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

Chem. Met. Alloys 4 (2011) 143-151

https://doi.org/10.30970/cma4.0180

G.V.S. VALLINATH, K.B. CHANDRASEKHAR, N. DEVANNA

A simple and sensitive spectrophotometric method has 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 1.14×10⁵ l mol^-1 cm^-1 and 0.004587 μg/cm², respectively. Beer’s law is obeyed in the range 0.197-1.97 μg/ml of Au(III) at l_max at 386 nm. The developed derivative spectrophotometric method was satisfactorily applied for the determination of gold(III) in synthetic mixtures, certified reference materials, water samples and pharmaceutical samples.

Structure of 3,5-Dimethoxy-4-hydroxybenzaldehyde isonicotinoylhydrazone (DMHBIH).

Keywords

Gold(III) / 3,5-dimethoxy-4-hydroxybenzaldehyde isonicotinoylhydrazone (DMHBIH) / Micellar medium / Derivative spectrophotometry