EXTRACTION AND SPECTROPHOTOMETRIC DETERMINATION OF MOLYBDENUM(V) USING N-1-HYDROXY-N-1,N-2-DIPHENYLBENZAMIDINE AND THIOCYANATE

Molybdenum(V) has been found to react with thiocyanate and N-1-hydroxy -N-1,N-2-diphenylbenzamidine (HDPBA) to form a 1:3:1(Mo:SCN- :HDPBA) c omplex with a molar absorptivity of 13100 M(-1) cm(-1) at 470 nm. The complex is quantitatively extractable into 2.5% (v/v) amyl alcohol in benzene from 4-6 M hydrochloric acid solutions and the system obeyed B eer's law in the concentration range of 0.5-9.6 mu g mL(-1) of Mo. Opt imum conditions for the extraction and determination of molybdenum hav e been established and a precise, sensitive and highly selective metho d has been developed for the determination of molybdenum(V) by solvent extraction and spectrophotometry. The method has been successfully ap plied to the determination of molybdenum in standard steels and synthe tic matrices.