RU2568907C2 - Method of verification of authenticity of alcoholic drinks - Google Patents

Abstract

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

Description

The proposed technical solution relates to instrumental physicochemical methods for the study of alcohol-containing liquids, mainly alcoholic beverages, by directly comparing the characteristics of the identified and reference samples and is intended to establish the difference between genuine, falsified and counterfeit alcohol products.

The Unified State Automated Information System (EGAIS), currently operating in Russia, is intended for state control of the volume of production and turnover of alcoholic beverages and does not protect against the distribution of counterfeit and counterfeit products on the market, since it only takes into account the volumes of alcohol produced, supplied and sold. In this regard, an additional protection system is needed, based on the registration of the most typical and stable physical and chemical characteristics of products associated with its composition and membership in a particular manufacturer and a specific batch. The system should be based on cost-effective and affordable methods of analysis and modern information and analytical technologies that provide maximum automation of the identification process.

The current level of development of analytical chemistry allows the analysis of most complex objects using a variety of methods. The limiting factors are the high cost of testing, personnel potential and analysis time.

In the Russian Federation, there are currently established requirements for the quality of only some alcoholic beverages: cognac, fruit vodka, calvados and vodka. Based on the requirements of domestic standards GOST R 51618-2009 "Russian cognac. General technical conditions ”, GOST R 52135-2003“ Fruit vodkas. General technical conditions ”, GOST R 51300-99“ Russian Calvados. General technical conditions ”, it is impossible to identify counterfeit products, since the norms for varying indicators are set too wide. Vodka is a complex object for identification. The smaller variety of chemicals in the composition of vodka (compared with drinks made from grape raw materials) complicates its identification.

In Russia and abroad, many methods have been developed for assessing the quality and identification of alcoholic beverages: chromatographic, electrochemical, optical, isotopic, etc. (Belkin Yu.D., Polozhnikova MA.A review of modern methods for identifying cognacs and brandies used in domestic and foreign practice. // Commodity expert of food products No. 2, 2011). Most of them are either ineffective, or difficult to use, or extremely expensive, and therefore not widely used in the analysis and control of the food industry.

The method of gas-liquid chromatography allows you to very accurately identify alcohol products by the composition of various classes of chemical compounds, however, this analysis takes a lot of time, requires large material investments, highly qualified personnel, ensuring reproducible results (Savchuk S.A., Nuzhny V.P., Rozhanets V .V. Chemistry and toxicology of ethyl alcohol and drinks made on its basis: Chromatographic analysis of alcoholic beverages. M.: URSS, 2011).

The value of antioxidant activity cannot serve as a criterion for identification, since the addition of sugar tint to the majority of beverages obtained by distillation increases their antioxidant activity (E.V. Gorbunova. Study of the antioxidant capacity of red wines and the development of an algorithm for detecting their falsification: abstract of dissertation of the candidate of technical sciences : 05.18.15 - Moscow, 2012. - 22 p.), Which can become a source of simple and affordable falsification.

There is also known a method of analysis and / or identification of liquids based on the ability of microimpurities of liquids to luminesce (Patent RU N 2249811, IPC G01N 21/17, published. 04/10/2005). The method is intended to establish the authenticity of products by comparing the spectral and luminescent characteristics of the identified and reference products, which allows you to track the slightest changes in their composition. However, the implementation of this method requires the availability of expensive equipment.

In foreign practice, the following methods are known for obtaining and recognizing characteristic images of alcoholic beverages: recording and comparing spectra in the ultraviolet, visible, infrared near and middle regions, including using portable spectrophotometers (http://www.whisky-news.com /En/Report_authenticity.html); visible and near infrared spectroscopy in combination with multivariate analysis to classify the geographical origin of Spanish and Australian red wines based on Tempranillo grapes (J. Agr. and Food Chem. 2006. 54, No. 18, p. 6754-6759); system of quick "fingerprinting" to confirm the authenticity of wines by the method of infrared spectroscopy in the middle region (J. Ayr. and Food Chem. 2006. 54, Ns 26, pp. 9713-9718); methods of the main components and independent modeling by means of spectroscopy of ultraviolet and visible rays for the analysis of the studied data and the development of models for the classification of wines (Food Chem. 2006. 97, No. 1, 166-175); spectroscopy method in the ultraviolet and visible regions in combination with the reference vector method for classifying wines produced in certain regions (J. Agr. and Food Chem. 2007. 55, No. 17, p. 6842-6849); fast fingerprinting of red wines by mass spectrometry with desorption / ionization and the use of 2,5-dihydroxybenzoic acid as an optical matrix. (Anal. And Bioanal. Chem. 2007. 389, No. 3, 969-982); wine recognition based on the total composition of volatile compounds, recorded by a combination of solid-phase microextraction of equilibrium vapors and chromatography-mass spectrometry followed by data processing using analysis of the main components (J. Chromatogr. A. 2006. 1114, No. 2, 188-197); identification of the origin of brandy and other alcoholic beverages by the composition of carbon and oxygen isotopes (J. Science of Food and Agriculture, Volume 77, Issue 2, pp. 153-160, 1998). Thus, existing identification methods are either selective in type of beverage, or expensive, or too labor-consuming.

