Determination of trace amounts of Pd(II) and Rh(III) ions in Pt–Ir alloy and road dust samples by flame atomic absorption spectrometry after simultaneous separation and preconcentration on non-modified magnetic nanoparticles

This work investigates the potential of magnetic Fe3O4 nanoparticles as an adsorbent for simultaneous separation and preconcentration of trace amounts of palladium and rhodium from Pt–Ir alloy and dust samples, prior to flame atomic absorption spectroscopy determinations. The effect of pH on the adsorption of analyte ions over a pH range from 3 to 12 was studied. The analyte ions quantitatively were adsorbed on magnetic Fe3O4 nanoparticles in the pH range of 10–12 and, then, magnetic nanoparticles (MNPs) were easily separated from the aqueous solution by applying an external magnetic field. Thus, no filtration or centrifugation was necessary. After extraction and collection of MNPs, the analyte ions were eluted using HCl 1.0 mol L−1. Under the best experimental conditions, linearity was maintained between 0.01–5.5 μg mL−1 for palladium, and 0.005–3.0 μg mL−1 for rhodium. Detection limits for palladium and rhodium were 2.9 and 1.4 ng mL−1 based on 3Sb. The relative standard deviation of eight replicate measurements of 0.5 μg L−1 of Pd(II) and Rh(III) ions was 1.9% and 1.7%, respectively. Finally, the method was successfully applied to the extraction and determination of palladium and rhodium ions in Pt–Ir alloy and road dust samples.