LILIANA CASTRO
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Artigo IPEN-doc 25791 Micro-homogeneity evaluation of a bovine kidney candidate reference material2019 - CASTRO, L.; MOREIRA, E.G.; VASCONCELLOS, M.B.A.The minimum sample intake for which a reference material remains homogeneous is one of the parameters that must be estimated in the homogeneity assessment study of reference materials. In this work, Instrumental Neutron Activation Analysis was used to evaluate this quantity in a bovine kidney candidate reference material. The mass fractions of 9 inorganic constituents were determined in subsamples between 1 and 2 mg in order to estimate the relative homogeneity factor (HE) and the minimum sample mass to achieve 5% and 10% precision on a 95% confidence level. Results ob-tained for HE in all the analyzed elements were satisfactory. The estimated minimum sample intake was between 2 mg and 40 mg, depending on the element.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.Resumo IPEN-doc 24542 Preparation of biological reference materials at LAN – IPEN – CNEN/SP2017 - MOREIRA, E.G.; MAIHARA, V.A.; CASTRO, L.; VASCONCELLOS, M.B.A.Three biological reference materials were prepared to be used in interlaboratory programs and/or proficiency tests, as well as, for calibration of analytical instruments and validation of analytical methods for environmental trace elements: A Perna perna mussel reference material was produced and certified by means of an interlaboratory comparison. The material was designed as a quality assurance tool for element biomonitoring studies along the Brazilian seashore. For the preparation of the Brazilian mussel reference material, 164kg of Perna perna (Linnaeus, 1758) mussels were purchased from a single producer, from Cocanha Beach in Caraguatatuba City, São Paulo State North Shore where mussels are cultivated by the longline system. After cleaning, freeze-drying and homogenization, the mussel samples were packed in 171 bottles and, the material was irradiated with a gamma ray dose of 5 kGy to enhance its stability. The certified mass fraction values and associated expanded uncertainties were obtained for Al, As, Ca, Cd, Cl, Co, Cu, Fe, K, Mg, Mn, Na, Ni, Se, Th and Zn at the certification campaign. A fish tissue reference material was produced in the context of an International Atomic Energy Agency (IAEA) project aiming analytical quality improvement for laboratories of the Latin American and Caribbean region. Whitemouth croake (Micropogonias furnieri), known as corvina, was the chosen species due to its low cost and high consumption in Latin America countries. For preparation, about 300kg of fish was collected and only the edible parts were used. After adequate processing, the fish material was bottled in 534 bottles with approximately 25g each. The reference values and associated expanded uncertainty (k = 2) were established for As, Cd, Cu, Fe, K, Mn, Na, Se and Zn; Finally, a bovine kidney reference material to be used in the quality control of meat products was prepared using 35 kg of fresh bovine kidney from cattle reared under controlled feeding conditions. The preparation resulted in a final batch of 175 flasks. It was possible to assign values to 20 elements with their respective uncertainties, being 9 certified values (As, Cu, Fe, K, Mg, Mn, Na, Se and Zn), 10 indicative values (Br, Ca, Cd, Cl, Co, Cs, Hf, Mo, P and Rb) and 1 as additional information (Hg). All the three reference material production projects took advantage of the unique metrological properties of Instrumental Activation Analysis (INAA) not only in the certification process but also in the homogeneity and stability assessment following ISO Guide 30 series recommendations.Tese IPEN-doc 24472 Preparo e caracterização de um material de referência de rim bovino2017 - CASTRO, LILIANAA utilização de materiais de referência é uma ferramenta fundamental na obtenção da comparabilidade e rastreabilidade das medições químicas. No presente trabalho foram desenvolvidas todas as etapas necessárias para a preparação, caracterização e certificação de um material de referência de rim bovino segundo os requisitos aceitos internacionalmente. Dado que o uso pretendido do material de referência é o controle de qualidade de produtos cárneos, alguns elementos com relevância nutricional ou que poderiam constituir contaminantes alimentares potenciais foram escolhidos para serem determinados. Foi estudada a homogeneidade do material tanto dentro quanto entre os diversos frascos preparados e a estabilidade do material em diferentes temperaturas e tempos, obtendo resultados satisfatórios. Para poder abarcar todos os elementos de interesse, os estudos de homogeneidade e estabilidade foram realizados utilizando-se três técnicas analíticas diferentes, análise por ativação neutrônica, espectrometria de massa com fonte de plasma acoplada indutivamente e espectrometria de absorção atômica de vapor frio. Para a avaliação dos estudos de homogeneidade e estabilidade foram utilizadas técnicas estatísticas univariadas clássicas como os testes de análise de variâcia e de regressão, e técnicas de análise multivariada como análise de componentes principais e análise de agrupamento hierárquico. Para atribuir valores às concentrações dos elementos de interesse, foi organizada uma comparação interlaboratorial com 33 laboratórios participantes, tanto de Brasil quanto do exterior. A avaliação conjunta dos resultados da comparação interlaboratorial e dos estudos de homogeneidade e estabilidade realizados possibilitou atribuir valores a 20 elementos com suas respectivas incertezas, sendo 9 valores certificados (As, Cu, Fe, K, Mg, Mn, Na, Se e Zn), 10 valores indicativos (Br, Ca, Cd, Cl, Co, Cs, Hf, Mo, P e Rb) e 1 como informação adicional (Hg).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 24063 Micro-homogeneity evaluation of a bovine kidney candidate reference material2017 - CASTRO, LILIANA; MOREIRA, EDSON G.; VASCONCELLOS, MARINA B.A.The minimum sample intake for which a reference material remains homogeneous is one of the parameters that must be estimated in the homogeneity assessment study of reference materials. In this work, Instrumental Neutron Activation Analysis was used to evaluate this quantity in a bovine kidney candidate reference material. The mass fractions of 9 inorganic constituents were determined in subsamples between 1 and 2 mg in order to estimate the relative homogeneity factor (HE) and the minimum sample mass to achieve 5% and 10% precision on a 95% confidence level. Results obtained for HE in all the analyzed elements were satisfactory. The estimated minimum sample intake was between 2 mg and 40 mg, depending on the element.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.Resumo IPEN-doc 22493 Rare earth elements content and leachability in coal fly ash from figueira coal power plant2016 - LANGE, CAMILA N.; VASCONCELLOS, MARINA B.A.; FIGUEIREDO, ANA M.G.; CAMARGO, IARA M.C. de; CASTRO, LILIANA; TICIANELLI, REGINA B.Resumo IPEN-doc 22492 Use of INAA in the homogeneity evaluation of a bovine kidney candidate reference material2016 - CASTRO, LILIANA; MOREIRA, EDSON G.; VASCONCELLOS, MARINA B.A.