Determination of Arsenic, Cadmium, Cobalt, Chromium, Nickel, and Lead in Cosmetic Face-Powders: Optimization of Extraction and Validation

An analytical method for the quantification of toxic metals in face-powders is presented and discussed. Acid digestion with HNO3-H2O2 or HNO3-HCl was performed and compared with total digestion by HF. The digestion with HNO3-H2O2 was the most suitable for these purposes. Analyses were performed by inductively coupled plasma atomic emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS), whose performances were compared by analyzing three different certified reference materials. The analysis of five commercial face-powders revealed the presence of all the considered metals in the range 0.06–8.0 µg/g. To simulate the bioaccessibility of metals in physiological conditions, a digestion with a simulated sweat solution was performed. In this case, the analysis of the same face-powder samples provided results below the limit of quantification, suggesting low bioaccessibility of the considered trace elements.