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1.
Forensic Sci Int ; 335: 111303, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35430503

RESUMEN

The aim of this study was to use instrumental neutron activation analysis and multivariate analysis to determine the provenance of Jamaican Cannabis sativa L. Sixty-three samples were collected from various areas in Jamaica, with no other data but their known or self-reported growing regions. The samples were analysed for Al, As, Br, Ca, Cd, Co, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc, Sm, Sr, V, and Zn. The resulting elemental data were statistically evaluated using agglomerative hierarchical cluster analysis and principal component analysis. Cluster analysis was able to group the samples into their known or reported growing regions with a high degree of accuracy. Principal component analysis was also able to elucidate some of the underlying geochemical factors that could explain the clustering. These included the underlying bauxitic geochemistry and the influence of fertilizer inputs. Of the analysed elements, Al, As, Cd, Co, Fe, K, La, Mg, Mn, Sc, Sm, V, and Zn appear to be most significant in identifying the growing regions of the cannabis samples. Results indicate the promise of this methodology with an increased dataset and potentially further refinement of the identifying elements.


Asunto(s)
Cannabis , Oligoelementos , Cadmio/análisis , Humanos , Jamaica , Análisis de Activación de Neutrones/métodos , Proyectos Piloto
2.
Bull Environ Contam Toxicol ; 107(1): 11-19, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34236454

RESUMEN

In the present study, sea urchin Sterechinus neumayeri tissues were used for the passive biomonitoring of toxic and trace elements at the Comandante Ferraz Station, Antarctica and compared to a pristine region (Botany). As, Ba, Br, Ca, Co, Cr, Fe, K, Na, Rb, Sc, Se and Zn concentrations were determined by instrumental neutron activation analysis (INAA), while toxic metals (Cd, Hg, Ni and Pb), and Cu were determined by atomic absorption spectrometry (GF-AAS). The findings were compared to other organisms commonly applied for biomonitoring purposes and to the sediment concentrations of each sampling region. Urchins from the Ferraz Station area presented higher Br, Co, Cr, Cs, K, Se and Zn levels than the pristine location. The results obtained herein suggest S. neumayeri can be applied to the biomonitoring of Cr and Zn. The present study also contributes to knowledge of the mineral composition of the sea urchin S. neumayeri.


Asunto(s)
Oligoelementos , Animales , Regiones Antárticas , Monitoreo Biológico , Monitoreo del Ambiente , Análisis de Activación de Neutrones , Erizos de Mar , Oligoelementos/análisis
3.
Microsc Microanal ; 25(6): 1331-1340, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31648656

RESUMEN

Our group has reported the imprint formation of biological material on polycarbonate nuclear track detectors by UV-C exposure, which is used as an approach to simultaneously visualize cell imprints and nuclear tracks coming from the boron neutron capture reaction. Considering that the cell nucleus has a higher UV-C absorption than the cytoplasm and that hematoxylin preferentially stains the nucleus, we proposed to enhance the contrast between these two main cell structures by hematoxylin staining before UV-C sensitization. In this study, several experiments were performed in order to optimize UV-C exposure parameters and chemical etching conditions for cell imprint formation using the SK-BR-3 breast cancer cell line. The proposed method improves significantly the resolution of the cell imprints. It allows clear differentiation of the nucleus from the rest of the cell, together with nuclear tracks pits. Moreover, it reduces considerably the UV-C exposure time, an important experimental issue. The proposed methodology can be applied to study the boron distribution independently from the chosen cell line and/or boron compounds.


