Preconcentration neutron activation analysis of lanthanides by cloud point extraction using PAN

Summary Methods for the simultaneous preconcentration of lanthanides by cloud point extraction and their determination using neutron activation analysis have been developed. The preconcentration method involves the use of a nonionic surfactant and a chelating agent. A fairly small volume of surfactant-rich phase was obtained under optimized experimental conditions, leading to detection limits between 0.3 and 3.0 ng ^. g^-1. Critical parameters that influence extraction efficiency were solution pH and concentration of chelating agent, and to a lesser extent, ionic strength and temperature. Most of the chelates were quantitatively extracted (>90%) at high pH values. Selective separation can be achieved by varying some of the experimental conditions.