METHOD OF VERIFICATION OF AUTHENTICITY OF ALCOHOLIC DRINKS Russian patent published in 2015 - IPC G01N33/14 G01N21/17 G01N27/06 

FIELD: measurement equipment.

SUBSTANCE: invention relates to instrumentation physical and chemical methods of study of alcohol-containing liquids, mainly alcoholic drinks and is intended for identification of distinction between a true, adulterate and counterfeit alcoholic products. The method envisions the measurement of specific conductivity of identifiable and reference samples and performing of preliminary check of the identifiable sample for authenticity by comparison of these parameters for both tests using the inequation: (1-0.05E)·S_i ≤ S_x ≤(1+0.05E)·S_i, where S_i - the value of specific conductivity of the reference sample, mcSm/cm; S_x - the value of specific conductivity of the identifiable sample, mcSm/cm; E - allowable value of an error of measurement of specific conductivity, %. At compliance with this inequality the ultra-violet spectra of absorption of the identifiable and reference samples of alcoholic drink are registered, in the same coordinate system the graphic spectral curves of the named samples and the curve of their subtraction in the informative area of the spectra are plotted, and for the coloured alcoholic drinks it amounts 230-400 nanometres, and for the uncoloured ones - 200-230 nanometres, using the matrix of discrete values of the subtraction curve the actual values of criteria of identification of A and B are calculated, after that the true one is recognised such identifiable product for which the subtraction curve within the informative area of ultra-violet spectra of absorption of the reference and identifiable samples corresponds to the named criteria determined from the following expressions: $$A=\left|\frac{{\displaystyle \sum _{i=1}^n(({\lambda }_i-\overline{\lambda })\cdot (\Delta D_i-\overline{\Delta D}))}}{\sqrt{{\displaystyle \sum _{i=1}^n{({\lambda }_i-\overline{\lambda })}^2}\cdot {\displaystyle \sum _{i=1}^n{(\Delta D_i-\overline{\Delta D})}^2}}}\right|(1)$$

$$B=\left|\frac{\sqrt{{\displaystyle \sum _{i=1}^n{(\Delta D_i-\overline{\Delta D})}^2}}}{(n\cdot \overline{\Delta D})}\right|\text{, }(2)$$

where λ_i…λ_n - discrete values of lengths of waves of radiation within the informative area of ultra-violet spectra of absorption of the reference and identifiable samples, nanometres; $$\overline{\lambda }$$ - an arithmetic average of discrete values of lengths of waves within the informative area of ultra-violet spectra of absorption of the reference and identifiable samples, nanometres; ΔD_i…ΔD_n - discrete values of optical density of the curve of subtraction in the informative area of ultra-violet spectra of absorption of the reference and identifiable samples, optical density units; $$\overline{\Delta D}$$ - an arithmetic average of discrete values of optical density of a curve of subtraction in informative area of ultra-violet ranges of absorption of the reference and identifiable samples, optical density units; n - number of discrete values of lengths of waves λ_i…λ_n, optical density of ΔD_i…ΔD_n of the curve of subtraction in the informative area of ultra-violet spectra of absorption of the reference and identifiable samples, and accepting calculated values for the coloured alcoholic drinks A≥0.95, B≤1.0; for uncoloured alcoholic drinks B≤0.10.

EFFECT: improvement of veracity and reliability, and also - high precision of identification is achieved.

4 dwg, 1 tbl, 4 ex