ANALYTICAL METHOD VALIDATION FOR THE IDENTIFICATION AND QUANTIFICATION OF DISSOLVED GOLD AND GOLD NANOPARTICLES IN COSMETICS PRODUCTS BY SINGLE PARTICLE INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

Abstract

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 × 108 particles 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