Determination of 234U/238U ratio: comparison of multi-collector ICPMS and ICP-QMS for water, hair and nails samples, and comparison with alpha-spectrometry for water samples

The 23 4U/ 238 U ratio in water, hair and nails samples was determined by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) and inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) and by alpha-spectrometry for the water samples only. A correlation of 0.99 was found between the two ICPMS methods and of 0.98 with alpha-spectrometry. The range of activity ratios was between 0.9 and 2.6 according to the MC-ICPMS measurements. The reproducibility of both ICPMS techniques was better than 4% for water samples containing 1 μg l -1 of uranium and a 234 U/ 238 U atom ratio of 54.9 x 10 -6 . Sample preparation for the ICPMS consisted of dilution of water samples containing >10 μg l -1 of uranium and measurement time was ∼1 min, while alpha-spectrometry involved pre-concentration and separation of the uranium and counting times of 1000 min.