title: Spectrophotometric determination of zirconium with 2-(1-hydroxy-4,6-dinitro-2-phenylazo)-1,8-dihydroxynaphthalene-3,6-disulphonate (picramine ca) as chromogenic reagent.
abstract: The title compound has been used as a selective reagent for the micro-determination of zirconium in acidic medium (0.5MHCl) and found to be better than Picramine R. Spectrophotometric studies show the formation of a 2:1 (ligand:Zr) water-soluble complex and the reaction is suitable for photometric determination of 0.4-2.8 ppm of zirconium. The colour takes about 90 min to develop fully and is stable for about 20 hr. The molar absorptivity of the complex is 2.4 x 10(4) and the equilibrium constant is of the order of 10(10). The interference due to a number of ions has been studied.
authors.affiliation: Chemical Laboratories, University of Rajasthan, Jaipur, India.
authors.forename: S S
authors.initials: SS
authors.lastname: Goyal
authors.forename: J P
authors.initials: JP
authors.lastname: Tandon