Application of laser ablation inductively coupled plasma mass spectrometry for the isotopic analysis of single uranium particles.

The paper describes the application of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for the isotopic analysis of individual uranium-oxide particles. The procedure developed is suitable for the accurate measurement of 234U, 235U, 236U and 238U isotopes in single actinide particles with lateral dimensions down to 10 microm. The 235U/238U isotope ratios can be obtained with a precision of a few percent relative standard deviation using a single collector ICP-MS instrument. The precision could be improved by the use of slow ablation and by taking several LA-ICP-MS replicate spectra on the same particle investigated. For the minor isotopes use of higher mass resolution (R=4000) was necessary in some cases to avoid spectral interferences. The technique developed offers a rapid and accurate possibility for the isotopic composition determination of uranium-containing individual particles in environmental and safeguards samples.