Rare earths in environment and geologic samples determined by neutron activation analysis

Neutron activation analysis allows to determine rare earth elements (REE) with a sensivity much higher than non-nuclear methods. In this work, this technique has been applied to the determination of REE in environmental samples, such as marine suspended particulate matter and sea, lake and river sediments. The importance of lanthanides in the environmental field is due to the fact that some REE, because of their nearly identical physico-chemical behaviour, can simulate the environmental behaviour of actinides, generated by activation or fission processes. Am(III) can be simulated by Eu(III) and Nd(III), that can simulate also Cm(III). As regardes REE in geological studies, their distribution and fractionation in rocks provide information about the genesis and the evolution of the rocks themselves. In this work, some data relevant to Kenya rocks are presented