MARIA JOSE AGUIRRE ARMELIN
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Capítulo IPEN-doc 28742 Aplicações da análise por ativação neutrônica para determinações multielementares em diferentes materiais2022 - ARMELIN, MARIA J.A.Neste trabalho é mostrado como INAA pode ser utilizada com sucesso para a solução de problemas analíticos que foram solicitados ao LAN (Laboratório de Análise por Ativação). Num primeiro caso, mostrou-se o desempenho da INAA como uma “técnica de referência”: 1) os valores das concentrações de As, Cd, Cr e Se, obtidos por INAA para fertilizantes minerais serviram como referência para checar os valores de concentrações obtidos pelo procedimento desenvolvido para determinar esses elementos por GF AAS e ICP OES nos mesmos fertilizantes; 2) os valores das concentrações de Au em carvão, obtidos por INAA serviram para avaliar a exatidão do procedimento de extrações em meio etanólico e alcalino do complexo Au(CN)3 do carvão ativado e posteriormente a determinação do Au por meio da espectrometria de absorção atômica de chama. Em outros casos, INAA foi aplicada para avaliar a eficiência de purificação da “Técnica de Refinamento Zonal” empregada para a purificação de cristais para serem utilizados como detectores de radiação X e gama e, também para avaliar a incorporação de nano partículas de Ag em cateter. Além do que mostrou ser uma opção para análise multielementar em matrizes orgânicas.Artigo IPEN-doc 28347 Multi-element contamination in soils from major mining areas in Northeastern of Brazil2021 - MONTALVAN-OLIVARES, D.M.; SANTANA, C.S.; VELASCO, F.G.; LUZARDO, F.H.M.; ANDRADE, S.F.R.; TICIANELLI, R.B.; ARMELIN, M.J.A.; GENEZINI, F.A.Mining has become one of the main factors in the global biogeochemical cycle of potentially toxic elements. Therefore, it is considered one of the anthropogenic activities with the greatest negative impact on the environment. These impacts are maximized in semiarid regions, where mining activities can lead to soil degradation and decrease in land productivity. This study aimed to assess the level of contamination in natural, urban, and agricultural soils of three important mining areas, where approximately 80,000 people live, and pollution levels have never been determined before. For this purpose, soil samples were collected around iron, uranium, and vanadium mines, as well as in the main human settlements of the region. The concentrations of 34 elements were determined by instrumental neutron analysis activation (INAA) and inductively coupled plasma optical emission spectrometry (ICP OES) techniques. Pollution indices (CF, EF, mCd, PLI, and REEP) revealed that there is a moderate to heavy level of pollution for 89% of the analyzed elements. Additionally, an extreme contamination level was observed in 78% of the samples, for at least one element. Statistical analyses were performed to identify patterns in the distribution and common sources of pollution. The results suggest that the concentrations for Al, Ba, Hf, Na, Pb, Rb, REE, Ta, Th, U, Zn, and Zr are associated with geogenic causes. However, the influence of anthropogenic sources such as agriculture and mining on the accumulation of these elements in soils should not be disregarded. In contrast, the contents of As, Br, Cd, Co, Cr, Cs, Cu, Fe, K, Mn, Ni, Sc, Ti, and V reflect the direct impact of anthropogenic sources.Artigo IPEN-doc 27243 Chia trace elements detection by neutron activation analysis2020 - CHIERENTIN, GABRIEL de S.; ARMELIN, MARIA J.A.; MASTRO, NELIDA L. delChia seed is an ancient grain that is becoming popular in modern food regimen for their nutritional value and functional properties, although many tables of food composition do not provide complete information about it. Trace and ultra-trace elements are indispensable for human health as they are involved in biochemistry regulations, such as transport and oxygen activation, electron transport, catalytic center in oxide reduction processes, catalytic center in acid-base processes and structural function. For both diet assessment and prescription, reference values for trace elements as recommended daily intake, recommended dietary allowance and tolerable upper intake level were established. Instrumental neutron activation analysis (INAA) is a noble method to identify and quantify trace and ultra-trace elements that has high sensitivity for many elements, has little or no sample contamination, resulting in low blank values, has virtually no matrix effects and multi element capability. The aim of the present work was to identify and quantify by INAA mineral elements of chia seeds. The results showed higher content of Ca, K, Zn and Fe when compared with data from the literature obtained by other analytical methods. Besides that, using INAA was possible to detect elements that was not commonly verified with others measuring methods.Artigo IPEN-doc 27211 Impact of ionizing radiation on cake from Brazilian macadamia nut (Macadamia integrifolia) after oil extraction2020 - RAO, INA P.; ARMELIN, MARIA J.A.; MASTRO, NELIDA L. delMacadamia oil extraction is commonly performed by cold pressing. This process presents low extraction yields, generating partially defatted meal as a byproduct. To take advantage of their important nutritious components, we propose to use the cake after lipid extraction as a food ingredient following the elimination of potentially hazardous microbiological contamination. Food irradiation is a mature, effective, broad spectrum and residuefree technology that can play an important role in food safety and food security. This study presents the impact of gamma irradiation on the residual cake from Brazilian macadamia pressing. An absorbed dose of 5 kGy reduced yeasts, molds and aerobic mesophilic bacteria below admissible maxima. The concentration of important elements like Ca, Se, Mg or Mn appeared higher in the cake than in the nut itself as measured by instrumental neutron activation analysis (INAA).