Direct and derivative spectrophotometric determination of gold (iii) using 3,5-dimethoxy-4-hydroxybenzaldehyde benzoylhydrazone(dmbbh) in presence of micellar medium.

A simple and sensitive spectrophotometric method has been developed for the determination of Gold (III) using 3,5-Dimethoxy-4-hydroxy benzaldehyde benzoylhydrazone (DMBBH) in a neutral surfactant of Triton X-100(5%) (micellar medium). Gold (III) forms an wine red coloured water soluble complex with the reagent in acidic medium pH 5.0. The molar absorptivity and Sandell’s sensitivity of coloured species are 2.32 x 104 L.mol-1 cm-1 and 0.00862 mg/cm2 respectively. Beer’s law is obeyed in the range 0.4925-5.91 mg/ml of Au(III) at lmax at 380 nm. The developed derivative spectrophotometric method was employed for the determination of gold (III). This method has been satisfactorily applied for the determination of gold (III) in water samples and pharmaceutical samples.