Adsorption and desorption of the flavonoids on activated carbon impregnated with different metal ions

In this paper, four metal ions Mg 2+ , Al 3+ , Fe 3+ and Zn 2+ were loaded on the surface of activated carbon by impregnation method to prepare modified activated carbon. High-temperature calcination was used to activate the activated carbon loaded with the metal ions. Scanning electron microscopy, specific surface area and pore size analyzer, X-ray diffraction, and Fourier infrared spectroscopy were used to evaluate the structure and morphology of the modified activated carbon. The findings show that the modified activated carbon charactered in a large of microporous structures and specific surface area, both of which significantly improve the activated carbon absorbability. The study also involves the adsorption and desorption kinetics of the prepared activated carbon for three flavonoids. It was found that the prepared activated carbon had high adsorption efficiency for all three flavonoids, but the desorption efficiency of three flavonoids varied a lot. Naringenin is easier to be desorbed at alkaline condition, the elution percentage is 50% higher than that of the other two flavonoids. This difference provides a basis for the application of this type of activated carbon in the selective enrichment and separation of flavonoids.