Nanoparticle (NP) applications have recently gained more space in the development of many products, especially in cosmetology. The aim of the present study was to validate a single particle inductively coupled plasma mass spectrometry technique for the detection and quantification of gold nanoparticles (AuNPs) and gold ions (Au (i)) in different cosmetics currently marketed in Brazil. The size limit of detection for pure AuNPs was 22 nm, and a concentration limit of detection of 2.3×106 particles g−1 was achieved. The limit of detection for total gold was 0.02 μg L−1 obtained in standard mode conditions. The recovery achieved was 98% for dissolved Au and 109% for AuNPs; the relative standard deviation was <5%. This validated method was applied to cosmetic products (n= 10) from different national and international industrial producers. Most cosmetics analysed contained quantifiable amounts of dissolved gold (< 0.005-2.1 μg g−1) and only four contained quantifiable amounts AuNPs the variability of the results detected (< LOD – 9.3 × 108particles g−1). The products that contained the greatest amount of these metallic NPs were the artisanal products. The results demonstrate the importance of adequate quality control for cosmetics to ensure consumer safety.

DETECTION AND QUANTIFICATION OF SILVER NANOPARTICLES BY spICP-MS. The growing interest in nanotechnology has led to an increase in the production and application of nanoparticles worldwide. Due to the unique functional properties of nanoparticles, these materials are being used by many industries, including the agricultural and food sectors. Among the commercially available nanomaterials, it is possible to highlight those produced with silver nanoparticles. One of the most promising techniques for the analysis of metallic nanoparticles is the Inductively coupled plasma mass spectrometry (ICP-MS) performed in single particle mode (spICP-MS). However, the use of the technique in the detection and measurement of nanoparticles requires that the equipment be operated differently than when used to analyze dissolved metal solutions. Thus, this article presents the use of the spICP-MS technique for the measurement and quantification of nanoparticles, as well as their validation. The method proved to be adequate for the purpose, presenting a satisfactory result for the selectivity test and recovery of 83.7 (40 nm) and 77.6% (80 nm). The detection limits, determined for the most frequent size, dissolved silver concentration and particle concentration, were 17.5 nm, 0.736 ng mL-1;, 146 particles mL-1;, respectively. Thus, the results obtained indicated the possibility of using the technique to determine the size and concentration of silver nanoparticles.