A procedure to determine the presence of nano- or micro- TiO2 particles in commercial cosmetic formulations, which may have a daily use, is proposed. Two identificative techniques the Square Wave Voltammetry (SWV) and ICP-AES were employed to determine the amount of TiO2 in six foundation creams sold in Italy and USA. A new SWV method, based on an acidic digestion microwave-assisted of the sample, has been set up and the results were compared and critically commented with those obtained by the established ICP-AES method. The analytical procedure was verified by analyzing the P-25 Degussa sample. The sizes of the particles contained in the foundations were investigated through Sedimentation (SdFFF) and the Flow Field-Flow Fractionation (FlFFF) by analyzing aqueous slurries obtained from the foundation through a solvent extraction procedure. The FFF techniques sinergically coupled with the ICP-AES allowed to assess the sizes of the TiO2 particles. The content of the extracted slurries was also checked by TEM observations.
Characterisation of TiO2 pigments in commercial foundation creams: a synergic use of the ICP-AES, square wave voltammetry and sedimentation FFF techniques
CONTADO, Catia;PAGNONI, Antonella
2011
Abstract
A procedure to determine the presence of nano- or micro- TiO2 particles in commercial cosmetic formulations, which may have a daily use, is proposed. Two identificative techniques the Square Wave Voltammetry (SWV) and ICP-AES were employed to determine the amount of TiO2 in six foundation creams sold in Italy and USA. A new SWV method, based on an acidic digestion microwave-assisted of the sample, has been set up and the results were compared and critically commented with those obtained by the established ICP-AES method. The analytical procedure was verified by analyzing the P-25 Degussa sample. The sizes of the particles contained in the foundations were investigated through Sedimentation (SdFFF) and the Flow Field-Flow Fractionation (FlFFF) by analyzing aqueous slurries obtained from the foundation through a solvent extraction procedure. The FFF techniques sinergically coupled with the ICP-AES allowed to assess the sizes of the TiO2 particles. The content of the extracted slurries was also checked by TEM observations.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
