title: Inverse supercritical fluid extraction as a sample preparation method for the analysis of the nanoparticle content in sunscreen agents.
abstract: We demonstrate the use of inverse supercritical carbon dioxide (scCO2) extraction as a novel method of sample preparation for the analysis of complex nanoparticle-containing samples, in our case a model sunscreen agent with titanium dioxide nanoparticles. The sample was prepared for analysis in a simplified process using a lab scale supercritical fluid extraction system. The residual material was easily dispersed in an aqueous solution and analyzed by Asymmetrical Flow Field-Flow Fractionation (AF4) hyphenated with UV- and Multi-Angle Light Scattering detection. The obtained results allowed an unambiguous determination of the presence of nanoparticles within the sample, with almost no background from the matrix itself, and showed that the size distribution of the nanoparticles is essentially maintained. These results are especially relevant in view of recently introduced regulatory requirements concerning the labeling of nanoparticle-containing products. The novel sample preparation method is potentially applicable to commercial sunscreens or other emulsion-based cosmetic products and has important ecological advantages over currently used sample preparation techniques involving organic solvents.
authors.affiliation: Centre Suisse d'Electronique et de Microtechnique (CSEM), Bahnhofstrasse 1, 7302 Landquart, Switzerland; Institute for Chemical and Bioengineering, Department for Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland. Electronic address: david.mueller@csem.ch.
authors.forename: David
authors.initials: D
authors.lastname: Müller
authors.affiliation: Centre Suisse d'Electronique et de Microtechnique (CSEM), Bahnhofstrasse 1, 7302 Landquart, Switzerland.
authors.forename: Stefano
authors.initials: S
authors.lastname: Cattaneo
authors.affiliation: Postnova Analytics GmbH, Max-Planck-Str. 14, 86899 Landsberg am Lech, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Meier
authors.affiliation: Postnova Analytics GmbH, Max-Planck-Str. 14, 86899 Landsberg am Lech, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Welz
authors.affiliation: Feyecon Carbon Dioxide Technologies, Rijnkade 17a, 1382 GS Weesp, The Netherlands.
authors.forename: Tjerk
authors.initials: T
authors.lastname: de Vries
authors.affiliation: AHAVA Dead Sea Laboratories, 1 Arava Street, 70150 Lod, Israel.
authors.forename: Meital
authors.initials: M
authors.lastname: Portugal-Cohen
authors.affiliation: European Commission-Joint Research Centre, IHCP, via E. Fermi 2749 I, 21027 Ispra, VA, Italy.
authors.forename: Diana C
authors.initials: DC
authors.lastname: Antonio
authors.affiliation: European Commission-Joint Research Centre, IHCP, via E. Fermi 2749 I, 21027 Ispra, VA, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cascio
authors.affiliation: European Commission-Joint Research Centre, IHCP, via E. Fermi 2749 I, 21027 Ispra, VA, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Calzolai
authors.affiliation: European Commission-Joint Research Centre, IHCP, via E. Fermi 2749 I, 21027 Ispra, VA, Italy.
authors.forename: Douglas
authors.initials: D
authors.lastname: Gilliland
authors.affiliation: Institute for Chemical and Bioengineering, Department for Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland.
authors.forename: Andrew
authors.initials: A
authors.lastname: de Mello
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D025924:Chromatography, Supercritical Fluid; D031521:Fractionation, Field Flow; D053758:Nanoparticles / Q000032:analysis*; D012997:Solvents; D013473:Sunscreening Agents / Q000737:chemistry*; D014025:Titanium / Q000032:analysis
chemical_list: D012997:Solvents; D013473:Sunscreening Agents; C009495:titanium dioxide; D014025:Titanium
keywords: Field flow fractionation; Inverse supercritical fluid extraction; Nanoparticle separation; Sample preparation; Supercritical carbon dioxide