Rapid direct spectrophotometric determination of zirconium(IV) in alloys with 2,2/,3,4-tetrahydroxy-3/-sulpho-5/-carboxyazobenzene reagent

Abstract

In this study, 2, 2', 3, 4-tetrahydroxy-3'-sulpho-5'-carboxyazobenzene (tetrahydroxyazon SC) has been synthesized for the first time and used for direct spectrophotometric determination of zirconium(IV). Tetrahydroxyazon SC in a 5.0 M acidic medium (up to pH 6) with zirconium(IV) gave a red complex (Zr-tetrahydroxyazon SC), which has maximum absorption at 495 nm (molar absorptivity, 4.9×104 l mol-1 cm-1) in a 2 M HCl medium. Stoichiometric composition of complex is 1:2 in aqueous solution. Absorbance of complex obeys Beer's law under optimum conditions [zirconium(IV) conc., 0.10-2.80 mg ml-1]. Proposed method is highly sensitive, selective, rapid and simple. It has been applied to direct determination of zirconium(IV) in aluminum, zinc and copper based standard certified alloys without any separating procedure.