- L Fernandez: Department of Analytical Chemistry (Dr Carlos B. Marone) Faculty of Chemistry, Biochemistry and Pharmacy, University of San Luis, Argentina.
The operating conditions for the absorptiometric determination of Yb(III) with the reagent 2-(3,5-dichloro-2-pyridylazo)-5-dimethylaminophenol (3,5-diClDMPAP) by a liquid-liquid extraction technique are presented. The complex yields a molar absorptivity of 1.54 x 10(5)l.mole(-1).cm(-1) (lambda(max) = 588 nm) and an optimum concentration range of 0.025-1.360n mg/l., at pH = 10. The method developed has been applied to the determination of Yb(III) in synthetic and concrete mixtures.