Preconcentration and Separation of Iron and Cobalt Using Solid Phase Extraction and Their Determination by Flame Atomic Absorption Spectrometry

Abstract

The adsorptive potential of barium-strontium titanate based on glass fiber filter (BBST) for iron and cobalt ions were investigated and the conditions of adsorption and elution were studied. A solid phase extraction method has been developed to separate and concentrate trace amounts of iron and cobalt ions from aqueous samples for the measurement by flame atomic absorption spectrometry. By the passage of aqueous samples through barium-strontium titanate based on glass fiber filter, iron and cobalt ions adsorb quantitatively. The results showed that the barium-strontium titanate based on glass fiber filter had adsorption capacity towards the iron and cobalt ions when the pH value was not less than 4. The adsorption capacities of barium-strontium titanate based on glass fiber filter for iron and cobalt ions were found to be 15.29 mg/g and 5.02 mg/L, respectively. The iron and cobalt ions could be completely eluted by 0.5 g/L EDTA. The iron and cobalt were concentrated successfully and the pre-concentration factors were all not less than 100. A new method for determination of trace iron and cobalt in water based on barium-strontium titanate based on glass fiber filter and flame atomic absorption spectrometry determination was proposed. The detection limits of this method for iron and cobalt were 0.06 μg/L and 0.05 μg/L, respectively. The method has been applied to the determination of trace iron and cobalt ions in tap, lake and river water samples with successfully results.