Development of an analytical technique for the determination of uranium, thorium and rare earth in Thai monazite by neutron activation analysis

The aim of this research is to develop the analytical technique for the determination of uranium, thorium, yttrium, dysprosium, neodymium, praseodymium, lanthanum, samarium, gadolinium, holmium, cerium, ytterbium, terbium and europium in monazite by neutron activation analysis. Uranium and thorium in monazite were first determined. Then another portion of monazite was digested with concentrated perchloric acid in order to separate thorium and mix rare earth. From the precipitate obtained, thorium was separated. Only mix rare earth were left for quantitative analysis of each individual element by neutron activation. By this method, quantitative analysis of rare earth was not interfered by uranium and thorium due to removal of uranium and thorium at the beginning