The prototype of the proposed method is a method for identifying the authenticity of alcohol-containing liquids, such as alcohols, vodkas, cognacs and wines (Patent RU N 2150699, IPC G01N 33/14, published. 06/10/2000), which is the basis for recommendations on standardization - R 50.1. 036-2002 “Recommendations for standardization. Vodka and vodka are special. Spectral-luminescent method for determining authenticity. "

The method provides for direct comparison of the full set of spectral and luminescent characteristics of the identifiable and reference liquids in the form of matrices that create the profile of the identifiable (A) and the reference sample (B), whose elements are: the values of the spectral transmittance of light at the wavelength of the incident radiation λ _i for identifiable and reference liquids scanning wavelength λ _i of the incident radiation between 200 and 750 nm and references to one intensity value in the spectrum of the luminescence identifiable and reference fluids at a wavelength λ _i when excited with light having a wavelength shift of wavelength λ _i λ _i exciting light of 200 to 750 nm and wavelength scanning registration λ _i from λ _i λ _i = 750 nm.

A sign of compliance of the identified and reference alcohol-containing liquids is compliance with the condition under which the difference matrix C = A-B = 0.

Despite the innovativeness of this method, it is still not widely used in the analytical practice of laboratories due to the high cost of the equipment necessary to implement the method.

The technical problem to be solved when developing the proposed method for identifying the authenticity of alcoholic beverages consists in creating an integrated instrumental method for identifying specific alcoholic beverages based on ultraviolet spectroscopy and conductometry with minimizing costs (material, time, etc.) while ensuring high reliability of the results and practical usability as manufacturers of alcoholic beverages, and regulatory authorities.

The technical result achieved by the implementation of the proposed method is the possibility of unambiguous identification of alcoholic beverages, reliable results of which allow us to establish the belonging of the test sample to a specific batch of alcohol of a particular producer and to detect the presence of counterfeit products. The advantages of the complex research method are also its simplicity of reproduction, low cost, clarity, objectivity and high accuracy of identification, which generally contributes to the widespread use of this method in analytical laboratories in various regions.

To solve this problem, a method for identifying the authenticity of alcoholic beverages was developed, based on the determination and subsequent comparison of the spectral characteristics of identifiable and reference samples. According to the proposed method, the selection of the comparable spectral characteristics of the studied samples is carried out within the informative region of their ultraviolet spectra, within which there is a distinct characteristic change in their recorded ultraviolet absorption spectra. Additionally, in the same samples of alcoholic beverages, the values of their electrical conductivity are measured and compared. The authenticity of the investigated products is established taking into account data obtained by two research methods: spectroscopic and conductometric. As a result of a comparative analysis of the totality of data from studies of identifiable and reference samples, authentic identify such identifiable products for which the subtraction curve within the boundaries of the informative region of the ultraviolet absorption spectra of the reference and identifiable samples meets the identification criteria A and B, determined from the following expressions taken modulo:

$$A=\left|\frac{{\displaystyle \sum _{i=\mathrm{one}}^n(({\lambda }_i-\overline{\lambda })\cdot (\Delta D_i-\overline{\Delta D}))}}{\sqrt{{\displaystyle \sum _{i=\mathrm{one}}^n{({\lambda }_i-\overline{\lambda })}^2}\cdot {\displaystyle \sum _{i=\mathrm{one}}^n{(\Delta D_i-\overline{\Delta D})}^2}}}\right|(\mathrm{one})$$

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

where λ _i ... λ _n - discrete values of the wavelengths of radiation within the informative region of the ultraviolet absorption spectra of the reference and identifiable samples, nm;

- среднее арифметическое из дискретных значений длин волн в границах информативной области ультрафиолетовых спектров поглощения эталонной и идентифицируемой проб, нм; $$\overline{\lambda }$$

- the arithmetic average of the discrete values of wavelengths within the informative region of the ultraviolet absorption spectra of the reference and identifiable samples, nm;

ΔD _i ... ΔD _n - discrete values of the optical density of the subtraction curve in the informative region of the ultraviolet absorption spectra of the reference and identifiable samples, e.o.s .;

- среднее арифметическое из дискретных значений оптической плотности кривой вычитания в информативной области ультрафиолетовых спектров поглощения эталонной и идентифицируемой проб, е.о.п.; $$\overline{\Delta D}$$

- the arithmetic average of the discrete values of the optical density of the subtraction curve in the informative region of the ultraviolet absorption spectra of the reference and identifiable samples, e.o.s .;

n is the number of discrete values of wavelengths λ _i ... λ _n , optical density ΔD _i ... ΔD _n the subtraction curve in the informative region of the ultraviolet absorption spectra of the reference and identifiable samples,

and accepting calculated values for colored alcoholic beverages A≥0.95, B≤1.0, for colorless alcoholic beverages B≤0.10, criterion A is not standardized. In this case, the measured value of the electrical conductivity of the identified and reference samples must satisfy the following inequality:

$$(\mathrm{one}-0.05E)\cdot S_i\le S_x\le (\mathrm{one}+0.05E)\cdot S_i,(3)$$

where S _i - the value of the electrical conductivity of the reference sample, µS / cm;

S _x - the value of the electrical conductivity of the identified samples, µS / cm;

E is the permissible value of the measurement error of the electrical conductivity,%.

