Solid-Phase Extraction of Gallium(III) with Hydrophobic 8-Quinolinol Derivatives-impregnated Resin from Aqueous Acidic and Alkaline Solutions

Solid-phase extraction (SPE) of gallium(III) with hydrophobic 8-quinolinol derivatives (HQs)-impregnated resin from aqueous acidic and alkaline solutions has been investigated. The HQs used were 7-(4-ethyl-1-methyloctyl)-8-quinolinol (HEMOQ), 5-octyloxymethyl-8-quinolinol (HO8Q), 2-methyl-5-octyloxymethyl-8-quinolinol (HMO8Q), 5-dioctylamino-methyl-8-quinolinol (HN8Q), 7-bromo-5-octyloxymethyl-8-quinolinol (HBrO8Q), and 5-(2-ethylhexyloxymethyl)-8-quinolinol (HOEHQ). Various factors affecting the SPE, such as the substituents of the HQs, HC1 and NaOH concentrations in the aqueous phase, the HQ concentration in the resin, and the equilibration time were clarified. The extractability for gallium(III) from the aqueous solution became higher in the following order: HBrO8Q < HEMOQ < HO8Q < HN8Q < HMOsQ at 3 mol 1-1H HCl; HMOgQ < H08Q < HOEHQ < HEMOQ < HN8Q < HBrO8Q at pH 0.4; HM08Q < H08Q = HOEHQ < HN8Q < HEMOQ at 3 mol H NaOH.