METHOD FOR IDENTIFICATION OF AUTHENTICITY OF WINE

摘要

FIELD: chemistry.;SUBSTANCE: coulometric titration of 0.5-1.5 cm³ of wine in 50 cm³ of sodium chloride is carried out with generated OH^ˉ ions. A titration curve is plotted from the titration results and pH at the initial titration point is determined and the number of equivalents of H⁺ ions is calculated. pH discontinuity (equivalence point) is determined and the number of equivalents of H⁺ ions is calculated. The numerical value of the ratio of calculated number of equivalents found and if the numerical value lies in the 0.5±0.1 range, the wine is natural. The number of equivalents of H⁺ ions at the initial titration point and at the equivalence point is calculated using the following formulae: C=10^-pH·V_sol/V_v and C'= I·τ·1000/F·V_v, where V_sol is volume of the analysed solution in cm³; V_v is the volume of the wine sample in cm³; I is current in A; τ is time passed from the beginning of electrolysis to the equivalence point in s; F is the Faraday constant.;EFFECT: invention provides reliability of the method owing to the reduced effect of impurities and atmospheric carbon dioxide on the process of determining the number of equivalents of H⁺ ions in wine, and simplification of the process of authenticating wine owing to non-use of complex mathematical calculations.;5 dwg, 2 tbl, 3 ex