Spectrophotometric determination of molybdenum based on charge transfer complex in PVA medium

A very simple, selective and sensitive method was developed for the spectrophotometric determination of Mo in the presence of W. The method was based on the formation of color charge transfer complex, molybdotungstophosphate-3,3′,5,5′-tetramethylbezidine anion, which was solubilized and stabilized in PVA medium. Following the recommended procedure, molybdenum could be determined in the linear range of 0.04–2.5 μg ml−1 and the molar absorptivity was 1.47×104 l mol−1 cm−1 at 660 nm. The proposed method had been applied to the determination of trace molybdenum in tungsten ore with satisfactory results.