Simultaneous degradation of the anticancer drugs 5-fluorouracil and cyclophosphamide using a heterogeneous photo-Fenton process based on copper-containing magnetites (Fe3-xCuxO4)

Author(s)

Emidio, Elissandro Soares ^{[1, 2]} ; Hammer, Peter ^[1] ; Pupo Nogueira, Raquel F. ^{[1, 2]}

Affiliation

^[1] Sao Paulo State Univ UNESP, Inst Chem, Araraquara, SP - Brazil

^[2] Unesp, Natl Inst Alternat Technol Detect Toxicol Evaluat, Inst Chem, POB 355, BR-14800900 Araraquara, SP - Brazil

• Document type: Journal article
• Source: Chemosphere; v. 241, FEB 2020.
• Web of Science Citations: 0

Abstract

The effect of substitution of iron by copper in the magnetite lattice was investigated in terms of the catalytic activity in the heterogeneous photo-Fenton process. The physicochemical properties of the Fe3-xCuxO4 nanoparticles were characterized by X-ray diffraction (XRD), X-ray fluorescence (WD-XRF), specific surface area measurements, field emission scanning electron microscopy (FEG-SEM), and X-ray photoelectron spectroscopy (XPS). Copper-modified magnetite showed higher catalytic activity for H2O2 conversion to HO center dot (estimated using 7-hydroxycoumarin), compared to pristine magnetite (Fe3O4). Consequently, improved degradation of the anticancer drugs 5-fluorouracil (5-FU) and cyclophosphamide (CP) was observed, with high efficiencies achieved using Fe2.75Cu0.25O4 (0.125 g L-1) and 15 mmol L-1 H2O2, at pH 6.5, which resulted in complete degradation of 7.7 mu mol L-1 5-FU and CP after 150 min. Low leaching of Cu and Fe demonstrated the stability of the catalyst in the Fenton process, with high catalytic activity (>90%) maintained after use in 4 cycles. The addition of radical scavengers such as methanol, tert-butanol and iodide ions indicated that surface-bonded hydroxyl radicals played a major role in the degradation of 5-FU and CP in the Fe3-xCuxO4/H2O2 system. The substitution of octahedral Fe(II) sites of the magnetite lattice by Cu(II) and the partial oxidation of Cu(I) to Cu(II) and Fe(II) to Fe(III) on the catalyst surface after the Fenton reaction were confirmed by analysis of the XPS spectra. (C) 2019 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 14/50945-4 - INCT 2014: National Institute for Alternative Technologies of Detection, Toxicological Evaluation and Removal of Micropollutants and Radioactivies
• Grantee: Maria Valnice Boldrin
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/11373-0 - Degradation of anticancer drugs in hospital effluent by heterogeneous photo-Fenton process mediated by modified magnetites and iron mining residues
• Grantee: Elissandro Soares Emídio
• Support Opportunities: Scholarships in Brazil - Post-Doctoral