Determination of uranium in Egyptian graniteic ore by gamma, alpha, and mass spectrometry

Abstract

Three methods were employed for the determination of uranium in granitic ore rock samples. Gamma spectrometry is a non-destructive technique while alpha spectrometry and inductively coupled plasma–mass spectrometry (ICP-MS) are destructive methods needing application of radiochemical separation before uranium measurement. In gamma spectrometry, the activity concentration of uranium is measured via its daughter (234mPa) in the decay series, while in alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS), the activity concentration of uranium is measured directly. The activity concentrations of uranium in the samples by gamma spectrometry were between 36.7 ± 0.5 and 239 ± 2.3 Bq g−1. The activity concentrations of uranium by alpha spectrometry and ICP-MS were from 28.7 ± 1 to 145 ± 1 Bq g−1 and 34.3 ± 1.4 to 155.9 ± 1.6 Bq g−1, respectively. The ICP-MS and alpha spectrometry methods provided reliable results. The uranium concentrations obtained by gamma spectrometry were, however, systematically too high.