Solvent Extraction of Seven Trivalent Metal Ions in Aqueous Perchiorate Solutions with Trioctylphosphine Oxide in Hexane and Rapid Extraction of Chromium(III)

• Published in: Analytical Sciences Vol. 12; no. 3; pp. 405 - 410
• Main Authors: YAMADA, Meri, KUSAKABE, Satoshi, PREKOPOVA, Jana, SEKINE, Tatsuya
• Format: Journal Article
• Language: English
• Published: Tokyo The Japan Society for Analytical Chemistry 10.06.1996; Japan Science and Technology Agency
• Subjects: Chromium; chromium(III); Europium; europium(III); Gallium; gallium(III); indium(III); Lanthanum; lanthanum(1II); Metal ions; perchlorate; Scandium; scandium(III); Sodium chloride; Solvent extraction; Solvents; trioctylphosphine oxide; Yttrium; yttrium(III)
• ISSN: 0910-6340; 1348-2246
• DOI: 10.2116/analsci.12.405

Solvent extraction of scandium(III), yttrium(III), lanthanum(III), europium(III), gallium(III), indium(III), and chromium(III) in weakly acidified 1mol dm-3 NaClO4 solutions with trioctylphosphine oxide (TOPO) in hexane was studied. The extraction equilibrium was established by the two phase agitation for within 3min and the extracted species except chromium(III) were found to be M(TOPO)43+(ClO4-)3. The extraction of chromium(III) was also achieved by the two phase agitation for only a short time but, from the dependence of the extraction on the TOPO concentration, the extracted species was assumed to be Cr(TOPO)63+(ClO4-)3. Since the inert Cr(H2O)63+ was so rapidly extracted and the solvation number was higher than that of the other metal ions, the TOPO molecules were assumed to combine with the hydrating water molecules by hydrogen bonds which can be formed in a short time even when the metal ion was inert. The chromium(III) was also extracted rapidly from 1mol dm-3 NaSCN, NaNO3, NaBr, and NaCl solutions with TOPO in hexane and the extraction was better from NaSCN solution than from NaClO4 solution but it was not effective from the solutions of other salts.