Rinawati, Dian Muthia, Hinaya Viebrienty, Sonny Widiarto, Agung Kiswandono, Fahamsyah H. Latief, Achmad Gus Fahmi, Iwan Syahjoko Saputra
This study reports the successful synthesis of graphene oxide (GO) from renewable corn cob agricultural waste using a modified Hummers method for its application as an adsorbent in Dispersive Solid Phase Extraction (DSPE) of Ciprofloxacin (CIP), established through the utilization of corn cob-derived GO as a low-cost, sustainable DSPE phase. Characterization confirmed the structural and chemical transformation: Scanning Electron Microscopy (SEM) showed the change from dense graphite particles to highly wrinkled, thin GO nanosheets, indicative of successful exfoliation. X-ray Diffraction (XRD) revealed the complete loss of the sharp graphite (002) peak at 2θ = 26.60° and the emergence of a broad, shifted peak at 2θ approximately 10°, confirming the increased interlayer spacing and the material's amorphous/highly disordered structure due to functional group intercalation. Energy-Dispersive X-ray Spectroscopy (EDX) verified the chemical change, showing a significant increase in oxygen content from 14.76 At% in graphite to 25.08 At% in GO. The DSPE process parameters were optimized using Response Surface Methodology (RSM) with a Box-Behnken Design. The optimal conditions for CIP adsorption were determined to be 20 mg of GO, a pH of 3.75, a CIP concentration of 752.92 ppb, and a contact time of 34.14 min. The GO exhibited a high maximum adsorption percentage of 99.26 %. This work demonstrates the significant potential of corn cob-derived GO as a low-cost, sustainable, and highly effective solid phase for environmental monitoring and extraction of pharmaceutical residues like CIP. © 2025 Elsevier Ltd
Department of Chemistry, Universitas Lampung, Bandar Lampung, 35145, Indonesia; Department of Mechanical Engineering, Universitas Nasional, Jakarta, 12520, Indonesia; Department of Cosmetic Engineering, Faculty of Industrial Technology, Sumatera Institute of Technology, South Lampung, 35365, Indonesia