Differential pulse polarographic determination of tin in alloys and environmental samples after preconcentration with the ion pair of 2-nitroso-1-naphthol-4-sulfonic acid and tetradecyldimethylbenzylammonium chloride onto microcrystalline naphthalene or by column method

A highly selective, sensitive, rapid and economical differential pulse polarographic method has been developed for the determination of trace amount of tin in various standard alloys and environmental samples after adsorption of its 2-nitroso-1-naphthol-4-sulfonic acid-tetradecyldimethylbenzylammonium chloride on microcrystalline naphthalene in the pH range of 8.7-10.6. After filtration, the solid mass is shaken with 8-10 ml of 3.5 M hydrochloric acid and tin is determined by differential pulse polarography (DPP). Tin can alternatively be quantitatively adsorbed on 2-nitroso-1-naphthol-4-sulfonic acid-tetradecyldimethylbenzylammonium-naphthalene adsorbent packed in a column and determined similarly. The detection limit is 0.15 mug ml(-1) (signal to noise ratio=2) and the linearity is maintained in the concentration range 0.5-220 mug ml(-1) with a correlation coefficient of 0.9995 and relative standard deviation of +/-0.88%. 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 tin has been studied in detail to optimize the conditions for determination in standard alloys and environmental samples.