SPECTROPHOTOMETRIC DETERMINATION OF SCANDIUM IN ALLOY 01570

The complexation of scandium with chromazurol S and eriochromcyanine R in the presence of cationic polyacrylamide (brand «FO»)with different charge density was investigated by spectrophotometry. The formation of ternary metal-polymeric complexes of organic reagent – polyacrylamide – scandium was established. The composition of ternary metal-polymer complexes determined by the ternary Gibbs-Rosenbaum diagram were 6:3:1 for ECC – FO4650 – Sc, 1:1:1 and 1:3:1 for XAS – FO4400 – Sc. The system of ECC – FO4700 – Sc is proposed as analytical form for spectrophotometric determination of scandium due to high molar absorbtivity for this complex determined from the slope of the calibration graph (7.2·104 mol–1·L·cm–1). The proposed technique allows to determine Sc3+ in the range of concentrations 9 – 90 μg/L. The limit of determination is 5.5 μg/L. The sample of scandium-containing alloy 01570 was analyzed by proposed technique (Sr=0.054). The scandium was preliminarily separated from disturbing components by the precipitation with NaOH. The correctness of the rezults is confirmed by the standard procedure technique.