Reference number
ISO 6840:1982
ISO 6840:1982
© ISO 2025
International Standard
ISO 6840:1982
Cationic surface active agents (Hydrochlorides and hydrobromides) — Determination of critical micellization concentration — Method by measurement of counter ion activity
Edition 1
1982-10
1982-10
ISO 6840:1982
13345
Published
(Edition 1, 1982)
This publication was last reviewed and confirmed in 2024.
Therefore this version remains current.
Abstract
The determination is carried out as follows: Potentiometric determination of the chloride or bromide ion activity of a series of solutions of cationic surface active agents the concentration of which cover the expected micellization concentration. Plotting the graph of potential as a function of the logarithm of the concentration; the c.m.c. corresponds to the singularity on this curve. The method is applicable to purified cationic surface active agents (hydrochlorides and/or hydrobromides), which are soluble in water and which have a Krafft temperature below 60 degree Celsius.