Asunto(s)
Autorradiografía/métodos , Análisis de Activación de Neutrones/métodos , Coloración y Etiquetado/métodos , Rayos Ultravioleta , Boro/efectos de la radiación , Línea Celular Tumoral , Hematoxilina/metabolismo , Humanos , Oligoelementos/efectos de la radiación
4.
Appl Radiat Isot ; 146: 33-39, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30753982

RESUMEN

In this work, a brief review on nuclear reaction methods aimed at nitrogen assessment in organic matter is given, followed by a detailed application using a deuteron beam and (d,p) and (d,α) induced reactions on 14N to determine nitrogen content in single seeds This study covers the analysis of five wheat and four maize stable varieties, which showed up good (linear) correlation coefficients in comparison with corresponding Kjeldahl nitrogen analysis for each species. This method of analysis turns out to be a fast and non-destructive technique for protein determination in cereals, besides its extendibility to other plant products for human nutrition.


Asunto(s)
Grano Comestible/química , Análisis de los Alimentos/métodos , Proteínas de Granos/análisis , Nitrógeno/análisis , Deuterio , Rayos gamma , Humanos , Análisis de Activación de Neutrones , Isótopos de Nitrógeno/análisis , Radioisótopos de Nitrógeno/análisis , Triticum/química , Zea mays/química
5.
Environ Sci Pollut Res Int ; 25(3): 2045-2050, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28191615

RESUMEN

The quality of dog diets depends on adequate ingredients capable of providing optimal nutrition and free of contaminants, for promoting long-term health. Trace elements in 95 samples of dry food for dog puppies (n = 32) and adults (n = 63) of various brands were measured using instrumental neutron activation analysis (INAA). The mass fractions of most elements were within the permissible limits for dogs. Aluminum, antimony, and uranium presented fairly high levels in some samples, which may imply health risks. Aluminum mass fractions ranged from <21 to 11,900 mg/kg, in same brand, super-premium dog food. Antimony mass fractions ranged up to 5.14 mg/kg, with the highest values measured in six samples of dog food from the same producer. The mass fractions of uranium was found up to 4 mg/kg in commercial brands from five different producers.


Asunto(s)
Alimentación Animal/análisis , Perros , Oligoelementos/análisis , Animales , Antimonio/análisis , Inocuidad de los Alimentos , Análisis de Activación de Neutrones , Uranio/análisis
6.
J Environ Radioact ; 136: 131-9, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24953228

RESUMEN

Fossil bones are often the only materials available for chronological reconstruction of important archeological sites. However, since bone is an open system for uranium, it cannot be dated directly and therefore it is necessary to develop models for the U uptake. Hence, a radial diffusion-adsorption (RDA) model is described. Unlike the classic diffusion-adsorption (D-A) model, RDA uses a cylindrical geometry to describe the U uptake in fossil bones. The model was applied across a transverse section of a tibia of an extinct megamammal Macrauchenia patachonica from the La Paz Local Fauna, Montevideo State, Uruguay. Measurements of spatial distribution of Na, K, Ca, and Mg were also performed by neutron activation analysis (NAA). Gamma-ray spectrometric U-series dating was applied to determine the age of the bone sample. From U concentration profile, it was possible to observe the occurrence of a relatively slow and continuous uranium uptake under constant conditions that had not yet reached equilibrium, since the uranium distribution is a ∪-shaped closed-system. Predictions of the RDA model were obtained for a specific geochemical scenario, indicating that the effective diffusion coefficient D/R in this fossil bone is (2.4 ± 0.6)10(-12) cm(2)s(-1). Mean values of Na, K, Ca, and Mg contents along the radial line of the fossil tibia are consistent with the expected behavior for spatial distributions of these mineral elements across a modern bone section. This result indicates that the fossil tibia may have its mineral structure preserved.


