Chemically functionalized γ-alumina with Alizarin red-s for separation and determination of trace amounts of Pb(II) and Ag(I) ions by solid phase extraction-Flame Atomic Absorption Spectrometry in environmental and biological samples

A novel column solid phase extraction was developed for the determination of traces of lead and silver in various samples. An alumina-sodium dodecyl sulfate (SDS) coated on with Alizarin red-s was used for preconcentration of lead and silver ions prior to determination by flame atomic absorption spectrometry. Lead and silver were adsorbed quantitatively on a modified column due to its complexation with Alizarin red-s and then eluted using 5.0 mL 4.0 mol L−1 phosphoric acid. The influences of the analytical parameters such as pH, solid phase amount, ligand amount, types and concentration of eluting agent were investigated. The loading capacity of adsorbent for Pb and Ag were found to be 2.3 and 2.1 mg g−1. The detection limits were 18.0 and 55.0 μg L−1 for lead and silver respectively, applying a preconcentration factor of 100.0. The relative standard deviation under optimum conditions is lower than 2.0%. The presented procedure was successfully applied for the determination of analytes content in real samples. The results were obtained and are in good agreement with the reported method.