Data/hora: 06/06/2024 04:41:46

Biblioteca(s): | Embrapa Agrobiologia.
Data corrente: | 27/06/1995
Data da última atualização: | 27/06/1995
Autoria: | ALVES, B. J. R.; BODDEY, R. M.; URQUIAGA, S. S.
Título: | A rapid and sensitive flow injection technique for the analysis of ammonium in soil extracts.
Ano de publicação: | 1993
Fonte/Imprenta: | Communication in Soil Science and Plant Analysis, New York, v.24, n.3/4, p.277-284, 1993.
Idioma: | Inglês
Conteúdo: | The steam distillation technique for the quantification of soil mineral nitrogen is not well adapted to estimate very low levels of NH4+ and NO3- such as those found in tropical pastures. In this paper we describe a flow injection analysis (FIA) technique for the direct estimation of soil ammonium in potassium chloride extracts. The technique is based on the salicylate/hypochlorite colorimetric reaction with the resulting colouration read at 647 nm. The speed of the reaction was increased by immersing the reaction coils in a water bath maintained at 70oC. The technique was capable of accurately quantifying ammonium to concentrations as low as 0.05 mg NH4+-N/L (equivalent to 0.25 mg NH4+-N/g dry soil) and sample thoughputs of at least 60 samples per hour couldbe achieved. It was found that amino acids would also give a positive colorimetric reaction but that in the ten tropical soils examined this was not a significant source of error.
Palavras-Chave: | Method; Mineral nutrient; N; Pasture.
Thesagro: | Amônia; Método; Mineral; Nitrogênio; Nutriente; Pastagem; Solo.
Thesaurus Nal: | ammonia; nitrogen; soil.
Categoria do assunto: | --
Registro original: | Embrapa Agrobiologia (CNPAB)
Exemplares: | CNPAB - (17987-1) - UPC - AP - -- -  -  - 16083 - DIS