Asunto(s)
Arqueología/métodos , Fósiles , Modelos Teóricos , Paleontología/métodos , Tibia/química , Uranio/química , Adsorción , Animales , Calcio/química , Difusión , Mamíferos , Metales Ligeros/química , Análisis de Activación de Neutrones , Espectrometría gamma , Uranio/análisis
7.
Sci Total Environ ; 454-455: 170-80, 2013 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-23542490

RESUMEN

Food web trophodynamics of total mercury (THg) and selenium (Se) were assessed for the double-basined ultraoligotrophic system of Lake Moreno, Patagonia. Each basin has differing proportions of littoral and pelagic habitats, thereby providing an opportunity to assess the importance of habitat (e.g. food web structure or benthic MeHg production) in the transfer of Hg and Se to top trophic fish species. Pelagic plankton, analyzed in three size classes (10-53, 53-200, and >200 µm), had very high [THg], exceeding 200 µg g(-1) dry weight (DW) in the smallest, and a low ratio of MeHg to THg (0.1 to 3%). In contrast, [THg] in littoral macroinvertebrates showed lower values (0.3 to 1.8 µg g(-1) DW). Juvenile and small fish species feeding upon plankton had higher [THg] (0.2 to 8 µg g(-1) muscle DW) compared to large piscivore fish species (0.1 to 1.6 µg g(-1) muscle DW). Selenium concentrations exhibited a much narrower variation range than THg in the food web, varying from 0.5 to 2.7 µg g(-1) DW. Molar Se:Hg ratios exceeded 1 for the majority of organisms in both basins, with most ratios exceeding 10. Using stable nitrogen isotopes as indicator of trophic level, no significant correlations were found with [THg], [Se] or Se:Hg. The apparent lack of biomagnification trends was attributed to elevated [THg] in plankton in the inorganic form mostly, as well as the possibility of consistent Se supply reducing the biomagnification in the food web of the organic portion of THg.


Asunto(s)
Cadena Alimentaria , Mercurio/metabolismo , Selenio/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Organismos Acuáticos/metabolismo , Argentina , Isótopos de Carbono/metabolismo , Monitoreo del Ambiente , Lagos , Espectrometría de Masas , Análisis de Activación de Neutrones , Isótopos de Nitrógeno/metabolismo
8.
Environ Monit Assess ; 185(7): 5375-86, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23142875

RESUMEN

A survey of the elemental contents of K, Mg, Mn, Na, Cl, Br, Cs, Co, Rb, Fe, Zn, Al, Ti, V, As, Ag, Au and Cd in liver, kidney and muscle was performed in specimens of Commerson's dolphins (Cephalorhynchus c. commersonii) from subantarctic waters. The concentrations were determined by Instrumental Neutron Activation Analysis and the specimens derives from animals incidentally caught in artisanal fishing nets. Liver had the highest concentrations of Fe, 897(79) µg g(-1) DW (dry weight) (average; standard deviation in parenthesis), kidney had the highest Cd, 35 (24) µg g(-1) DW; Cl, 9,200 (1,700) µg g(-1) DW; Na, 6,800 (1,100) µg g(-1) DW and Br, 73(12) µg g(-1) DW; and muscle the highest Mg 954 (71) µg g(-1) DW. Potassium and Cs concentrations in muscle and kidney ranged in 12,510-13,020 and 0.230-0.252 µg g(-1) DW, respectively; Zn and Mn concentrations were similar in liver and kidney (117-122.1 and 3.66-16.5 µg g(-1) DW, respectively). Silver was high in liver 5.4(5.0) µg g(-1) DW and kidney 1.2(2.7) µg g(-1) DW. Gold, Rb, Co and As had no differences among tissues. Likewise, as in other odontocete species, the concentrations of essential elements showed little variation between the specimens analyzed, since they are regulated biochemically; however, heavy metals showed high variability. This study constitutes the first large description of the elemental composition in Commerson's dolphins from subantarctic waters of the South Atlantic Ocean.


