LIQUID -LIQUID EXTRACTION OF CERIUM (III) SALICYLATE WITH TRIS (2-ETHYLHEXYL) PHOSPHATE AND TRIBUTYLPHOSPHINE OXIDE

Tris (2-ethylhexyl) phosphate (TEHP) and Tributylphosphine oxide (TBPO) are proposed as extractants for the solvent extraction of cerium (III) from salicylate media. A critical study of various experimental parameters such as pH, sodium salicylate concentration, TEHP and TBPO concentration and period of equilibration showed that TBPO is a better extractant, due to its higher basicity. Cerium (III) from organic phase is stripped with distilled water and determined by Arsenazo III. The extraction of cerium (III) with both extractants occurs by solvation mechanism and the extractant dependencies of the extractions suggests that the extracted species are solvated metal salicylate salts, Ce (HSal)3 . 3TEHP and Ce (HSal)3 . 2TBPO respectively. The method permits separation and determination of cerium from binary and synthetic mixtures of commonly associated elements.