PROCESS OF DETERMINATION OF CONTENT OF ETHANOL IN COMPLEX WATER-AND-ALCOHOL SOLUTIONS Russian patent published in 1996 - IPC

FIELD: analytical chemistry. SUBSTANCE: invention refers to instrumental analysis and can also find use in food industry, namely in wine-making. Invention makes it possible to find content of ethanol in complex water-and-alcohol solutions independent of composition and quantities of carried impurities within wide interval of concentration. Process includes preparation of three samples, two of them differ by content of ethanol from content of ethanol in examined solution. Salt of quaternary ammonium base and aqueous solution of sodium chloride are added to concentration 20 g/1. Values of potential of ion-selective electrode reversible to cations of quaternary ammonium base are measured and content of ethanol is computed by formula: , where C_x is content of ethanol in analyzed sample, C is content of ethanol in standard water-and-ethanol solution; V_o is volume of sample of analyzed solution; V_s is volume of additive of standard water-and-ethanol solution; V_w is volume of additive of water; E₁ is potential of electrode in sample of analyzed solution without additive; E₂ is potential of electrode in sample with additive of standard water-and-ethanol solution; E₃ is potential of electrode in sample with additive of water. EFFECT: increased authenticity of analysis. 1 dwg