Determination of Rhodium in Soil by Dispersive Solid-Phase Extraction (DSPE) with Manganese Ferrite Nanoparticles and Flame Atomic Absorption Spectrometry (FAAS)

Abstract

Manganese ferrite (MnFe2O4) nanoparticles-assisted dispersive solid-phase extraction (MF-DSPE) was developed for the determination of rhodium (Rh) in soil samples at low levels with good accuracy and precision by flame atomic absorption spectrometry (FAAS). The synthesis of MnFe2O4 nanoparticles was carried out in a microwave system by a rapid procedure. The pH, buffer volume, sorbent mass, sample volume, eluent volume/concentration, and mixing time were identified with univariate optimization. Under the optimal conditions, the limits of detection (LOD) and quantitation (LOQ) were 4.4 and 14.7 µg L−1, respectively. The sensitivity was improved by 121.9-fold based upon comparison of the limits of detection with and without preconcentration. The applicability was investigated by spiking rhodium into soil extracts, and good recovery results between 91.2% and 122.2% were achieved using matrix matching calibration. The results showed that MF-DSPE-FAAS determines low levels of rhodium in soil with good accuracy and precision.