Direct, 2nd and 3rd Derivative Spectrophotometric Determination of Indium (III) Using 2-Hydroxy-1-Naphthaldehyde-P-Hydroxybenzoichydrazone in CTAB Micellar Medium

A new chromophore, 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) is used first time for the direct and derivative spectrophotometric investigations of indium (III). The metal ion reacts with the reagent in aqueous dimethyl formamide (DMF) in wide pH range forming greenish yellow coloured 1:2 (M: L) complex with max at 450 nm. The colour intensity further increases in the presence of cityl tri methyl ammonium bromide (CTAB) micellar medium at room temperature. Obeying of Beer’s law is taken place in the wide range 0.057-2.869 μg mL-1 of In (III). The molar absorptivity, Sandell’s sensitivity, detection limit, determination limit and relative standard deviation are calculated as 8.8 x 104 L mol-1cm-1, 0.0013 μg cm-2, 0.004 μg mL-1, 0.012 μg mL-1 and 1.66 % respectively. The second and third order derivative spectrophotometric methods are also developed for the determination of indium (III) which showed greater sensitivity and selectivity. The proposed direct and derivative methods are applied for the determination of indium in zinc effluents and alloys, in synthetic mixtures and in reference materials.