Differential pulse polarography determination of indium after column preconcentration with [1-(2-pyridylazo)-2-naphthol]-naphthalene adsorbent or its complex on microcrystalline naphthalene.
A highly selective, sensitive and economical differential pulse polarographic method has been developed for the determination of trace amount of indium in various samples after adsorption of its 1-(2-pyridylazo)-2-naphthol on naphthalene in the pH range of 6.5-11.5. After filtration, the solid mass is shaken with 8 ml of 1 M hydrochloric acid and indium is determined by differential pulse polarography (DDP). Indium can alternatively be quantitatively adsorbed on [1-(2-pyridylazo)-2-naphthol]-naphthalene adsorbent packed in a column and determined similarly. The detection limit is 0.2 ppm (signal to noise ratio=2) and the linearity is maintained in the concentration range 0.8-125 ppm with a correlation coefficient of 0.9994 and relative standard deviation of +/-0.96%. Characterization of the electroactive process included an examination of the degree of reversibility. Various parameters such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of indium have been studied in detail to optimize the conditions for determination in various samples.
Taher
M A
MA
Department of Chemistry, Shahid Bahonar University of Kerman, POB 76175 133, Kerman, Iran.