Asunto(s)
Delfines/metabolismo , Metales Pesados/metabolismo , Oligoelementos/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Océano Atlántico , Monitoreo del Ambiente , Femenino , Riñón/metabolismo , Hígado/metabolismo , Masculino , Metales Pesados/análisis , Músculos/metabolismo , Análisis de Activación de Neutrones , Oligoelementos/análisis , Contaminantes Químicos del Agua/análisis
9.
Environ Sci Pollut Res Int ; 19(8): 3307-16, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22427176

RESUMEN

PURPOSE: The differential ability of apple snail tissues, endosymbionts, and eggs to bioaccumulate several metals (Sb, As, Ba, Br, Zn, Cr, Fe, Hg, Se, and U) was investigated. METHODS: Metal concentrations were determined by neutron activation analysis in several tissues, endosymbionts, and eggs from mature apple snails cultured in either drinking water or reconstituted water (prepared with American Society for Testing and Materials type I water). RESULTS: The highest bioconcentration factors (BCFs) in the midgut gland were found for Ba, Zn, Se, As, U, Br, and Hg (in decreasing order), while the highest in the kidney were for Ba, Br, and Hg. The foot showed the highest BCFs for Ba, Hg, Br, and Se (in decreasing order). Calcified tissues (uterus, shell) and eggs showed low BCFs, except for Ba. Both C corpuscles and gland tissue showed statistically higher BCFs than K corpuscles for Ba, Fe, U, Br, and Sb. The concentration of most of the studied elements was significantly lower in tissues and endosymbionts obtained from snails cultured in reconstituted water instead of drinking water. Snails cultured in reconstituted water and then exposed or not to Hg, As, and U (at the maximum contaminant level allowed by the US Environmental Protection Agency) also resulted in high levels accumulated in midgut gland, endosymbionts and kidney. CONCLUSIONS: Our findings suggest that the midgut gland (and the symbionts contained therein), the kidney, and the foot of Pomacea canaliculata may be useful bioindicators of Hg, As and U pollution in freshwater bodies and that the unrestricted use of ampullariid snails as human and animal food must be considered with caution.


Asunto(s)
Agua Potable/química , Metales Pesados/metabolismo , Caracoles/metabolismo , Uranio/metabolismo , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodos , Animales , Femenino , Riñón/química , Metales Pesados/análisis , Análisis de Activación de Neutrones , Uranio/análisis , Contaminantes Químicos del Agua/análisis , Calidad del Agua
10.
Appl Radiat Isot ; 70(4): 589-94, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22316587

RESUMEN

The atmosphere of the Tula Industrial Corridor in Central Mexico is contaminated due to several industries including oil refining while station monitoring in this area are limited. Lanthanides are considered fingerprint of oil refinery activities, and La, Ce and Sm have been previously detected in this area using filters. The suitability of T. usneoides as a biomonitor assessing the La, Ce and Sm concentrations in Particulate Matter is evaluated by NAA. Results of both biomonitor and filters are highly correlated.


Asunto(s)
Monitoreo del Ambiente/métodos , Residuos Industriales/análisis , Material Particulado/análisis , Tillandsia , Monitoreo del Ambiente/instrumentación , Filtración , Humanos , México , Análisis de Activación de Neutrones
11.
J Hazard Mater ; 193: 264-71, 2011 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-21835546

RESUMEN

Heavy metal and trace element concentrations were examined in wheat grains and straw to elucidate associations between air pollution sources and soil variables. The mean wheat grain concentrations of Cr, Cu, Fe, Mn and Zn surpassed the tolerance limits stated in the international legislation for wheat grain and foodstuffs. When topsoil Ba, Co, Cr and Zn concentrations were higher than the legislation thresholds for agricultural and residential soils, wheat grain concentrations were also increased. In addition, Cr, Cu, Mn, Ni, Pb, and Zn revealed an immobilization effect of a cement plant and the atmospheric deposition input, with Cd in wheat grains being associated with a cement plant and industrial waste incinerator. The health risks arising from wheat grain consumption indicated that the inhabitants of Argentina are experiencing significant non-carcinogenic risks (Hazard Index = 3.311), especially when consuming wheat grains affected by metallurgical or chemical factories, as well as by air transportation from big cities.


