ISO 5378:1978 PDF
Starches and derived products — Determination of nitrogen content by the Kjeldahl method — Spectrophotometric method
Starches and derived products — Determination of nitrogen content by the Kjeldahl method — Spectrophotometric method
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 3
- Дата публикации:
- 1 июня 1978 г.
- Издание:
- ISO IS 5378 edition 1 version 1
- ICS:
- 67.180.20
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.
Abstract
Overview
ISO 5378:1978 specifies a spectrophotometric Kjeldahl method for determining nitrogen content in starches and derived products. The method is intended for samples with a presumed nitrogen content below 0.025% (m/m). It covers digestion (mineralization) with sulfuric acid and a compound catalyst, alkalization, distillation of released ammonia, collection in sulphuric acid, and spectrophotometric measurement of the resulting ammonium salt after addition of Nessler reagent (measurement at 430 nm).
Key topics and requirements
- Scope: Applicable to starches, flours and derivatives with N
Технические детали
- Технический комитет
- ISO/TC 93 - Starch (including derivatives and by-products)
- SKU
- ISO 5378:1978
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