INDICATOR ELEMENT Russian patent published in 2022 - IPC G01N31/22 G01N33/22 

FIELD: chemical processes.

SUBSTANCE: present invention relates to an indicator element for determining the presence of emulsion, dissolved water and mechanical impurities in fluid fuels. Indicator element includes two layers of a polymer porous hydrophobic material with the ultrathin fibre structure - the first layer of the material is impregnated with a solution of iron (III) sulphate, the second layer is impregnated with a solution of a mixture of potassium hexacyanoferrate (III) and potassium hexacyanoferrate (II). Both layers are impregnated with solutions with the same solvent with the following ratio of components, vol.%: distilled water 45 to 55, ethyl alcohol 37 to 47, ethyl cellosolve 8 to 18, and dried. The concentration of iron (III) sulphate in the resulting solution during impregnation of the first layer is therein 0.5 to 5%, and the ratio of potassium hexacyanoferrate (III) and potassium hexacyanoferrate (II) to the solvent in the resulting solution during impregnation of the second layer is 1:(62.5 to 125).

EFFECT: increase in the reproducibility of the results of analysis, as well as accuracy of express analysis of fluid fuels.

4 cl, 1 tbl