Asunto(s)
Exposición a Riesgos Ambientales , Metales Pesados/análisis , Oligoelementos/análisis , Triticum/química , Carcinógenos/toxicidad , Metales Pesados/toxicidad , Análisis de Activación de Neutrones , Control de Calidad , Espectrofotometría Atómica , Oligoelementos/toxicidad
12.
Biol Trace Elem Res ; 144(1-3): 1289-94, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21735113

RESUMEN

This work focuses on the determination of chemical elements in sweet oranges of variety Valencia produced under organic and conventional systems using instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. The distribution of chemical elements was variable among the fruit parts with usually higher concentrations of Br, Ca, Ce, K, La, Na, Rb, and Sc in the peel. However, K, Na, and Rb also presented high values in the juice samples, while Fe and Zn were higher in the seeds. Differences between organic and conventional oranges were found for Br and Cu.


Asunto(s)
Citrus sinensis/química , Alimentos Orgánicos/análisis , Oligoelementos/análisis , Bebidas/análisis , Frutas/química , Espectrometría de Masas , Análisis de Activación de Neutrones , Semillas/química
13.
Artículo en Inglés | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP, SESSP-IBACERVO | ID: biblio-1064350

RESUMEN

The Amblyomma cajennense tick species is considered one of the most important and widespread species in Brazil. It salivary secretion has been a target ofseveral studies in biocenology, as the vector of diseases and in investigations related to antihemostatic properties andantitumor. To complement this investigation, neutron activation analysis (NAA) was applied to determine concentrationsof elements in saliva samples of this tick species. The saliva samples (50–554 lL) were collected at Butantan Institute (São Paulo city, Brazil) and they were investigated using the IEA-R1 nuclear reactor at IPEN/ CNEN-SP-Brazil. These data were compared with the values established for Amblyomma americanum and Amblyomma variegatum species emphasizing agreement only for Cl, K and Na with the A. americanum species,suggesting similarities in the mechanisms that regulate the osmotic pressure in this hematophagous animal. The knowledge of these limits contributes for tick saliva characterization as well as for the understanding of the many physiological processes, especially those related to salivary secretion.


Asunto(s)
Conejos , Garrapatas/clasificación , Garrapatas/parasitología , Hemolinfa , Análisis de Activación de Neutrones/instrumentación , Análisis de Activación de Neutrones/métodos
14.
Environ Pollut ; 159(8-9): 1991-5, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21396759

RESUMEN

After considering the particular problems of atmospheric pollution in megacities, i.e. agglomerations larger than 5 mio. inhabitants, with urbanization of World's population going on steadily, possibilities of active biomonitoring by means of green plants are discussed. Based on specific definitions of active and passive bioindication the chances of monitoring heavy metals in Sao Paulo megacity were demonstrated (first results published before). This is to show that there is need for increased use of bioindication to tackle the particular problems of megacities concerning environmental "health", the data to be processed according to the Multi-Markered-Bioindication-Concept (MMBC). Comparison to other work shows this approach to be reasonable.


Asunto(s)
Contaminantes Atmosféricos/análisis , Ciudades , Monitoreo del Ambiente/métodos , Metales/análisis , Tillandsia/química , Contaminación del Aire/estadística & datos numéricos , Atmósfera/química , Brasil , Análisis de Activación de Neutrones
15.
Appl Radiat Isot ; 68(3): 489-95, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20060307

RESUMEN

Since 2003, radiopharmaceuticals for medical diagnostic purposes have been produced at the Instituto de Engenharia Nuclear, in Brazil, using two cyclotron accelerators - CV-28 and RDS111. As a result of the ever increasing production, a diagnostic assessment to reduce neutron dose rates received by occupationally exposed individuals during irradiation processes has been developed. The purpose of this work is to present this assessment, which is currently being applied to both the Fluorine and Iodine targets of CV-28 and RDS111 cyclotron accelerators.


