Differential Pulse Polarographic Determination of Trace Antimony in Standard Biological Samples after Preconcentration Using 2-Nitroso-1-naphthol-4-sulfonic Acid

A highly selective, sensitive, rapid and economical differential pulse polarographic method has been developed for the determination of trace amounts of antimony in various standard alloys and biological samples after adsorption of its 2-nitroso-1-naphthol-4-sulfonic acid - tetradecyldimethylbenzylammonium chloride on microcrystalline naphthalene in the pH range of 7.5-11.0. After filtration, the solid mass is shaken with 8-10 ml of 1 M hydrochloric acid (with preconcentration factor of 10) and antimony is determined by differential pulse polarography (DPP). Antimony can alternatively be quantitatively adsorbed on 2-nitroso-1-naphthol-4-sulfonic acid- tetradecyldimethylbenzylammonium-naphthalene adsorbent packed in a column (with preconcentration factor of 30) and determined similarly. In this case, 1.5 g of antimony can be cocentrated in a column from 300 ml of aqueous sample, where its cocentration is as low as 5 ng/ml.  Characterization of the electroactive process included an examination of the degree of reversibility. The results show that the irreversibility of antimony. Various parameters such as the effect of pH, volume of aqueous phase, HCl concentration, reagent concentration, naphthalene concentration, shaking time and interference of a number of metal ions on the determination of antimony have been studied in detail to optimize the conditions for determination in standard alloys and standard biological samples.