Selective spectrophotometric determination of trace amounts of molybdenum with 2,2′-dihydroxybenzophenone thiosemicarbazone

Abstract

2,2′-Dihydroxybenzophenone thiosemicarbazone reacts with molybdenum in solutions in mineral acids in the presence of tin(II) chloride to produce a red 1 : 1 complex (λ_max.= 500 nm, ε= 3.3 × 10³ l mol^–1 cm^–1). This complex is used for the spectrophotometric determination of trace amounts of molybdenum. The interferences of many metallic ions have been examined and a procedure for the determination of molybdenum in synthetic mixtures is proposed. Interfering metals can be removed by a preliminary extraction with dithizone.