1. Investigation of zinc oxide particles in cosmetic products by means of centrifugal and asymmetrical flow field-flow fractionation
- Author
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Catia Contado, Thorsten Klein, Vanessa Sogne, and Florian Meier
- Subjects
Sample preparation ,Analytical chemistry ,chemistry.chemical_element ,ZnO particles ,Centrifugation ,Cosmetics ,02 engineering and technology ,Fractionation ,Zinc ,Asymmetrical flow FFF ,Cosmetic products ,01 natural sciences ,Biochemistry ,Dispersant ,NO ,Analytical Chemistry ,Nanomaterials ,chemistry.chemical_compound ,Particle extraction ,Particle sizing ,Chromatography ,010401 analytical chemistry ,Organic Chemistry ,Extraction (chemistry) ,General Medicine ,021001 nanoscience & nanotechnology ,Silane ,Fractionation, Field Flow ,0104 chemical sciences ,Europe ,chemistry ,Centrifugal FFF ,Particle ,Emulsions ,Zinc Oxide ,0210 nano-technology - Abstract
The dimensional characterization of insoluble, inorganic particles, such as zinc oxide ZnO, dispersed in cosmetic or pharmaceutical formulations, is of great interest considering the current need of declaring the possible presence of nanomaterials on the label of commercial products. This work compares the separation abilities of Centrifugal- and Asymmetrical Flow Field-Flow Fractionation techniques (CF3 and AF4, respectively), equipped with UV–vis, MALS and DLS detectors, in size sorting ZnO particles, both as pristine powders and after their extraction from cosmetic matrices. ZnO particles, bare and superficially modified with triethoxycaprylyl silane, were used as test materials. To identify the most suitable procedure necessary to isolate the ZnO particles from the cosmetic matrix, two O/W and two W/O emulsions were formulated on purpose. The suspensions, containing the extracted particles ZnO, were separated by both Field-Flow Fractionation (FFF) techniques to establish a common analysis protocol, applicable for the analysis of ZnO particles extracted from three commercial products, sold in Europe for the baby skin care. Key aspects of this study were the selection of an appropriate dispersing agent enabling the particles to stay in stable suspensions (>24 h)and the use of multiple detectors (UV–vis, MALS and DLS) coupled on-line with the FFF channels, to determine the particle dimensions without using the retention parameters. Between the two FFF techniques, CF3 revealed to be the most robust one, able to sort all suspensions created in this work.
- Published
- 2017
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