Magnetic dual task-specific polymeric ionic liquid nanoparticles for preconcentration and determination of gold, palladium and platinum prior to their quantitation by graphite furnace AAS

Abstract

The authors describe a hybrid of magnetic task-specific poly(ionic liquid) containing dual task-specific sites in an approach to both preconcentrate and quantify gold(III), palladium(II) and platinum(IV). The hybrid was obtained by successive alkaline coprecipitation, sol-gel, quaternization, elimination, anion exchange and polymerization. The material was characterized by scanning electron microscopy, transmission electron microscopy, FTIR spectroscopy, thermal gravimetric analysis, X-ray photoelectron spectrometry, X-ray diffractometry, and vibrating sample magnetometry. It was applied as an effective sorbent for magnetic solid-phase extraction of gold(III), palladium(II) and platinum(IV) ions. The effects of sample pH, amount of adsorbent, extraction time, eluent concentration and volume were optimized. Following elution with a thiourea/HCl solution, the ions were quantified by graphite furnace AAS. The calibration plot is linear in the 50 to 350 ng·L−1 gold(III) concentration range, in the 50 to 650 ng·L−1 palladium(II) concentration range, and in the 150 to 2100 ng L−1 platinum(IV), respectively. Other figures of merit for noble metals determination, respective, include (a) detection limits of at 19.7, 22.3 and 107.0 ng·L−1, (b) enrichment factors of 197, 174 and 168; and (c) reproducibilities (expressed as relative standard deviations) of 2.1%, 1.4% and 1.5%. In our perception, the method excels by its high sensitivity and preconcentration capability. It was successfully applied to the determination of gold(III), palladium(II) and platinum(IV) in certified reference materials and (spiked) real samples.