LILIANA CASTRO
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Artigo IPEN-doc 25077 Stability assessment of a bovine kidney reference-material candidate2018 - CASTRO, LILIANA; MOREIRA, EDSON G.; VASCONCELLOS, MARINA B.A.; LANGE, CAMILA N.; PEDRON, TATIANA; BATISTA, BRUNO L.Reference materials are used worldwide and necessary for quality control purposes during analytical determinations. The present study describes the stability evaluation of a bovine kidney reference-material candidate. An isochronous layout was performed, in which the flasks involved are exposed at different temperatures for different time periods and then are analyzed at the same time at the end of the study. The mass fractions of ten inorganic constituents were determined using instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. Statistical analysis, univariate and multivariate, showed no significant differences in composition between units exposed to the different temperatures and times. The reference material may be transported under normal transportation conditions and the certified values and uncertainties will continue to be valid for a period of 2 years.Artigo IPEN-doc 24336 Use of INAA in the homogeneity evaluation of a bovine kidney candidate reference material2017 - CASTRO, LILIANA; MOREIRA, EDSON G.; VASCONCELLOS, MARINA B.A.Instrumental neutron activation analysis was used to evaluate the between bottle homogeneity and the minimum sample intake of a bovine kidney candidate reference material. The mass fractions of ten inorganic constituents were determined, obtaining satisfactory homogeneity results for all of them. Statistical analysis of the results was performed using a one way analysis of variance and multivariate techniques were applied as complementary techniques, confirming the usefulness of these techniques for homogeneity assessment.Artigo IPEN-doc 22834 Trace elements status in the terrain of an impounded vehicle scrapyard2017 - LANGE, CAMILA N.; FIGUEIREDO, ANA M.G.; ENZWEILER, JACINTA; CASTRO, LILIANAThe impact of a scrapyard of impounded vehicles in Sa˜o Paulo state on topsoil was evaluated for As, Ba, Co, Cr, Cu, Mo, Ni, Pb, V, Zn and rare earth elements (REEs). Mass fractions of all elements, except for Co, Cu, Mo and Zn, were higher than reference values. Hot spots were observed for most elements suggesting vehicular source. The geoaccumulation index showed moderate pollution of As. The enrichment factor pointed to a significant enrichment of As, Mo and Pb. The normalization of REEs to Earth’s crust values indicated a positive anomaly of Ce. The results indicate a potential risk to the soil quality of the scrapyard.Artigo IPEN-doc 22766 A Brazilian coal fly ash as a potential source of rare earth elements2017 - LANGE, CAMILA N.; CAMARGO, IARA M.C.; FIGUEIREDO, ANA MARIA G.M.; CASTRO, LILIANA; VASCONCELLOS, MARINA B.A.; TICIANELLI, REGINA B.Rare earth elements (REEs) have several applications and their market demands have increased. Recently, coal fly ash (CFA) has been considered as a source of these elements. The purpose of this study was to evaluate the REEs content in a CFA from a Brazilian coal power plant by instrumental neutron analysis, to classify it according to commercial purposes and to assess the weathering impact in the REEs content, since it is held in fields nearby the power plant. The results pointed no significant REEs leachability and indicated this CFA as a promising REEs source.