Inclusion of nitrate and nitrite in the Kjeldahl nitrogen determination of soils and plant materials using sodium thiosulphate

Autor:	R.C. Dalai, K. L. Sahrawat, R.J.K. Myers
Rok vydání:	1984
Předmět:	Aqueous solution Chromatography Sodium Inorganic chemistry Soil Science chemistry.chemical_element Nitrogen chemistry.chemical_compound chemistry Nitrate Soil water Nitrite Digestion Agronomy and Crop Science Kjeldahl method
Zdroj:	Communications in Soil Science and Plant Analysis. 15:1453-1461
ISSN:	1532-2416 0010-3624
DOI:	10.1080/00103628409367572
Popis:	Sodium thiosulphate was used in a modification of the regular Kjeldahl method for the determination of total N in soil and plant samples containing NO‐ 3‐N and NO‐ 2‐N. Quantitative recoveries of added 15N‐labelled and unlabelled N0‐ 3‐N (1000 μg N), NO‐ 2‐N (500 μg N), and NO‐ 3‐N (500 μg N) + N0‐ 2‐N (250 μg N) were obtained from soils, plant materials and adenine, even in the presence of water (up to 50 ml H?0/sample) when 5 g of Na2S203.5H20 as 25% aqueous solution was added to each sample before digestion. Moreover, this procedure does not require additional pretreatment of samples as does the salicylic acid‐sodium thiosulphate or KMnO4‐Fe modification of the Kjeldahl method, and therefore saves considerable time.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c2565e9bd8c9f9a02c2d7ad52b0cf294 https://doi.org/10.1080/00103628409367572 Zobrazit plný text záznamu