Solvent‐free mechanochemical preparation of graphene oxide–Fe₃O₄ and its application in magnetic dispersive solid‐phase extraction of illegal dyes in food samples

Abstract

A simple, green, and efficient mechanochemical approach was developed herein to prepare tunable magnetic graphene oxide nanoparticles. The obtained nanoparticles were successfully used as adsorbents in a magnetic dispersive solid‐phase extraction method to extract three cationic dyes (i.e., thioflavine T, auramine‐O, and basic orange 2) found in food samples. Our proposed approach also utilized high‐performance liquid chromatography with ultraviolet detection. Several key variables affecting the extraction recovery were investigated. These included the sample pH, amount of extractant, extraction time, sample volume, elution solvent type and volume, and the stability and reusability of the magnetic graphene oxide nanoparticles. Under optimized conditions, the calibration curve was linear at a concentration range of 0.005‐1.0 μg/mL with a correlation coefficient of 0.9992‐0.9996. Moreover, the limits of detection were determined at 0.97‐1.35 μg/mL. The extraction mechanism was investigated via ultraviolet‐visible spectrophotometry and zeta‐potential analyses. The developed method was used to analyze the above‐mentioned cationic dyes in bean products and yellow fish samples. Notably, satisfactory spiked recoveries ranging from 90.7 to 104.9% were achieved.

Dispersive solid phase microextraction based on magnesium oxide nanoparticles for preconcentration of auramine O and methylene blue from water samples

“…The highest amount of dye extraction was obtained at pH = 7. The results of the present study are consistent with those of Hakami et al (2021), and Sha et al (2021) 42 , 43 .…”