The standard describes a method for determining anionic surfactants (detergents) and other active substances with respect to Azur A, in drinking water, surface water and urban effluents and industrial. The method is applicable to waters whose active substance content with respect to Azur A is equal to or greater than 0.1 mg/1.
NBN T 91-504-1978 history
1978NBN T 91-504-1978 Water analysis methods - Determination of Azur A active substances