Sensitive derivative spectrophotometric determination of gold(III) using 3,5-dimethoxy-4-hydroxybenzaldehyde isonicotinoyl hydrazone (DMHBIH) in presence of micellar medium

A simple and sensitive spectrophotometric method ha s been developed for the determination of gold(III) using the newly synthesized reagent 3,5-dimethoxy-4 -hydroxybenzaldehyde isonicotinoyl hydrazone (DMHBIH) in a neutral surfactant of Triton X-100 (5 %) (micellar medium). Gold(III) forms an orange coloured water soluble complex with the reagent in acidic medium pH 4.0. The molar absorptivity and Sandell’s sensitivity of the coloured species are 1 .14×10 l mol cm and 0.004587 μg/cm, respectively. Beer’s law is obeyed in the range 0.197-1.97 μg/ml of Au(III) at λmax at 386 nm. The developed derivative spectrophotometric method was satisfactorily applie d for the determination of gold(III) in synthetic mixtures, certified reference materials, water samples and ph armaceutical samples.