Philippe, Allan ; Košík, Juraj ; Welle, Alexander ; Guigner, Jean-Michel ; Clemens, Oliver ; Schaumann, Gabriele E. (2018)
Extraction and characterization methods for titanium dioxide nanoparticles from commercialized sunscreens.
In: Environmental Science: Nano, 5 (1)
doi: 10.1039/C7EN00677B
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
Sunscreens are an important source of TiO2 nanoparticles in surface waters. The fate and toxicity of these particles have not been fully addressed due to the gap between model nanoparticles usually used in studies and the more complex particles found in commercial products. Therefore, mild extraction methods for TiO2 nanoparticles from sunscreens were evaluated for providing more realistic nanoparticle samples for future studies. We propose two methods based on ultrafiltration and ultracentrifugation, respectively, for extracting TiO2 nanoparticles from sunscreens using a surfactant solution as the solvent. These methods were tested on eleven commercial sunscreens with differing compositions. The ultracentrifugation variant allows extracting 250 mg from approximately 5 g of sunscreen in one day. Recoveries for ultrafiltration and ultracentrifugation were 52–96% and 78–98%, respectively. Purification efficiency was determined for the ultracentrifugation variant by determining the avobenzone concentration in sunscreen extracts using UV-spectrometry and was high for all tested sunscreens. Transmission electron microscopy and dynamic light scattering revealed a high diversity in particle shape, although size parameters were comparable (average hydrodynamic diameter: 19–34 nm). Isoelectric points were below 4.6 for all sunscreen extracts. Time-of-flight secondary ion mass spectrometry revealed that probably all TiO2 particles were coated; most of them with PDMS, some others with Al- and Si-based materials. Comparison of images of particles inside the sunscreens using cryogenic transmission electron microscopy and of extracted particles showed that while the shape of the primary nanoparticles was not affected by the extraction, they were agglomerated inside the sunscreens. These agglomerates could be completely disrupted using ultrasonication. Therefore, the particles extracted in the present study can be considered as more environmentally relevant in terms of size, shape, surface charge and coating than model TiO2 nanoparticles.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2018 |
| Autor(en): | Philippe, Allan ; Košík, Juraj ; Welle, Alexander ; Guigner, Jean-Michel ; Clemens, Oliver ; Schaumann, Gabriele E. |
| Art des Eintrags: | Bibliographie |
| Titel: | Extraction and characterization methods for titanium dioxide nanoparticles from commercialized sunscreens |
| Sprache: | Englisch |
| Publikationsjahr: | 1 Januar 2018 |
| Verlag: | Royal Society of Chemistry |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Environmental Science: Nano |
| Jahrgang/Volume einer Zeitschrift: | 5 |
| (Heft-)Nummer: | 1 |
| DOI: | 10.1039/C7EN00677B |
| URL / URN: | https://doi.org/10.1039/C7EN00677B |
| Kurzbeschreibung (Abstract): | Sunscreens are an important source of TiO2 nanoparticles in surface waters. The fate and toxicity of these particles have not been fully addressed due to the gap between model nanoparticles usually used in studies and the more complex particles found in commercial products. Therefore, mild extraction methods for TiO2 nanoparticles from sunscreens were evaluated for providing more realistic nanoparticle samples for future studies. We propose two methods based on ultrafiltration and ultracentrifugation, respectively, for extracting TiO2 nanoparticles from sunscreens using a surfactant solution as the solvent. These methods were tested on eleven commercial sunscreens with differing compositions. The ultracentrifugation variant allows extracting 250 mg from approximately 5 g of sunscreen in one day. Recoveries for ultrafiltration and ultracentrifugation were 52–96% and 78–98%, respectively. Purification efficiency was determined for the ultracentrifugation variant by determining the avobenzone concentration in sunscreen extracts using UV-spectrometry and was high for all tested sunscreens. Transmission electron microscopy and dynamic light scattering revealed a high diversity in particle shape, although size parameters were comparable (average hydrodynamic diameter: 19–34 nm). Isoelectric points were below 4.6 for all sunscreen extracts. Time-of-flight secondary ion mass spectrometry revealed that probably all TiO2 particles were coated; most of them with PDMS, some others with Al- and Si-based materials. Comparison of images of particles inside the sunscreens using cryogenic transmission electron microscopy and of extracted particles showed that while the shape of the primary nanoparticles was not affected by the extraction, they were agglomerated inside the sunscreens. These agglomerates could be completely disrupted using ultrasonication. Therefore, the particles extracted in the present study can be considered as more environmentally relevant in terms of size, shape, surface charge and coating than model TiO2 nanoparticles. |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Materialdesign durch Synthese |
| Hinterlegungsdatum: | 12 Dez 2018 09:07 |
| Letzte Änderung: | 12 Dez 2018 09:07 |
| PPN: | |
| Sponsoren: | The authors thank the German Research Foundation (DFG) for financial support within research unit INTERNANO (FOR 1536 “ Mobility, aging and functioning of engineered inor- ganic nanoparticles at the aquatic – terrestrial interface ” ,, sub-projects SCHA849/1, The authors thank the Karlsruhe Nano Micro Facility (Karlsruhe Institute of Technology) for supporting ToF-SIMS measurements., The authors thank Dr. Wolfgang Fey for the support provided during ICP-MS measurements. |
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