BRUNO TAPPIZ

Projetos de Pesquisa
Unidades Organizacionais
Cargo

Resultados de Busca

Agora exibindo 1 - 10 de 16
  • Resumo IPEN-doc 30056
    Assessment of 238U and 226Ra activity concentration along the Amazon Tall Tower Observatory site
    2023 - TAPPIZ, B.; SILVA, P.S.C.; OSTERMANN, C.K.; LIMA, N.P.; BRAGUIN, L.N.M.; BOTIA, S.; LEVIN, I.; BUSTILLOS, O.V.
    The Amazon Tall Tower Observatory (ATTO) site is a region located within the Uatumã Sustainable Development Reserve (USRD), approximately 150 km northeast of Manaus city, in the Brazilian state of Amazonas. At the ATTO site, there are 3 tall towers, which are used for studies on the Amazon rainforest and its interaction with the soil and the atmosphere. The activity concentration of 238U and 226Ra was determined in soil samples collected in the footprint of the ATTO site by gamma spectrometry. The activity concentration of these radionuclides is important for understanding the 222Rn exhalation rate and 222Rn flux from soils. Knowledge of the 222Rn flux at the ATTO site can be useful for applications in atmospheric research, e.g., the 222Rn tracer method can be used to estimate local and regional emissions of greenhouse gasses; simulating 222Rn transport is a powerful tool for evaluation and validation of transport schemes in atmospheric chemical transport models. In this study, 39 samples collected from 13 sampling sites along a transect from the ATTO site to the river were analyzed. The highest activity concentrations were found in the Igapó forest (69 ± 2 Bq/kg for 238U and 47 ± 5 Bq/kg for 226Ra), a region near the Uatumã river with prevailing flooded black-water forest, whereas the lowest activity concentrations occurred in the Campina (Savanna on white-sand soils) and Campinanara (white-sand forest) ecosystems (18 ± 1 Bq/kg for 238U and 13 ± 2 Bq/kg for 226Ra), a transition area located between river terraces and the Terra Firme forest.
  • Resumo IPEN-doc 29563
    Comparison of 238U mass fraction measured by ICP–MS and Instrumental Neutron Activation Analysis techniques
    2022 - TAPPIZ, BRUNO; SILVA, PAULO S.C. da; OSTERMANN, CAROLINE; LIMA, NICOLE P. de; ANDRADE, MARIANA N. de; BUSTILLOS, OSCAR V.
    Introduction: Uranium is an element present in ambient air, water, soil and rocks [1]. The most abundant natural radioisotope of this actinide (238U) produces in its chain decay the radionuclide 222Rn [2], which is a tracer for atmospheric mixing and transport model validations [3]. The 238U activity concentration in superficial soil samples is a crucial parameter for some 222Rn flux map modeling methodologies [4]. Methods: In this study, 18 superficial soil samples were analyzed. The content of 238U was assessed using two techniques: (i) by the comparative method of the Instrumental Neutron Activation Analysis (INAA) [5] and by ICP–MS (ELAN 6000, PerkinElmer) [6]. Certified Reference Materials (CRM) SRM 1646a Estuarine Sediment and USG STM–2 were used both as comparators in the INAA technique and to ensure quality control. The normality and homoscedasticity of the data were evaluated. Finally, the Mann- Whitney U test [7] was used to assess whether or not there is a significant difference (α = 0.05) between the two techniques. Results: The z-score was calculated to ensure quality control. Z-scores values was obtained by the Modified Horwitz Equation [8], which takes into account the order of magnitude of the content of the analyte and is independent of the CRM uncertainties, unavailable for the CRM used. The z-score values obtained (n = 3) for the radionuclide 238U were 0.5 for the CRM USG STM–2 and -0.4 for SRM 1646a. The z-scores obtained are smaller than 2 therefore they are considered satisfactory [9]. Regarding the statistical parameters of the comparison between the techniques, the normality (Shapiro Wilk) was not verified (p = 0.02 for ICP-MS and p = 0.03 for INAA). The p-value for the test for equal variances (F test) was 0.71 Mann-Whitney U test was used instead of Student’s test due to the non-verification of the normality parameter in the data. The p-value from the Mann-Whitney test (0.51) indicates that there is no significant difference between the 238U content measured by the two techniques. Conclusions: Statistical analysis showed that there is no significant difference between the 238U mass fraction measured by the ICP–MS and the INAA – comparative method. In the future, certified reference materials will also be assessed by ICP–MS in order to corroborate this statistical comparison from a metrological point of view.
