Solvent extraction and determination of scandium(III) with Cyanex272 as an extractant
A novel method for the solvent extraction separation of scandium(III) at pH 5.0 using 5 × 10-4 M Cyanex272 has been developed. Scandium(III) has been stripped from the organic phase with 1.0 M HNO3 and determined spectrophotometrically as its complex with Arsenazo(III) at 675 nm. The method developed has been applied for selective separation of scandium(III) from some closely associated elements, viz., La(III), Y(III), Ce(IV), Zr(IV), Dy(III), Nd(III), Pr(III), Yb(III), etc. in their binary mixtures. The method permits mutual separation of scandium(III)-yttrium(III)-lanthanum(III) and scandium(III)-yttrium(III)-cerium(IV) and for recovery of scandium(III) from USGS standard soil sample GXR-2, Japanese stream sediment sample Jsd-3 and ashes from Hutti gold mines in Karnataka. The method presented is simple, rapid and selective for isolation of scandium(III) from complex mixtures. The method developed is reproducible with a relative standard deviation of 0.4%.