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Acesso ao texto completo restrito à biblioteca da Embrapa Pecuária Sudeste. Para informações adicionais entre em contato com cppse.biblioteca@embrapa.br.
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Biblioteca(s):  Embrapa Pecuária Sudeste.
Data corrente:  12/07/2006
Data da última atualização:  30/08/2013
Tipo da produção científica:  Artigo em Periódico Indexado
Autoria:  DONATI, G. L.; NASCENTES, C. C.; NOGUEIRA, A. R. de A.; ARRUDA, M. A. Z.; NÓBREGA, J. A.
Título:  Acid extraction and cloud point preconcentration as sample preparation strategies for cobalt determination in biological materials by thermospray flame furnace atomic absorption spectrometry.
Ano de publicação:  2006
Fonte/Imprenta:  Microchemical Journal, v.82, p.189-195, 2006.
Idioma:  Inglês
Conteúdo:  A thermospray flame furnace atomic absorption spectrometer (TS-FF-AAS) was employed for Co detennination in biological materiaIs. Cobalt presents a high atomization temperature and consequently poor sensitivity is obtained without changing its thennochemical behavior. The effect of different complexing agents on sensitivity was evaluated based on the fonnation of Co volatile compounds. A cloud point procedure was optimized for Co preconcentration for further improvement of sensitivity. Samples were treated with I moI I-I hydrochloric acid solution for quantitative extraction of Co without simultaneous extraction of Fe, since it is a strong interferent. After the extraction and preconcentration steps, a sample volume of 150 /lI was introduced into the hot Ni tube using air as carrier at a tlow-rate of 0.4 ml min- I. The best sensitivity was attained using ammonium pyrrolidinedithiocarbamate (APDC) and Triton X-114 was employed for implementation of the cloud point procedure. The detection limit obtained for Co was 2.1 /lg 1-1 and the standard deviation was 5.8% for a solution containing 100/lg I-I (n= 10). Accuracy was checked using two certified reference materiaIs (tomato leaves and bovine li ver) and results were in agreement with certified values at a 95% confidence leveI. Employing the developed procedure, Co were quantified in different biological materiaIs (plant and animal tissues).
Palavras-Chave:  Acid extraction; Cloud point extraction; Flame atomic absorption spectrometry; Thermospray; Tube in flame.
Thesaurus Nal:  cobalt.
Categoria do assunto:  --
Marc:  Mostrar Marc Completo
Registro original:  Embrapa Pecuária Sudeste (CPPSE)
Biblioteca ID Origem Tipo/Formato Classificação Cutter Registro Volume Status URL
CPPSE16293 - 1UPCAP - --PROCI-2006.00012DON2006.00012
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Acesso ao texto completo restrito à biblioteca da Embrapa Solos. Para informações adicionais entre em contato com cnps.biblioteca@embrapa.br.

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Biblioteca(s):  Embrapa Agrobiologia; Embrapa Solos.
Data corrente:  13/07/2015
Data da última atualização:  09/11/2021
Tipo da produção científica:  Artigo em Periódico Indexado
Circulação/Nível:  A - 1
Autoria:  RITTL, T. F.; NOVOTNY, E. H.; BALIEIRO, F. C.; HOFFLAND, E.; ALVES, B. J. R.; KUYPER, T. W.
Afiliação:  T. F. RITTL, WAGENINGEN UNIVERSITY; ETELVINO HENRIQUE NOVOTNY, CNPS; FABIANO DE CARVALHO BALIEIRO, CNPS; E. HOFFLAND, WAGENINGEN UNIVERSITY; BRUNO JOSE RODRIGUES ALVES, CNPAB; T. W. KUYPER, WAGENINGEN UNIVERSITY.
Título:  Negative priming of native soil organic carbon mineralization by oilseed biochars of contrasting quality.
Ano de publicação:  2015
Fonte/Imprenta:  European Journal of Soil Science, v. 66, n. 4, p. 714-721, Jul. 2015.
DOI:  https://doi.org/10.1111/ejss.12257
Idioma:  Inglês
Conteúdo:  Oilseed-derived biochar, a by-product of pyrolysis for biodiesel production, is richer in aliphatic compounds than the commonly studied wood-derived biochar, affecting both its mineralization in soil and its interaction with native soil organic carbon (nSOC). Here, we investigated the soil C sequestration potential of three different oilseed biochars derived from C3 plant material: soyabean, castor bean and jatropha cake. The chemical composition of these biochars was determined by elemental analysis (CHN) and 13C NMR spectroscopy. The cumulative CO2 efflux from 30-day laboratory incubations of biochar mixed with a sandy soil containing nSOC from C4 plants was measured as a proxy for mineralization rate. The relative contribution of each source to CO2 production was calculated based on the 13C-signatures of total CO2 efflux and the source materials (soil and biochars). Our results showed that: (i) castor bean biochar contained relatively large amounts of aliphatic compounds, resulting in a greater mineralization rate than soyabean and jatropha biochars; (ii) CO2 efflux from the soil-biochar mixtures originated mostly from the biochars, suggesting that these biochars contain rapidly decomposable compounds; and (iii) all three oilseed biochars decelerated nSOC mineralization. This negative priming effect appeared to be caused by different factors. We conclude that oilseed biochars have the potential to increase soil C stocks directly and increase soil C sequestration indirectl... Mostrar Tudo
Palavras-Chave:  Carbono do solo; Pinhão manso.
Thesagro:  Mamão; Soja.
Thesaurus NAL:  biochar.
Categoria do assunto:  P Recursos Naturais, Ciências Ambientais e da Terra
Marc:  Mostrar Marc Completo
Registro original:  Embrapa Solos (CNPS)
Biblioteca ID Origem Tipo/Formato Classificação Cutter Registro Volume Status
CNPAB41832 - 1UPCAP - DD
CNPS18951 - 1UPCAP - DD2015.00174
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