⁵U, and 0.04 m Bq/g for ²³⁸U in soil and sediment samples. In water samples they are 0.000 1 Bq/L, 6 × 10^-7 Bq/L, and 1 × 10^-5 Bq/L respectively. This method is validated by analyzing seawater reference material IAEA-443, soil reference material IAEA-447, and sediment reference material NIST-4357 with average recovery ratios of 84.2%, 93.4%, and 90.6% respectively. All results obtained correspond well to those certified values and corroborate the validity and veracity of this method. (authors)