Elemental speciation of As, Se and Fe in infant formulas is of prime importance in order to identify the sources of the specific chemical forms of trace elements. It enables to get better information about their metabolic pathways. In the case of As, it was found, that dietary exposure to inorganic As for children under 3 years old (including rice based food) is estimated to be about 2 to 3 fold that of adults. The objective of this study was to elaborate the HPLC- NAA method for speciation analysis of arsenic, selenium and iron in in infant formulas and food. In dependence on an element, appropriate extraction procedures have been used (waterbath or enzymatic). Anion-exchange (for As and Se) and size exclusion chromatography (for Fe) has been used for the separation of the individual species. Separated species, elemental standards and blank were irradiated for 1 h at thermal neutron flux of 1014 cm-2 s -1 (nuclear reactor Maria, Świerk, Poland). After appropriate cooling time (1-15 days), samples were measured by -spectrometry; the time of measurements varied between 3600 and 20000 s. Obtained results demonstrate, that using chromatographic separations coupled with NAA detection, enables to determine selected chemical forms of As, Se and Fe at low concentration level with good accuracy. It is especially important, because these elements are problematic for ICP-MS .
Acknowledgments: The studies were supported by the National Science Centre, in the frame of the scientific project: New analytical procedures for the determination of chosen Se, As and Fe chemical forms in infant formulas based on neutron activation analysis (No. 2014/15/B/ST4/05047).
- E. Chajduk, H. Polkowska-Motrenko: Application of ICP-MS, INAA and RNAA to the determination of some ‘‘difficult’’ elements in infant formulas. J. Radioanal. Nucl. Chem. (2017) 311:1347-1353