  • Resumo IPEN-doc 29562
    Evaluation of two statements methods by TD-GC-MS/TOF to BVOCs concentrations above the Amazon canopy
    2022 - ROVELO, BEATRIZ S.; OSTERMANN, CAROLINE; WILLIAMS, JONATHAN; TAPPIZ, BRUNO; ZANNONI, NORA; GUENTHER, ALEX; VEGA, OSCAR
    Introduction: Many biogenic volatile organic compounds (BVOCs) are chiral, meaning they naturally occur as two mirror images of the same molecule. Past and current studies on chiral BVOCs have highlighted the existence of regiospecific patterns [1] and their variability with time of the day, season and height [2]. To better elucidate the role of the tropical forest as a source or a sink of chiral VOC was determined the concentration in two distinctive GC-MS/TOF methods in Amazon rainforest. Methods: Air samples were collected in the Amazon Tall Tower Observatory (ATTO), located 150 km NE of Manaus, Brazil (02°08.752’S, 59°00.335’W) [3]. The site was chosen for having a tower enclosed into the canopy allowing it to measure above the canopy height. Samples were taken at 40m height during July/2019 and 2022 (wet season). The concentration of VOC in each sample was determined through GC-TOF-MS (Markes International, UK) at the Max Planck Institute for Chemistry and at University of California Irvine with the same type of detector. The GC-TOF-MS in Germany [4] is equipped with a thermal desorption unit, a chiral column and a TOF MS which operates in tandem mode and the TD-GC-MS/TOF in the USA is equipped with just one column [5]. Results: Data obtained from the chiral method shows that the concentration of enantiomeric compounds must be different than the simple column method used by the same analyser and mass detector. Conclusions: The second column in addition to TD-GC-MS/TOF can allow the enantiomeric BVOCs identification related to the amount of concentration measured in the Amazon rainforest.
  • Resumo IPEN-doc 29560
    Chiral BVOCs composition over the Amazon and Atlantic Rainforest by TD-GCxGC-TOF/MS
    2022 - OSTERMANN, CAROLINE; WILLIAMS, JONATHAN; ZANONNI, NORA; KESSELMEIER, JURGEN; TAPPIZ, BRUNO; GUENTHER, ALEX; VEGA, OSCAR
    Introduction: Many BVOCs are chiral, meaning they exist in two non-superimposable mirror image forms termed enantiomers. Enantiomers have identical physical properties, such as boiling point, density, and reactivity to atmospheric oxidants; however, they differ in their specific biological activity. Since most monoterpene measurements do not distinguish enantiomers, relatively little is known about the natural abundance and behavior of the chiral speciated molecules. Previous studies have reported regiospecific patterns across Tropical and Boreal ecosystems for α-pinene [1] and have used them as tracers of secondary processes in air and soil [2][3], highlighting the potential use of chiral compounds in air to decipher processes linking the biosphere with the atmosphere. To better understand the sources, dynamics and sinks of BVOC in the forest environment we have investigated chiral BVOC in the pristine Amazonian rainforest environment at Amazon Tall Tower Observatory (ATTO) is located 150 km from Manaus/BR and in Atlantic Forest located in the Ecological Immigrant Park (PEI) at São Paulo/BR in 2019. Methods: Samples collected in 2019, were thermally desorbed, separated and analyzed through a Bench-TOF select (TD-GCxGC-TOF/MS tandem ionization-14eV and -70eV) from Markes International, UK. First, all samples through to Thermo-Desorption, that one we separated in two desorption: Primary one we use at