A SELECTIVE AND RAPID MICRODETERMINATION OF MOLYBDENUM(VI) USING 2', 4'-DIHYDROXYACETOPHENONE BENZOYLHYDRAZONE AS A NEW REAGENT

A simple, rapid and selective spectrophotometric method for the microd etermination of molybdenum(VI) using 2',4'-dihydroxyacetophenone benzo ylhydrazone (DHABH) as a new reagent has been developed. The greenish- yellow Mo(VI)-DHABH complex with lambda(max) at 402 nm, is extractable into benzene from 0.01-0.10 M HCl medium containing 0.5-1.4 ml of 0.2 % solution of the reagent in acetone. The 1:1 species in benzene obeys Beer's law in the range 0-17.5 mug Mo ml-1 and is stable for more tha n one week. The molar absorptivity, Sandell's sensitivity and standard deviation are 0.940 x 10(4) l mol-1 cm-1, 0.0102 mug Mo CM-2 and +/-0 .0055 respectively. The method has been used for the determination of molybdenum(VI) in various alloy steels and a wide variety of synthetic samples with satisfactory results.