Surface active agents - Determination of free alkalinity or free acidity - Titrimetric method English
1 Scope
This standard specifies a titrimetric method for the determination of free alkalinity or free acidity of surface active agents.
This method is applicable only if so indicated in the specific standard for each product.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this Standard. For dated references, subsequent amendments (excluding corrections) to, or revisions, of any of these publications do not apply to this standard. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the referenced document applies.
GB/T 6372 Surface active agents and detergents - Methods of sample division (GB/T 6372-2004, idt ISO 607:1980)
3 Terms and definitions
3.1
free alkalinity or free acidity
the alkalinity or acidity determined using phenolphthalein as indicator, expressed as the "alkali value" or the "acid value" as the case may be, i.e. in milligrams of potassium hydroxide present in 1 g of the product or required to neutralize 1 g of the product
4 Principle
Titration of an ethanolic or propanolic solution of the product with a standard volumetric potassium hydroxide or hydrochloric acid or sulphuric acid solution whichever is appropriate, in the presence of phenolphthalein as indicator.
5 Reagents
During the analysis, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity.
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents
6 Apparatus
7 Sampling
8 Procedure
9 Expression of results
10 Test report
