Data/hora: 16/06/2024 19:13:06

Biblioteca(s): | Embrapa Agrobiologia.
Data corrente: | 05/10/2000
Data da última atualização: | 05/10/2000
Autoria: | ALVES, B. J. R.; ZOTARELLI, L.; RESENDE, A. S.; POLIDORO, J. C.; URQUIAGA, S.; BODDEY, R. M.
Título: | Rapid and sensitive determination of nitrate in plant tissue using flow injection analysis.
Ano de publicação: | 2000
Fonte/Imprenta: | Communications in Soil Science and Plant Analysis, New York, v.31, n.17-18, p. 2739-2750, 2000
Idioma: | Inglês
Conteúdo: | The determination of nitrate in waters and soil extracts by  the reduction of nitrate to nitrite by metallic or liquid reductants followed by the colorimetric determination of NO; using the Griess-Ilosvay reaction has been automated for use with air-segmented auto-analyzers or flow injection techniques. However, this technique is not applicable to plant extracts as organic species in the extracts inactivate the reduction columns. The objective of this study was to develop an automated procedure that would allow the determination of NO3" in plant extracts without the necessity of prior manual treatrnent. A flow injection technique was developed that successively traps and releases NO3" in an anion exchange column thereby removing pigments and other non-ionic and cationic species that otherwise interfere with conversion of NO3- to NO; on a copperized cadmium column. This reduction step is subsequently followed by standard Griess-Ilosvay colorimetric detection of this ion at a wavelength of 530 nm. The technique uses relatively simple and inexpensive equipment, principally a spectrophotometer equipped with a flow-through cell and a pen recorder output, a 6-channel peristaltic pump with accompanying tubing and a Perspex injector/commutator valve made in a laboratory workshop. The techinique  was found to avoid any significant interference of pigments or other organic compounds in the plant extracts, and the results compared favorably with those obtained using the manual transnitration techinique. Analysis time was approximately 1.5 min per sample and could detect NO3 concentration as low as 0.1 ug NO3 Nml in plant extracts.
Palavras-Chave: | Biological nitrogen fixation; BNF; FBN; Fixação biológica de nitrogênio; Soybean.
Thesagro: | Glycine Max; Nitrato; Soja; Tecido Vegetal.
Thesaurus Nal: | plant tissues.
Categoria do assunto: | --
Registro original: | Embrapa Agrobiologia (CNPAB)
Exemplares: | CNPAB - (792-1) - UPC - SP - -- -  -  - 0022517 - DIS