A new approach towards simultaneous extraction of individual analytes based on the simultaneous application of multiple magnetic sorbents

Abstract

This paper reports a new approach for the simultaneous extraction of individual analytes based on the simultaneous application of multiple magnetic sorbents using a simple automated system. A mixture of toxic metals including Cd(II) and Cr(III) was selected as model analytes and two selective magnetic nano-sorbents were prepared for each analyte by modification of Fe₃O₄ nanoparticles with specific ligands cadion and ferron, respectively. The prepared sorbents were held using an external magnet in two parts of a loop. The sample solution was then passed through the loop leading to selective extraction of each analyte on the specified sorbent. Finally, the two sections of the loop were separated and each analyte was separately eluted and quantified using graphite furnace atomic absorption spectrometry. The factors affecting the designed system and the extraction efficiency were investigated and optimized. A preconcentration factor of 80 and detection limits of 0.7 and 6.8 ng L⁻¹ were achieved for Cd(II) and Cr(III), respectively. The method was successfully applied to the simultaneous extraction and determination of the target analytes in natural water samples.