Determination of uranium isotopes in food and environmental samples by different techniques: a comparison

The uranium concentration in 59 samples of bottled and tap water, mainly from northern Italy, was measured by different techniques. Results obtained by inductively coupled plasma mass spectrometry (ICP-MS), semiconductor alpha spectrometry and low level liquid scintillation counting with alpha/beta discrimination (LSC) have been compared. High resolution gamma spectrometry and semiconductor alpha spectrometry have been used to analyse uranium in a variety of organic and inorganic samples. Isotopic secular equilibrium in the 238U series may be lacking or hidden by auto-absorption phenomena, so caution should be used in evaluating gamma spectrometry data. Alpha spectrometry has also been used to ascertain the possible pollution from depleted uranium in the environment.