Test methods of soaps
Determination of chloride content in soaps - Titrimetric method
1 Scope
This standard specifies a method for determining the chloride content in soaps.
This standard is applicable to soaps having chloride content, expressed as sodium chloride, equal to or greater than 0.1 %.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard.
For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For any undated references, the latest edition of the document referred to applies.
GB/T 603 - 2002 Chemical reagent - Preparations of reagent solutions for use in test methods
QB/T 2623.1 - 2003 Test methods of soaps - Determination of free caustic alkali content in soaps
3 Test methods
Unless otherwise specified, during the analysis, use only reagents of recognized analytical reagent quality and only distilled water or water of at least equivalent purity.
3.1 Principle
Determination of the chloride content by argentimetric titration after decomposition of a test portion and separation of fatty acids by filtration.
3.2 Reagents and materials
a) Nitric acid (GB/T 626), which shall be boiled until colourless if it turns yellow.
b) Ammonium iron (III) sulfate (GB/T 1279), 80g/L solution, prepared according to 4.1.4.25 of GB/T 603 - 2002.
c) Ammonium thiocyanate (GB/T 660), standard volumetric solution, c(NH4SCN)＝0.1mol/L.
d) Silver nitrate, (GB/T 670), standard volumetric solution, c(AgNO3)＝0.1mol/L.
3.3 Apparatus
Foreword I
1 Scope
2 Normative references
3 Test methods
