A novel magnetic nanocomposite composed of graphene oxide (GO), silica (SiO2), and magnetite (Fe3O4), denoted as GO-SiO2/Fe3O4, was synthesized and evaluated as an efficient adsorbent for removing Sudan III dye from wastewater and chili sauce samples. The composite’s integration provided enhanced adsorption capacity, increased surface area, and convenient magnetic recovery, overcoming common limitations such as low efficiency and high operational costs. The synthesized sorbent was characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, vibrating-sample magnetometry, dynamic light scattering, zeta potential, thermogravimetric analysis, and Brunauer–Emmett–Teller surface area analysis. These characterizations confirmed the successful synthesis of the composite, verifying its structural integrity, surface functionality, magnetic properties, thermal stability, and high surface area suitable for efficient dye adsorption. Under optimum experimental conditions, optimized through multivariate chemometric analysis, 99.8% analyte recovery were observed. Detection and quantification limits were significantly improved from 0.74 and 2.04 mg/L to 0.06 and 0.19 mg/L after extraction, respectively. It showed an adsorption capacity of 85.6 mg/g and excellent linearity (R2 = 0.998), demonstrating its high performance. The intra-day and inter-day precisions with relative standard deviations were 4.42 and 4.58%, respectively. Additionally, the nanocomposite maintained over 90% adsorption efficiency after five reuse cycles, highlighting its sustainability and reusability. Practical tests validated the composite’s robustness and effectiveness in real wastewater and chili sauce samples.
Ayaz et al. (Sun,) studied this question.