Spectrophotometric determination of zinc with 1-[di(2-pyridyl)methylene]-5-salicylidenethiocarbonohydrazide

Abstract

The synthesis, physico-chemical properties and analytical applications of 1-[di(2-pyridyl) methylene]-5-salicylidenethiocarbonohydrazide (DPST) are described. The reaction between zinc and DPST has been studied spectrophotometrically and a method for the determination of this ion is proposed based on the yellow chelate formed. The spectrophotometric procedure is sensitive, with a molar absorptivity at 417 nm of 60 500 | mol^–1 cm^–1(pH 5.6), in a solution containing 30%V/V of dimethylformamide. The conditions for optimum colour development and the nature of the reaction and interferences were studied. The method was applied to the determination of zinc in potable waters and pharmaceutical preparations.