title: Incubation of solid state C60fullerene under UV irradiation mimicking environmentally relevant conditions.
abstract: Carbon-based nanomaterials, such as C60fullerenes, are expected to accumulate in soil due to direct release and deposition from the atmosphere. However, little is known about the environmental fate of these nanoparticles which may be susceptible to photochemical and microbial degradation. In the present work, C60was incubated for a period of 28 days and irradiated with UVA light. Three experiments were carried out where the fullerenes were either spiked onto a glass surface or added to quartz sand or sandy soil samples. At specific time intervals the samples were extracted and analysed by liquid chromatography coupled to UV or high resolution mass spectrometric (HRMS) detection. The fullerenes were degraded in all the treatments and the decay followed a pseudo-first-order rate law. In absence of a solid matrix, the half-life (t1⁄2) of the C60was 13.1 days, with an overall degradation of 45.1% that was accompanied by the formation of functionalized C60-like structures. Furthermore, mass spectrometric analysis highlighted the presence of a large number of transformation products that were not directly related to the irradiation and presented opened cage and oxidized structures. When C60was spiked into solid matrices the degradation occurred at a faster rate (t1⁄2of 4.5 and 0.8 days for quartz sand and sandy soil, respectively). Minor but consistent losses were found in the non-irradiated samples, presumably due to biotic or chemical processes occurring in these samples. The results of this study suggest that light-mediated transformation of the fullerenes will occur in the environment.
authors.affiliation: University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Science Park 904, 1098 XH Amsterdam, The Netherlands. Electronic address: carboni@ipgp.fr.
authors.forename: Andrea
authors.initials: A
authors.lastname: Carboni
authors.affiliation: University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Rick
authors.initials: R
authors.lastname: Helmus
authors.affiliation: University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: John R
authors.initials: JR
authors.lastname: Parsons
authors.affiliation: Dresden University of Technology, Soil Resources and Land Use, Pienner Str. 19, 01737 Tharandt, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Kalbitz
authors.affiliation: University of Amsterdam, Institute for Biodiversity and Ecosystem Dynamics, Science Park 904, 1098 XH Amsterdam, The Netherlands; KWR, Watercycle Research Institute, P.O. Box 1072, 3433 PE Nieuwegein, The Netherlands.
authors.forename: Pim
authors.initials: P
authors.lastname: de Voogt
mesh_terms: D002853:Chromatography, Liquid; D052918:Environmental Restoration and Remediation / Q000379:methods*; D037741:Fullerenes / Q000737:chemistry* / Q000528:radiation effects*; D006207:Half-Life; D013058:Mass Spectrometry; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry; D010777:Photochemistry; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D037741:Fullerenes; D012987:Soil; D012989:Soil Pollutants; C069837:fullerene C60
keywords: Degradation; Fullerenes; Irradiation; Soil; Transformation products