2, 2′-Diquinolyl-2-quinolylhydrazone as a Highly Sensitive Reagent for the Extractive Spectrophotometric Determination of Cadmium(II)

Abstract

A new, heterocyclic hydrazone ligand, 2, 2′-diquinolyl-2-quinolylhydrazone(DQQH), is synthesized and used for the spectrophotometric determination of traces of cadmium(II). Cadmium(II) is preliminarily extracted as the iodide complex into mesityl oxide from sulfuric acid solution. The cadmium(II) is converted to a strongly colored complex by the subsequent treatment of the extract with a DQQH solution in benzene in the presence of an ammonia-sodium hydroxide solution. The analytical species of interest has an absorption maximum at 552nm and obeys Beer′s law over the range up to 9×10^-6M(mol dm^-3) cadmium in the organic phase. The molar absorptivity is 9.15×10⁴ dm³ mol^-1 cm^-1 at 552nm. The composition of the cadmium(II)-DQQH complex and the effect of foreign ions on the determination of cadmium are also investigated.