Cosmetic chemical composition is a source of concern among consumers; since the increasing use of nanomaterials in these products has aroused global concern regarding their fate in biological systems, resulting in a demand for risk assessment. A number of new cosmetic formulations are based for example on pigment nanoparticles, since when they are used in makeup, exhibit greater homogeneity of the colour and a colouring which is both transparent and more intense. However, it is also well-known that Nickel (Ni), Cobalt (Co)and Chromium (Cr) might induce contact dermatitis in subjects with pre-existing allergy, and cosmetics represent an important source of sensitization, since they are used every day and are applied to the thinnest areas of facial skin. The Directive 76/768/EEC forbids the presence of Co, Ni and Cr in cosmetics but allows their presence in very low quantities, defined as “impurities”. The scientific literature proposes that Ni or Co should not exceed 5 ppm (µg/g) while the suggested amount to minimize the risk of sensitization in particularly sensitive subjects should be as low as 1 ppm. In this work some powder eye shadows, available for sale in Italy, were analysed to determine the Cr, Co and Ni concentrations and to describe the particle size distribution (PSD) of the water compatible particles contained in the samples. The total concentration of the elements was determined by Atomic Absorption Spectroscopy (AAS) after the sample acid digestion in a microwave oven. The Cr concentration was always higher than the other elements. In a sample containing about 150 mg/g of Cr, its water-soluble concentration was also determined, to investigate the ionic form of this element. The water compatible particles were extracted from the samples by using a ternary mixture of solvents (H2O/ethanol/exan), and the PSDs were determined through Sedimentation Filed Flow Fractionation (SdFFF) analyses. The fractograms were recorded at regular time intervals (4 hours) to follow the particle time evolution and to discriminate between the soluble and insoluble microparticles. The separation results were confirmed with SEM observations and when possible through specific element detection done by AAS.
Chromium, Cobalt and Nickel in Eye Shadows: Particle Size Distributions and Elements Concentration by SdFFF and AAS
CONTADO, Catia;PAGNONI, Antonella
2011
Abstract
Cosmetic chemical composition is a source of concern among consumers; since the increasing use of nanomaterials in these products has aroused global concern regarding their fate in biological systems, resulting in a demand for risk assessment. A number of new cosmetic formulations are based for example on pigment nanoparticles, since when they are used in makeup, exhibit greater homogeneity of the colour and a colouring which is both transparent and more intense. However, it is also well-known that Nickel (Ni), Cobalt (Co)and Chromium (Cr) might induce contact dermatitis in subjects with pre-existing allergy, and cosmetics represent an important source of sensitization, since they are used every day and are applied to the thinnest areas of facial skin. The Directive 76/768/EEC forbids the presence of Co, Ni and Cr in cosmetics but allows their presence in very low quantities, defined as “impurities”. The scientific literature proposes that Ni or Co should not exceed 5 ppm (µg/g) while the suggested amount to minimize the risk of sensitization in particularly sensitive subjects should be as low as 1 ppm. In this work some powder eye shadows, available for sale in Italy, were analysed to determine the Cr, Co and Ni concentrations and to describe the particle size distribution (PSD) of the water compatible particles contained in the samples. The total concentration of the elements was determined by Atomic Absorption Spectroscopy (AAS) after the sample acid digestion in a microwave oven. The Cr concentration was always higher than the other elements. In a sample containing about 150 mg/g of Cr, its water-soluble concentration was also determined, to investigate the ionic form of this element. The water compatible particles were extracted from the samples by using a ternary mixture of solvents (H2O/ethanol/exan), and the PSDs were determined through Sedimentation Filed Flow Fractionation (SdFFF) analyses. The fractograms were recorded at regular time intervals (4 hours) to follow the particle time evolution and to discriminate between the soluble and insoluble microparticles. The separation results were confirmed with SEM observations and when possible through specific element detection done by AAS.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
