Cloud point extraction assisted by silver nanoparticles for the determination of traces of cadmium using electrothermal atomic absorption spectrometry

Abstract

The presence of a low amount of silver nanoparticles (AgNPs) in a medium containing ammonium pyrrolidine dithiocarbamate (APDC) and cadmium ions facilitates the cloud point extraction of the Cd–APDC complex by Triton X-114. The metallic ion is completely transferred to the surfactant-rich phase and then measured by electrothermal atomic absorption spectrometry. Using a 20 mL aqueous sample containing 100 μg L⁻¹ AgNPs and 0.075% (w/v) Triton X-114, the enrichment factor of the cadmium complex is found to be 1050, which results in a detection limit of 1 ng L⁻¹. The procedure shows good selectivity and reproducibility close to 5%, and its reliability is verified by analyzing three water samples with a certified cadmium content. Results for other water samples as well as for beer and wine samples are also given.