Derivative spectrophotometric determination of vanadium in alloys and environmental samples after adsorptive extraction of its 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol chelate onto microcrystalline benzophenone

摘要

Benzophenone has been used as a nextractant for the preconcentration of vanadium as vanadium-2-(5-bromo-2-pyridylazo)-5-diehthylaminophenol(5-Br-PADAP) complex from a fairly large volume (400 ml) of its aqueous sample in weaakly acidic condition (pH 3.5-5.0). The solid mass is dissolved in 5 ml of acetonitrile and quantified by second-deriative spectrophotometry (peak-to-peak method).