MT 173 - Colorimetric method for determination of the stability of dilute emulsions
Content Handbook F
Outline of method
A dye is dissolved in the emulsifiable concentrate formulation (EC). A sample of the dyed EC is added to a standard water to obtain an aqueous emulsion. At the end of a specified time an aliquot is withdrawn from the emulsion, and transferred to a flask to which propan-2-ol is added to clarify the emulsion. Then the absorbance of the dyed solution is measured in a spectrophotometer and compared to the
absorbance of a similar aliquot taken under the same conditions but at t0 (initial emulsion).
The method is suitable for determining the emulsion stability of dilute emulsions at dilution rates from 0.1 to 2.0%. Alternative conditions concerning standing times, volume of initial emulsion, may be fixed according to a given particular specification.