ISO 2272:1989 PDF
Surface active agents — Soaps — Determination of low contents of free glycerol by molecular absorption spectrometry
Surface active agents — Soaps — Determination of low contents of free glycerol by molecular absorption spectrometry
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 3
- Дата публикации:
- 29 июня 1989 г.
- Издание:
- ISO IS 2272 edition 2 version 1
- ICS:
- 71.100.40
The determination is carried out in the following way: Decomposition of the soap by sulfuric acid and extraction of the fatty acida with light petroleum. Oxidation of the free glycerol remaining in the aqueous phase by periodic acid to formic acid and formaldehyde. On reaction with chromotropic acid, the aldehyde formed gives an absorbing compound whose absorbance is propotional to the free glycerol content. Spectrometric measurement of the absorbance at a wavelength about 571 mm.
Abstract
Overview
ISO 2272:1989 specifies a spectrometric method for the determination of low contents of free glycerol in soaps. The technique uses molecular absorption spectrometry after chemical conversion of glycerol to a chromophore: soaps are decomposed by sulfuric acid, fatty acids are removed with petroleum ether, and free glycerol in the aqueous phase is oxidized by periodic acid to formaldehyde. Formaldehyde reacts with chromotropic acid to form an absorbing species measured at about 571 nm. The method is applicable to soaps with free glycerol content below 0.5% (w/w).
Key topics and technical requirements
- Scope: Intended for soaps with free glycerol
Технические детали
- Технический комитет
- ISO/TC 91 - Surface active agents
- SKU
- ISO 2272:1989
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