the cartridges during 10 min in 250°C and in the second one is for trap during 10 min with 250°C. In the GC the column is Dimethyl TBS Cyclodextrin based so the oven was settled in 5 min at 40°C and 1.5°C/min during the temperature increase from 40°C until 150°C and then 30°C/min from 150°C until 200°C. Results: The VOCs and their chirals analyzed are: (-/+) α- Pinene, (-/+) Camphene, (-/+) β- Pinene, (-/+) Limonene, these chiral are of extreme importance because the fact of obtaining the same chemical composition, but different geometries the (-) and (+) differ in nature in their function/aroma, for example the ( -) α- Pinene is found in pine and (+) α- Pinene is found in eucalyptus, such as (-) Limonene emitted by orange and (+) Limonene emitted by lemon. The separation method was specifically designed for the separation of chiral monoterpenes (C H ) and sesquiterpenes (C H ). A chiral column is therefore needed to separate the two enantiomers, standard columns for GC-MS, comparing to an online PTR-MS would not allow enantiomeric separation. Conclusions: It was concluded that the ratio between the pairs of enantiomeric concentrations show a temporal and spatial variability. In forests not disturbed by humans, was found a significant amount of (-) α-Pinene, and due to human interference located in the metropolitan region of São Paulo, (+) Limonene was the BVOC with the highest concentration.
  • Artigo IPEN-doc 28207
    Determination of trace elements of fish from the lower portion of Pomba river by neutron activation
    2021 - LINHARES, H.M.S.M.D.; COSTA, I.D.; TAPPIZ, B.; MORAIS, M.C.; SILVA, P.S.C.
  • Artigo IPEN-doc 28203
    Determination of 238-U and 232-Th in soil samples collected near the Amazon Tall Tower Observatory, Brazilian Amazon
    2021 - TAPPIZ, B.; SILVA, P.S.C.; CARVALHO, E.F.; BOTIA, S.; LINHARES, H.M.S.M.D.; OSTERMANN, C.K.; BUSTILLOS, O.V.
  • Resumo IPEN-doc 27952
    Naturally occurring radionuclides in a fish reference material
    2019 - MOREIRA, EDSON G.; SILVA, PAULO S.C.; MAIHARA, VERA A.; TAPPIZ, BRUNO; NISTI, MARCELO B.; SAUEIA, CATIA H.R.; CARVALHO, RICARDO N.
  • Artigo IPEN-doc 27861
    Expanded uncertainty assessment in fish samples analyzed by INAA and AAS
    2021 - TAPPIZ, BRUNO; MOREIRA, EDSON G.
    Measurement uncertainty was estimated following the EURACHEM guide (Quantifying Uncertainty in Analytical Measurement) for the elements As, Br, Cl, Co, Cr, Cs, Fe, K, Mg, Mn, Na, Rb, Sb, Se and Zn determined by In-strumental Neutron Activation Analysis (INAA) and for the elements Cd, Hg and Pb determined by Atomic Absorption Spectrometry (AAS) in the fillet of the most consumed fish species at São Paulo city, Brazil. INAA expanded uncertainties ranged from 1.0 to 21% and the main contributions were due the counting statistics of sample and pipetted standards. For AAS, expanded uncertainties ranged from 6.5 to 13% and the main contri-butions were associated to the calibration curves. Uncertainty results were compared with the standard devia-tions of the mass fraction in the fishes (n = 10). Due to the wide variability in the mass fraction in the analyzed fish tissues, explained by factors such gender, age, fat content and fishing location of the specimens of each spe-cies, standard deviations were greater than expanded uncertainties, which means that the natural variability of the elements determined is greater than the data dispersion associated with the analytical techniques. Hence the used techniques were adequate for the fish fillet samples analyses.
