Simultaneous spectrophotometric determination of molybdenum(VI) and titanium(IV) using 2,4-dihydroxybenzaldehyde isonicotinoyl hydrazone

Determination of molybdenum(VI) by direct spectrophotometry and simultaneous determination of molybdenum(VI) and titanium(IV) are reported. Molybdenum(VI) gives a golden yellow colour with 2,4-dihydroxybenzaldehyde isonicotinoyl hydrazone with a 1:2 metal-reagent stoichiometry at pH 1.5. The complex shows an absorption maximum at 445 nm with molar absorptivity and Sandell's sensitivity of 1.02x10(4) l mol(-1) cm(-1) and 0.0094 mu g cm(-2) respectively. Beer's law is obeyed in the range 0.3-6.0 mu g ml(-1) of Mo(VI). Titanium(IV) and molybdenum(VI) have been determined simultaneously by measuring the absorbance of the solution mixture at 445 nm and 560 nm respectively. The method has been applied for the simultaneous determination of molybdenum(VI) and titanium(IV) in steel samples.