Dispersive solid phase extraction of copper and lead from water and lichen samples with an activated carbon@Fe/Mn/O composite derived from sucrose-based activated carbon

Abstract

In this study, an activated carbon@Fe/Mn/O composite was synthesized and characterized by X-ray diffraction, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, and Brunauer, Emmett, and Teller surface area and zeta potential measurements. As a green and economic approach, activated carbon was prepared from the hydrothermal carbonization of sucrose and subsequent KOH activation. The composite was used for the first time as an adsorbent for the vortex assisted dispersive solid phase extraction of copper and lead from samples. Copper and lead in solutions were determined by using flame atomic absorption spectrometry. The effects of preconcentration parameters on the recoveries of analytes were investigated. The optimum pH was found to be 6. The adsorbent amount was 50 mg. The adsorption and elution contact times were only 2 min. Elution was performed with 3 mL of 2 mol L⁻¹ HNO₃. The preconcentration factor and limit of detection of the method were found to be 33.3 and 0.46 μg L⁻¹ for Cu(II) and 50 and 2.68 μg L⁻¹ for Pb(II), respectively. The adsorbent showed a good selectivity against interfering ions and was reused 40 times. The trueness of the developed method was confirmed by analyzing three certified reference materials (TMDA-53.3 lake water, SPS-WW1 batch 114 wastewater, and BCR-482 lichen) and by spiking tap water, well water, and wastewater. The developed method was successfully applied to the determination of trace amounts of Cu and Pb in tap water, well water, wastewater, and lichen samples.