DETERMINATION OF ~(234)U/~(238)U RATIO: COMPARISON OF MULTI-COLLECTOR ICPMS AND ICP-QMS FOR WATER, HAIR AND NAILS SAMPLES, AND COMPARISON WITH ALPHA-SPECTROMETRY FOR WATER SAMPLES

摘要

The ~(234)U/~(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 4percent for water samples containing 1 (mu)g 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 (mu)g l~(-1) of uranium and measurement time was approx1 min, while alpha-spectrometry involved pre-concentration and separation of the uranium and counting times of 1000 min.