Разработка рефрактоденсиметрического метода определения содержания этилового спирта и общего экстракта вин на ЭВМ

Abstract

The work is devoted to the improvement of the methodological foundations of the refractodensimetric method of analysis as applied to liquid alcohol-containing products of grape winemaking. The regularities of changes in density and specific refraction of ethyl alcohol and substances of the extract of grapes and wine depending on their concentration based on the processing of the data of measuring the refractive index and density of various alcohol-containing products of winemaking and model solutions based on them, as well as based on the analysis of data from official densimetric and refractometric tables to determine the concentration of aqueous solutions of ethyl alcohol and total extract of the must, has been determined. The improved mathematical model of an alcoholic drink is proposed, which adequately describes the dependence of the refractive index and density of the drink on the content of ethyl alcohol and extract, based on the use of the additivity property of the specific refraction and the mass of the components of its constituents. On the basis of the proposed mathematical model of the drink, an algorithm has been developed for determining the volume fraction of ethyl alcohol and the mass concentration of the total extract for winemaking products, based on measuring the density and refractive index as the basis for the method for determining the volume fraction of ethyl alcohol and the mass concentration of the total extract. Preliminary metrological certification of the method for determining the mass concentration of the total extract and the volume fraction of ethyl alcohol in alcohol-containing products of grape winemaking has been carried out. The results of the work can be the basis for the development of a non-destructive express method for determining the volume fraction of ethyl alcohol and the mass concentration of the total extract based on the standard equipment of the laboratory of wineries, as well as the development of technical specifications for the manufacture of a portable device for determining the concentration of alcohol and extract based on the simultaneous measurement of the refractive index and density of liquid media.