Study of the extraction of vanadium(V)-N-p-octyloxybenzoyl-N-phenylhydroxylamine complexes from sulphuric acid solutions containing chloride, fluoride or thiocyanate

The extraction of vanadium(V)-N-p-octyloxybenzoyl-N-phenylhydroxylamine (OBPHA) complexes from sulphuric acid containing chloride, fluoride or thiocyanate is described. The purple, red and reddish blue complexes extracted, containing chloride, fluoride or thiocyanate, have molar absorptivities of 6.1 x 10(3), 5.08 x 10(3) and 7.9 x 10(3) 1.mole(-1) .cm(-1) with maximum absorption at 540, 490 and 570 nm, respectively. A spectrophotometric determination of vanadium(V) has been based on these results. The composition of the extracted complexes is estimated as V(V): OBPHA:X(-) = 1:2:1 (X(-) = Cl(-), F and SCN(-)).