Controlled-potential coulometric determination of the rare earths in acetonitrile

Controlled-potential coulometry was examined as a means of determining the lanthanide series of rare-earth elements. It was found possible to reduce quantitatively, europium, ytterbium, and samarium, from the tri- to the di-positive state in acetonitrile solutions of the perchlorates, using tetraethylammonium perchlorate as the supporting electrolyte salt. The method suffers from the lack of a convenient method of sample preparation. The attempted determination of neodymium failed.