  • Artigo IPEN-doc 26156
    Measurement uncertainty evaluation in fish samples analyzed by INAA and AAS
    2019 - TAPPIZ, BRUNO; MOREIRA, EDSON G.
    Measurement uncertainty was estimated following the EURACHEM guide (Quantifying Uncertainty in Analytical Measurement) for the elements As, Br, Cl, Co, Cr, Cs, Fe, K, Mg, Mn, Na, Rb, Sb, Se and Zn determined by Instrumental Neutron Activation Analysis (INAA) and for the elements Cd, Hg and Pb determined by Atomic Absorption Spectrometry (AAS) in the fillet of the most consumed fish species at São Paulo city, Brazil. INAA expanded uncertainties ranged from 1.0 to 21% and the main contributions were due the counting statistics of sample and pipetted standards. For AAS, expanded uncertainties ranged from 6.5 to 13% and the main contributions were associated to the calibration curves. Uncertainty results were compared with the standard deviations of the mass fraction in the fishes (n = 10). Due to the wide variability in the mass fraction in the analyzed fish tissues, explained by factors such gender, age, fat content and fishing location of the specimens of each specie, standard deviations were greater than expanded uncertainties, which means that the natural variability of the elements determined is greater than the data dispersion associate
  • Dissertação IPEN-doc 25978
    Determinação de contaminantes inorgânicos em pescados consumidos em São Paulo como contribuição à garantia da segurança alimentar
    2019 - TAPPIZ, BRUNO
    O consumo do pescado é importante para a saúde humana pelo fato desse alimento ser fonte de proteína de alta qualidade, vitaminas, nutrientes essenciais e dois ácidos poli-insaturados ômega-3. Entretanto, o pescado também pode apresentar risco à saúde humana se estiver contaminado por substâncias tóxicas. Visando avaliar o teor de elementos essenciais e tóxicos, foram utilizado as técnicas de Análise por Ativação Neutrônica e Espectrometria de Absorção Atômica na determinação dos elementos As, Br, Cd, Cl, Co, Cr, Cs, Fe, Hg, K, Mg, Mn, Na, Pb, Rb, Sb, Se e Zn nos tecidos comestíveis (filés) de seis pescados dentre os mais consumidos na cidade de São Paulo: corvina - Micropogonias furnieri (Desmarest, 1823); pescada - Cynoscion leiarchus (Cuvier, 1830); robalo - Centropomus undecimalis (Bloch, 1792); sardinha - Sardinella brasiliensis (Steindachner, 1879); anchova - Pomatomus saltatrix (Linnaeus, 1766) e tainha - Mugil liza (Valenciennes, 1836). Para validar os métodos analíticos utilizados em relação à exatidão, foram utilizados o índice z e o valor de HorRat em materiais de referência certificados analisados sob as mesmas condições das amostras. Os elementos Br, K e Na foram determinados por duas modalidades de irradiação e o teste-t de Student foi utilizado para verificar se havia ou não diferença significativa entre as técnicas. Na determinação dos elementos essenciais e potencialmente tóxicos, foi possível a construção de banco de dados para os elementos Br, Cl, Co, Cs, Fe, K, Mg, Mn, Na, Rb, Se e Zn para potenciais futuras discussões. Para avaliar se havia ou não risco à segurança alimentar, foram comparado os teores de As, Cd, Hg e Pb com a legislação vigente no Brasil e com valores internacionais. Em relação à segurança alimentar, para os contaminantes Cd e Pb foram obtidos teores abaixo de todos os limites técnicos usados neste trabalho. Para As, a maior parte deve estar na forma orgânica, portanto, a determinação de Hg se mostrou determinante. De forma geral, não haveria perigo no consumo da sardinha, pescada, tainha, corvina e robalo, enquanto que para a anchova foi inconclusivo.