Determination of total and bioavailable of As and Sb in children’s paints using MSFIA system coupled to HG-AFS

In this work, the application of Doehlert design for the optimisation aiming the determination of As and Sb in gouache and tempera children's paints, using multi-syringe flow injection analysis (MSFIA) coupled to hydride generation atomic fluorescence spectrometry (HG-AFS), was proposed. The determination of total and bioavailable As and Sb in paint samples of various brands and colours was also investigated. The limits of quantification (LOQ) obtained for determination of As and Sb were 14.0 and 8.6 ng g–1, respectively. Accuracy and precision of the method were evaluated through recovery tests (by analyte addition method) at three levels for both elements, and analysis of certified reference materials of clay (CRM 052, Loamy Clay 1) and river water (SLRS-4). Twenty paint samples, manufactured in China, Italy, Spain and Brazil, were analysed. The concentrations of As varied between below LOQ (<14 ng g–1) and 136.0 ± 1.1 ng g–1 (average value of 101.0 ng g–1, n=10), and Sb between below LOQ (<8.6 ng g–1) and 74.0 ± 5.4 ng g–1 (average value of 21.7 ng g–1, n=17). The samples of children's paints presented concentrations of As and Sb below the maximum values established by National Institute of Metrology, Quality and Technology (INMETRO), as well as by the European legislation Directive 2009/48/EC. Based on the obtained results for total concentration of As and Sb, eight samples were selected to evaluate the migration, or bioavailablity of As and Sb after solubilisation in solution of HCl. The obtained results showed that for the eight analysed samples the concentration of both elements, after solubilisation in solution of HCl, were below the LOQ (<16.2 ng g–1 for As and <7.1 ng g–1 for Sb), corresponding to the limits of analytical concentrations of As and Sb established by INMETRO and Brazilian Association of Technical Standards (ABNT). The concentrations of As and Sb found, guarantee the safety for children when using the analysed paint samples, regarding these elements, since they do not cause any health risk. The analytical method for the determination of total and bioavailable of As and Sb in children's paints was efficient, accurate and precise.