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ISO 4274:1977
© ISO 2024
ISO 4274:1977
Urea for industrial use — Determination of biuret content — Flame atomic absorption and photometric absorption methods
Версия 1
1977-10
В время отменен
Отозвано (Версия 1, 1977)

Тезис

Applicable to products having contents of equal to or more than 0.05 % (m/m) (with flame atomic absorption) or 0.1 % (m/m) (with fotometric absorption). Covers the formation of a complex between biuret and copper(II) sulphate in alkaline medium. Fixation of this complex on an anion exchange resin. Elution of Cu first with a potassium nitrate solution and then with a nitric acid solution. Flame atomic absorption: aspiration of the solution into an acetylene-air flame and measurement of the absorption of the 325-nm line emitted by a copper hollow-cathode lamp; or by photometric absorption: formation of a coloured complex between Cu and zinc dibenzyldithiocarbamate, extraction with carbon tetrachloride and measurement at a wavelength of about 435 nm. Has also been approved by the IUPAC.

Общая информация

  • Текущий статус
     : Отозвано
    Дата публикации
     : 1977-10
    Этап
    : Отмена международного стандарта [95.99]
  • Версия
     : 1
  • Технический комитет :
    ISO/TC 47
    ICS :
    71.080.30 
  • RSS обновления

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  2. Интернет-магазин
  3. Каталог стандартов
  4. МКС
  5. 71
  6. 71.080
  7. 71.080.30
  8. ISO 4274:1977