Quinoline-2-aldehyde thiosemicarbazone (QAT) as spectrophotometric reagent for palladium and nickel

Abstract

A procedure is described for the extractive spectrophotometric determination of nickel and palladium with quinoline-2-aldehyde thiosemicarbazone. At pH 7.5 nickel forms a 1:2 complex which is soluble in chloroform and has an absorption maximum at 460 nm. Palladium forms a 1:2 complex with maximum absorbance at 510 nm which can be extracted into MIBK from 1 M HCl. Both complexes are stable and conform to Beer's law. The molar absorptivities for nickel and palladium are 1.58 × 10 4 and 2.6 × 10 3 1.mole −1. cm −1 respectively. The proposed method is suitable for detection and determination of nickel and palladium in the presence of associated metal ions. The results of the analysis of synthetic mixtures and standard samples are reported.