STUDY OF IRON DETERMINATION AT TRACE LEVELS

摘要

A method was established for preconcentration of Fe(III) using a strong base anion-exchange resin (Dowex 2x4) modified with Feron. The influence of the pH and volume of the aqueous solution, affecting the retention of Fe(III), was investigated. By working at pH 2.2, adjusted with buffer solution (0.2N HCl-0.2N KCl), the optimum sorption of iron was achieved. Fe(III) retained was stripped from the complexing resin with 5% ascorbic acid in 0.5 M HCl and then determined by atomic absorption spectrometry (AAS) at 248.3 nm. The atomic absorption varies linearly in the concentration range of 0.01-10 μg Fe(III) per mL. The sensitivity of the procedure for 1% absorption was found to be 0.01μg/mL. This preliminary study was applied to the improvement of the sensitivity in iron determination by AAS technique, after preconcentration of the metal ion in the chelate forming resin.