Spectrophotometric determination of microamounts of scandium with o-chlorophenylfluorone and cetyltrimethylammonium bromide

The reaction of scandium(III) with o-chlorophenylfluorone (o-ClPF) in the presence of cetyltrimethylammonium bromide (CTMAB) has been studied. In an acetate buffer at pH 4.4, a red-purple complex is obtained, with maximum absorption at 569 nm and a molar absorptivity of 1.31 x 105 l.mole-1.cm-1. The composition of the complex is found to be 1:2:2 Sc-o-ClPF-CTMAB. Beer's law is obeyed over the range 0-12 μg/25 ml scandium. The proposed method has been used for determination of trace scandium in tungsten ores after its prior separation by solvent extraction. (author)