Fluorine in eye shadow: Development of method using high-resolution continuum source graphite furnace molecular absorption spectrometry via calcium mono-fluoride with direct solid sample introduction

• Published in: Microchemical journal 2016-01, Vol.124, p.410-415
• Main Authors: Borges, Aline R., Duarte, Álvaro T., Potes, Mariana da L., Silva, Márcia M., Vale, Maria Goreti R., Welz, Bernhard
• Format: Article
• Language: English
• Subjects: Direct solid sample analysis; Eye shadows; Fluorine determination; High-resolution continuum source graphite furnace molecular absorption spectrometry
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2015.09.025

Eye shadows are cosmetics of different colors applied in the periocular area, composed by calcium carbonate, kaolin, titanium dioxide, zinc oxide, pigments, among others. In this study a method has been developed to evaluate the fluorine content in eye shadow samples using high-resolution continuum source graphite furnace molecular absorption spectrometry and direct solid sample analysis with calibration against aqueous standard solutions. The molecular absorption was measured using only the center pixel at 606.045nm and applying gas flow in the vaporization step. The diatomic molecule CaF was generated by the addition of 100μg Ca (as Ca(NO3)2·4H2O) as the molecule-forming reagent using a pyrolysis temperature of 1000°C and a vaporization temperature of 2400°C. The characteristic mass and limit of detection were 0.68ng and 2mg kg−1, respectively. The accuracy of the method was confirmed using two certified reference materials and by comparison with solubilization of the samples using tetramethylammonium hydroxide. Seven eye shadow samples from China, Brazil and France were analyzed to confirm the applicability of the method to real samples; the concentration of fluorine was found between 0.8 and 2.7gkg−1, however there is no legislation to monitor the maximum levels of fluorine in this cosmetic. •A method for fluorine determination in eye shadow samples using SS-HR-CS GF AAS was developed.•Diatomic molecule CaF was generated by the addition of Ca as the molecule-forming reagent.•Direct solid sample analysis was employed.•Accuracy of the method was confirmed using CRM and by comparison with solubilization using TMAH.•The investigated samples were from different colors and origins.