Asunto(s)
Radioisótopos de Cesio/análisis , Ciclotrones , Radioisótopos de Flúor/análisis , Neutrones , Exposición Profesional/análisis , Radiofármacos/química , Humanos , Análisis de Activación de Neutrones , Dosis de Radiación , Radiofármacos/síntesis química
16.
Appl Radiat Isot ; 68(4-5): 592-5, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-19833526

RESUMEN

The k(0) method for quantitative reactor neutron activation analysis (NAA) has been applied in several laboratories for the determination of multi-elemental concentrations in different materials. The general formula that yields the concentration value can be divided in two parts: one involving detection parameters and the other involving irradiation parameters. A rigorous uncertainty calculation must take into account the correlations between each of these parameters. The Nuclear Metrology Laboratory at IPEN has a research program intended to develop a methodology applying covariance analysis in order to obtain the overall uncertainty in the concentrations of different elements in a given sample, and the correlation between each pair of them. The present paper concentrates in the determination of the neutron spectrum shape factor alpha by two methods: Cd-covered and Cd-ratio, using experimental data obtained in the IEA-R1 research reactor. The final values for alpha were: (0.001+/-0.018) and (0.001+/-0.019) for the Cd-covered and Cd-ratio methods, respectively, in good agreement with each other.


Asunto(s)
Algoritmos , Modelos Químicos , Análisis de Activación de Neutrones/métodos , Análisis Espectral/métodos , Simulación por Computador , Modelos Estadísticos
17.
São Paulo; s.n; 2010. [100] p. ilus, graf.
Tesis en Portugués | LILACS | ID: lil-579173

RESUMEN

O interesse sobre o papel dos elementos traço na gênese de doenças, na mortalidade e na manutenção da saúde vem sendo cada vez maior. Este trabalho tem como objetivo determinar as concentrações séricas dos elementos: Br, Ca, Cl, Fe, Na, Rb, Se e Zn e correlacioná-las com os aspectos clínicos de uma população de idosos saudáveis. Foram considerados saudáveis os idosos sem senilidade sistêmica e sintomática, sendo selecionamos 101 idosos saudáveis, 33 (32,67%) homens e 68 (67,33%) mulheres com idade média de 71,7 ± 7,1 (60-98). O nível sérico de Se foi significativamente menor em pacientes mais idosos (p < 0.001). Em comparação com os valores de referência, o Br, Cl e Na apresentaram médias menores. Em relação ao sexo, os homens tiveram menores níveis de Br (p < 0,001) e de Se (p = 0,005) com maiores níveis de Fe (p < 0,001). Menores níveis de Se foram relacionados com menor escolaridade (p= 0.013). Os valores de Br estiveram muito abaixo dos valores de referência e a prática da atividade física correlacionou-se com menores níveis de Br (p= 0,008). Poderíamos questionar se os altos níveis de Br seriam prejudiciais ao envelhecimento saudável, se níveis baixos de bromo seriam marcadores de saúde em idosos ou até se existe relação entre hábitos de vida saudáveis com os níveis de Br. A partir dos 71,2 anos, os níveis séricos de selênio começam a cair mesmo em indivíduos saudáveis. Estudos adicionais deverão determinar se o monitoramento dos níveis séricos de selênio pode ser utilizado como marcador precoce do desenvolvimento de doenças e mortalidade.


Concern about the role of trace elements in the genesis of disease, mortality and health maintenance has been increasing. This study aims to determine serum concentrations of the elements: Br, Ca, Cl, Fe, Na, Rb, Se and Zn and correlate them with clinical features of a population of healthy elderly. Were considered healthy elderly people without senile systemic symptoms. We selected 101 healthy elderly, 33 (32.67%) men and 68 (67.33%) women with a mean age of 71.7 ± 7.1 (60-98). The serum level of Se was significantly lower in older patients (p <0.001). Compared with the reference values Br, Cl and Na diminished. Longer averages about sex men had lower levels of Br (p <0.001) and Se (p = 0.005) with higher levels of Fe (p <0.001). If lower levels were associated with less education (p = 0.013). Br values were well below the reference values and physical activity correlated with lower levels of Br (p = 0.008). One might question whether high levels of Br would be detrimental for healthy aging, if low levels of bromine were markers of health in the elderly or even if there is a relationship between healthy lifestyle habits with the levels of Br. From 71.2 years, serum levels of selenium begin to fall even in healthy individuals. Additional studies will determine if monitoring of serum levels of selenium can be used as a marker of early development of disease and mortality.


