Preconcentration and trace determination of copper (II) in Thai food recipes using FeO@Chi-GQDs nanocomposites as a new magnetic adsorbent.

This study describes the preparation, characterization, and application of a new magnetic chitosan-graphene quantum dots (FeO@Chi-GQDs) nanocomposite as an adsorbent for the preconcentration of Cu(II) in Thai food recipes or the so-called "Som Tam" (green papaya salad) prior to determination by inductively coupled plasma-optical emission spectrometry. The spectroscopic and magnetic properties along with the morphology and thermal property were analyzed using FTIR, EDX, XRD, TGA, VSM, and TEM. Preconcentration optimizations including pH, dosage of adsorbent, adsorption-desorption time, concentration and volume of elution solvent, sample volume and enrichment factor, and reusing time were investigated.