Accession Number : AD0619833

Title :   RARE EARTH CHROMATOGRAPHY USING BIS-(2-ETHYLHEXYL) ORTHOPHOSPHORIC ACID,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF GEOLOGY AND GEOPHYSICS

Personal Author(s) : Winchester,John W.

Report Date : 10 AUG 1962

Pagination or Media Count : 5

Abstract : Shart separations of microgram amounts of the lanthanide elements as trivalent ions in aqueous hydrochloric acid solution are made chromatographically using a column of diatomaceous silica made hydrophobic with dichlorodimethylsilane vapors and coated with high purity bis-(2-ethylhexyl) orthophosphoric acid (DEP). Separation factors averaging 2.5 for adjacent rare earths are observed, as in solvent extraction using DEP, such that the higher atomic number elements are more tightly held by the column. The kinetics of the sorption-desorption process appear to be very fast, but elutions at 70C appear to be somewhat sharper than at 25C, especially at high flow rates and high loading. A heated column 5 cm long and 2 cu cm total volume (70% void space) has been used to separate 15 micrograms of mixed lanthanides from each other in 3 h using a stepwide gradient from 0.14 to 3.8 N HC1. La is eluted first, and Y is eluted together with Er. (Author)

Descriptors :   (*RARE EARTH ELEMENTS, CHROMATOGRAPHIC ANALYSIS), (*CHROMATOGRAPHIC ANALYSIS, RARE EARTH ELEMENTS), (*ORGANIC PHOSPHORUS COMPOUNDS, COMPLEX COMPOUNDS), SEPARATION, SORPTION, REACTION KINETICS, SILANES, PHOSPHORIC ACIDS

Distribution Statement : APPROVED FOR PUBLIC RELEASE