SSH EN ISO 5378:1998

Niseshte dhe produkte që rrjedhin prej saj - Përcaktimi i përmbajtjes së azotit me metodën Kjeldahl - Metoda spektrofotometrike

Starches and derived products - Determination of nitrogen content by the Kjeldahl method - Spectrophotometric method (ISO 5378:1978)

Scope

Destruction of organic matter by sulphuric acid in the presence of a compound catalyst (see ISO 1871), alkalization of the reaction products, destillation of the liberated ammonia and collection in a sulphuric acid solution, followed by measuring of the ammonium salt formed after the addition of Nessler reagent. The method is provided for contents less than 0,025 % (m/m). For greater contents, see ISO 3188.