Solvent extraction and spectrophotometric determination of vanadium(V) with 2,2′-dipyridyl-2-quinolylhydrazone

Abstract

2,2′-Dipyridyl-2-quinolylhydrazone (DPQH) has been used for the extractive spectrophotometric determination of vanadium(V) after the cation-exchange separation of this ion from metal ions. Vanadium(V) reacts with DPQH in weakly acidic solution to form a 1 : 1 metal to ligand complex that is extractable into many organic solvents. The species when extracted with chloroform has an absorption maximum at 572 nm and obeyes Beer's law over the range up to 1.5 µg ml^–1 of vanadium. The method has been satisfactorily applied to the determination of vanadium in three standard alloy steel samples. A possible structure for the extracted species is postulated.