Asunto(s)
Envejecimiento , Análisis de Activación de Neutrones , Oligoelementos
18.
J Environ Biol ; 30(2): 213-6, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20121020

RESUMEN

Assays with Chlorella vulgaris Beijerinck Novakova, 1890 and Daphnia magna Straus, 1820 were performed to determine Cr and other elements concentration in tissues of both species by instrumental neutron activation analysis (INAA), after being exposed to 150, 280 and 350 microg l(-1) Cr(VI). Interaction among Cu, Zn, Fe and Cr were also registered. In the control of C. vulgaris, the amount of Cr was < 4 microg g(-1); in the treatments with Cr(VI) the values were 47, 82 and 100 folds greater than the control for the lowest, intermediate and highest concentrations tested respectively. In the control of D. magna, the amount of Cr was <3 microg g(-1); in the treatments with Cr(VI) the values were 14, 13 and 27 folds higher than the control for the lower, intermediate and higher Cr(VI) concentrations respectively and from 3 to 9 times less than for C. vulgaris These results show that C. vulgaris is very efficient accumulator of Cr(VI) from polluted waters, and in consequence, it is proposed to be used in phytoremediation procedures.


Asunto(s)
Chlorella vulgaris/metabolismo , Cromo/metabolismo , Daphnia/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Análisis de Activación de Neutrones
19.
J Agric Food Chem ; 56(13): 5222-5, 2008 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-18537259

RESUMEN

Multielement analysis of lemon juices from different Argentinean regions was carried out by instrumental neutronic activation analysis (INAA) with the aim at developing a reliable method in the traceability of the origin of lemon juices. This work presents a characterization of 44 lemon juice samples selected from three different geographical origins in the Northwest region of Argentina. Multivariate chemometric techniques such principal component analysis and lineal discriminant analysis (LDA) were used with the aim of classifying the juices and identifying the most significant parameters. Eleven elements were determined (Br, As, Na, Rb, La, Cr, Sc, Fe, Co, Zn, and Sb). The analytical method was validated by analyzing the standard reference material IAEA V-10 (hay powder); the results are within +/-10% of the reported values for the majority of the elements. Biplots of LDA scores for the INAA data illustrate clear separation between each sample.


Asunto(s)
Arsénico/análisis , Bebidas/análisis , Citrus/química , Metales Alcalinos/análisis , Metales Pesados/análisis , Elementos de Transición/análisis , Argentina , Frutas/química , Análisis de Activación de Neutrones/instrumentación
20.
Appl Radiat Isot ; 66(10): 1307-12, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18455924

RESUMEN

In this work, a comparative study of neutron activation analysis (NAA) was performed by the nuclear institutes: CDTN/CNEN-Brazil, CCHEN-Chile and the SCK.CEN-Belgium aiming to investigate some generic, manipulated and reference medicines largely commercialized in Brazil. Some impurities such as: As, Ba, Br, Ce, Co, Cr, Eu, Fe, Hf, Sb, Sc, Sm, Ti and Zn were found, and the heterogeneity of the samples pointed out the lack of an efficient public system of quality control.


Asunto(s)
Evaluación de Medicamentos/métodos , Evaluación de Medicamentos/normas , Medicamentos Genéricos/análisis , Medicamentos Genéricos/normas , Análisis de Activación de Neutrones/métodos , Análisis de Activación de Neutrones/normas , Brasil , Valores de Referencia
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