Spectrophotometric determination of vanadium(V) in minerals, steels, soil and biological samples using phenothiazine derivatives

Two simple, rapid and sensitive spectrophotometric methods have been propos ed for the determination of vanadium(V) using butaperazine dimaleate (BPD) and propionyl promazine phosphate (PPP). These methods are based on the for mation of red-colored radical cations on reaction with vanadium(V) in phosp horic acid medium, with their absorbance maxima at 513 nm. Beer's law is va lid over the concentration range of 0.25 - 5.0 mug ml(-1) and 0.2 - 4.0 mug ml(-1), with Sandell's sensitivity values of 6.1 ng cm(-2) and 6.0 ng cm(- 2) for BPD and PPP respectively. ne proposed methods have been successfully applied to the analysis of vanadium steels, minerals, biological samples a nd soil samples.