[Spectrophotometric determination of vanadium(V) through the formation of a tungstovanadophosphate-TMBPS charge transfer complex].

A new spectrophotometric method was developed for the determination of vanadium(V). The method was based on the formation of tungstovanadophosphate-3,3',5,5'-tetramethylbenzidine-N-propanesulfonic (TMBPS) charge transfer complex. The spectrophotometric measurements were directly carried out at 450 nm and the apparent molar absorptivity was 2.