Atomic absorption spectrometric determination of Al3+ and Cr3+ after preconcentration and separation on 3-mercaptopropionic acid modified silica coated-Fe3O4nanoparticles

Abstract

A new magnetic solid sorbent was synthesized using 3-mercaptopropionic acid grafted silica modified Fe₃O₄ magnetic nanoparticles. The sorbent was characterized by SEM, XRD, and FT-IR and used for solid phase extraction of Al³⁺ and Cr³⁺ ions. Al³⁺ and Cr³⁺ ions were measured by graphite furnace and flame atomic absorption spectrometry, respectively. The optimal extraction/preconcentration conditions including pH of sample solution, desorption conditions (type, concentration, and volume of the eluent), sonication time, sample volume, adsorbent amount, and interfering ions were studied. Under optimal conditions, the detection limits of 0.09 and 0.19 ng mL⁻¹ were obtained with a relative standard deviation (RSD%) of 2.1–5.2% for Al³⁺ and Cr³⁺ ions, respectively. The enrichment factors were found to be 99 and 92 for Al³⁺ and Cr³⁺ ions, respectively. The effects of various cationic interferences on percent recovery of Al³⁺ and Cr³⁺ ions were studied. The developed method was successfully applied for selective extraction and preconcentration of trace amounts of Al³⁺ and Cr³⁺ in biological and environmental samples.