High Precision Determination of Microgram Quantities of Rare Earth Metals By X-Ray Emission Spectrography of Ion Exchange Paper Disk

Abstract

Rare earth metals, in the range of 0 to 250 micrograms, have been extracted quantitatively from perchloric, nitric or hydrochloric acid solutions by strong acid ion exchange paper disks in the sodium ion form. After the exchange is completed, the ion exchange paper disk is placed in a rotating sample holder and the amount of rare earth metals exchanged is determined by x-ray emission spectrography. At the 10 microgram level, the accuracy has a mean error of 2% with a precision of 1.5% relative standard deviation. The procedure has been applied to Sc⁺³, Y⁺³, Ce⁺⁴, Pr⁺³, Nd⁺³, Sm⁺³, Eu⁺³, Gd⁺³, Tb⁺³, Dy⁺³, Ho⁺³, Er⁺³, Tm⁺³, Yb⁺³ and Lu⁺³.