SPECTROPHOTOMETRIC DETERMINATION OF ZIRCONIUM WITH 5-CHLORO-8-HYDROXY-7-IODOQUINOLINE

Trace amounts of zirconium have been determined spectrophotometrically employing 5-chloro-8-hydroxy-7-iodoquinoline (chloroiodo-oxine) as a complexing agent for the metal ion. Tile coloured complex thus formed on complexation is extractable into chloroform from dilute hydrochlori c acid soluton, exhibiting an absorption maximum at 410-415 nm. A larg e number of metal ions, among others Co(II), NI(II), Mn(II), As(lII), Bi(III), Ir(III), Au(III), Ru(lII), Pt(IV), Th(IV), U(VI), and Os(VIII ), do not interfere. Molar absorptivity and Sandell sensitivity of the method are 1.57 x 10(4) l mol(-1) cm(-1) and 5.3 x 10(-3) mu g cm(-2) , respectively, with a Beer's law range of 0-6 mu g ml(-1) Zr Using 2 mu g ml(-1) of Zr the relative standard deviation of the procedure was found to be 1.3%.