A RAPID SPECTROPHOTOMETRIC DETERMINATION OF MOLYBDENUM(VI) USING 2'-HYDROXYACETOPHENONE BENZOYLHYDRAZONE

2'-Hydroxyacetophenone benzoylhydrazone (HABH) has been used for the first time as an analytical reagent for determination of molybdenum spectrophotometrically. Molybdenum (VI) in presence of large number of cations, anions, and complexing agents except oxalate and borate, forms a yellow complex with HABH extractable into carbon tetrachloride from weakly acidic solution. As many as 31 cations, 15 anions, and complexing agents were studied. The absorbance of the complex was measured at 390 nm. The color was stable for more than 18 h. The system conformed to Beer's law over the concentration range of 1.28 to 13.8 mug of molybdenum per cm3. The procedure is simple, selective, reproducible and takes <10 min in a single determination of molybdenum in large number of synthetic samples.