Extractive spectrophotometric determination of vanadium(v) using 3-hydroxy-2-(4-methoxyphenyl)-6-methyl-4H-chromen-4-one

Department of Chemistry, Kurukshetra University, Kurukshetra-136 119, India

Manuscript received 9 December 1998, revised 30 March 1999, accepted 9 April 1999

A simple, sensitive, rapid and selective method for the spectrophotometric determination of vanadium(v) in trace amounts is proposed, using 3-hydroxy-2-(4-methoxyphenyl)-6-methyl-4H-chromen-4-one (HL) as a complexing agent and extracting the coloured 1 : 2 (metal : ligand) complex into 1,2-dichloroethane from 0.1 M CH₃COOH solution. It obeys Beer's law in the concentration range 0.23-2.45 pg mol^-1 V" having molar absorptivity and Sandell's sensitivity of 2.54 x 10⁴ dm³ mol^-1 cm^-1 and 0.00198 fig cm^-2 at 400 nm. The method has been applied satisfactorily to the analysis of various synthetic and technical samples.