nickel and lead samples.

Simple, sensitive and accurate spectrophotometric method  has been developed for sequential separation of Co II,NiII and PbII with α-oximinoacetoacetaanilidebenzoylhydrazone(HINABH). HINABH forms Yellowish brown  complex with Co II and yellow colored complexes with NiII and PbII.CoII-HINABH complex was extracted in to n-butanol  in the pH range 6.0-7.0 at λ max 425 nm., whereas Ni II and PbII complexes were extracted into isoamylalcohol quantitatively in the pH range 8.5-9.5 at λ max 420nm and 410 nm respectively. HINABH complexes of Co II,NiII and PbII obeyed Beer’s law in the range of 0.2-5.0 ppm,1-14 ppm and 2-16 ppm respectively. The method had been successfully employed for the determination of Co II,NiII and PbII in the synthetic mixtures and alloys.