Engineered Fe₃O₄/SiO₂/TiO₂/rGO nanocomposites as high-efficiency magnetic adsorbents for cd(II) determination.

In this study, a magnetic dispersive solid phase extraction (MDSPE) method was developed for the determination of trace levels of cadmium ions in lemongrass (Cymbopogon citraus) tea infusion samples using flame atomic absorption spectrometry assisted with a matrix matching calibration strategy. Fe3O4/SiO2/TiO2/rGO nanocomposites (NCs) synthesized using a novel method were employed as adsorbents in the developed MDSPE procedure. Nanoparticles were characterized using various methods (XRD, SEM, EDS, FT-IR, and ICP-MS). Each parameter affecting adsorption and desorption in the Fe3O4/SiO2/TiO2/rGO based MDSPE-FAAS method was optimized. Under the optimum conditions, detection power was enhanced by 113-fold, compared to FAAS system. The calculated limit of detection (0.23 ng/g) and limit of quantification (0.76 ng/g) of the method are notably low. The developed procedure was applied to lemongrass tea infusion samples. The percentage recovery between 91.80% and 108.90% achieved with the matrix matching strategy.