FIELD: determination of anion surface-active substances in milk, juices, any soft and alcoholic drinks. SUBSTANCE: indicatororganic fluorescent pigment containing quaternary atom of nitrogen or mixture of strong inorganic acid with organic fluorescent pigment carrying amino and/or alkylamino group is injected into examined sample, polyphosphate buffer having high ionic force and pH=2.0-5.0 is added. Obtained compounds colored by organic solvent are extracted, intensity of its fluorescence and/or coloring is measured and its value is used to evaluate content of anion surface-active substance. EFFECT: widened range of types of analyzed solutions, reduced detection threshold, increased accuracy of detection. 12 cl
