SPECTROPHOTOMETRIC DETERMINATION OF MICROAMOUNTS OF YTTRIUM WITH 1-AMINO-4-HYDROXYANTHRAQUINONE

1-amino-4-hydroxyanthraquinone (AMHA) is proposed as a spectrophotomet ric reagent for the determination of yttrium. The solution equilibria of AMHA complexes with Y(III) have been studied spectrophotometrically in 50% (v/v) ethanol at 25 degrees C and an ionic strength of I = 0.1 mol . dm(-3) (NaClO4). The complexation reactions were investigated a nd characterized using graphical logarithmic analysis of the absorbanc e graphs. The composition, molar absorptivities, and stability constan ts of the chelates of AMHA with Y(III) have been determined spectropho tometrically. A simple, rapid, selective, and sensitive method for the spectrophotometric determination of microamounts of Y(III) is develop ed based on the formation of the violet YLH(+) complex with lambda(max ) = 580 nm at pH 6.2(epsilon = 0.98 x 10(4) l . mol(-1). cm(-1)). Inte rferences and their elimination have been studied. Many foreign ions a re tolerated in considerable amounts; 45-60 fold amounts of rare earth s do not interfere with the determination of yttrium. In the determina tion of yttrium in synthetic polymetallic samples the relative error a nd relative standard deviation of the method were found to be better t han 1 and 0.5%, respectively.