Determination of Macro, Micro and Toxic Elements using Argon-Based Plasma Spectroanalytical Methods in order to support Brazilian Regulations on Inorganic Constituents in Infant Foods

Abstract

Children's cereal-based foods and supplements are widely consumed by newborn and infant population. The Resolution RDC no. 193/2017 of the Brazilian National Health Surveillance Agency (ANVISA) established maximum tolerated limits (MTL) for toxic elements in infant foods aiming to control health risks. Complementarily, the determination of macro and microelements based on values of recommended daily intake (RDI) is regulated by Resolution RDC no. 269/2005. Two analytical procedures were developed using inductively coupled plasma mass spectrometry (ICP-MS) for determination of As, Cd, Sn and Pb and inductively coupled plasma optical emission spectrometry (ICP OES) for determination of Ca, Fe, K, Mg, Mn, Na, P and Zn attending both Brazilian regulations. Microwave-assisted acid digestion of solid samples was carried out in closed vessels using 7 mol L-1 HNO3. Two rice flours reference materials as well as addition and recovery experiments were applied to check accuracy. Recoveries ranged from 70 to 128% for ICP OES and from 82 to 128% for ICP-MS using internal standardization. The analytical procedure presented LOQs lower than maximum limits allowed by both regulations. Fifteen samples of cereal-based infant foods were analyzed and all analyte concentrations were lower than the respective MTLs recommended by RDC no. 193, except to Pb concentration in one milk flour sample. According to the RDI established by RDC no. 269 and the average concentrations of Ca, Fe, K, Mg, Mn, P and Zn in samples, it was possible to assign a minimum mass value of food that meets the recommendations of the Brazilian resolution for different population groups.