Inequality (3) is obtained empirically. Criterion A, which characterizes the degree of linearity of the difference curve of the ultraviolet absorption spectra, is the modulo value of the Pearson linear correlation coefficient. Criterion B, which characterizes the variation in the values of the optical density of the curve for subtracting the ultraviolet absorption spectra in the informative region of the spectrum, is the modulus of the coefficient of variation for the values of the optical density ΔD _i ... ΔD _{n of the} curve for subtracting the indicated spectra.

Alcoholic beverages, as objects of study in the present method, are products from grape raw materials (cognac, brandy, armagnac, arbun, divin, Russian cognac, grappa, etc.), as well as vodka. A grape drink is a complex physicochemical system, often consisting of more than 700 components. Factors affecting the consumer properties and chemical composition of such products include the characteristics of the raw materials used (grape variety, technological properties of raw materials, wine material condition, physicochemical properties of water used in the production of sugar, color) and oak containers, aging periods of drinks, technological features of assembly and bottling. A smaller variety of chemicals in vodka (compared to drinks made from grape raw materials) complicates the identification.

The recorded ultraviolet absorption spectra of the samples under study, for the most part, make it easy to distinguish the alcohol production of various batches by the characteristic maxima and minima of the spectrum curve at certain wavelengths of light. In those cases when these spectra are indistinguishable, additional available information is required. As such additional information, according to the proposed method, the data of the conductometric research method are used, which makes it possible to unambiguously solve issues related to the identification of the test product. Electrical conductivity is a parameter that depends on a large number of factors, and at the same time it was chosen as an identifying indicator of the product belonging to a particular manufacturer. The main influence on the electrical conductivity in alcoholic beverages is exerted by the cationic anionic composition of the water used in production, and thus, the limits of variation in the electrical conductivity are characteristic for each manufacturer.

When recording spectra of alcoholic products in the ultraviolet and visible regions of the world, standard quartz cuvettes with a thickness of at least 1 mm are usually used. As a result of too strong absorption, the spectrum is not indicative - all the spectra of cognac and other alcoholic products (except vodka) are indistinguishable (the spectrum “rolls over”). In this regard, in the implementation of the method using collapsible cuvettes with quartz glasses used in IR spectroscopy. In this case, by varying the thickness of the gaskets between the glasses, spectra are obtained in the UV region with a measured absorption value.

The spectra of the studied samples of alcoholic beverages were recorded on a Shimadzu UV-2450 spectrophotometer. The electrical conductivity was measured on an Anion 4100 conductivity ionometer.

Parallel studies conducted on other equipment (SF-2000 spectrophotometer and EC-1382 conductivity meter) and with different time intervals (after 1 month for 6 months) show good reproducibility of the results with an error value of no more than 2%.

Using the proposed method investigated 124 samples of alcoholic beverages from grape raw materials and 47 samples of vodka simultaneously by two methods: UV spectroscopy and conductometry. The results obtained indicate good reproducibility of the results of such studies at different time intervals (after 1, 2, 3 months or more) for the same type of alcoholic beverage (the relative error does not exceed 2%).

The absorption spectra obtained for the most part make it easy to distinguish between alcoholic products of various parties. In the same cases when the spectra of samples of alcoholic products were quite close, which made their statistically significant distinction impossible, additional information is used - conductometry data, which allows us to unambiguously solve the problem of identification of the studied samples of alcoholic beverages.

Thus, for the first time, the possibilities were comprehensively used and the data of the above methods were interpreted based on obtaining reliable results of the study of alcohol products in order to establish its belonging to a specific batch of goods and the possibility of detecting falsified products was proved.

Figure 1 graphically shows the spectral curves in one coordinate system according to the ultraviolet absorption spectra on the wavelength interval 230-400 nm with a resolution of 1 nm for an identifiable sample of the first colored alcohol and the corresponding reference sample. Spectral curve 1 characterizes the identified sample of the first colored alcoholic beverage, curve 2 - its reference sample. Curve 3 is presented as the result of subtraction of curves 1 and 2 in the informative region of the recorded ultraviolet absorption spectra of these samples.

Figure 2 graphically shows the spectral curves in one coordinate system according to the ultraviolet absorption spectra on the wavelength interval 230-400 nm with a resolution of 1 nm for an identifiable sample of the second colored alcoholic beverage and the corresponding reference sample. Spectral curve 4 characterizes the identifiable sample of the second colored alcoholic beverage, curve 5 - its reference sample. Curve 6 is presented as the result of subtracting curves 1 and 2 in the informative region of the recorded ultraviolet absorption spectra of these samples.

Figure 3 graphically presents similar spectral curves obtained according to the ultraviolet absorption spectra on the wavelength interval 200-230 nm with a resolution of 1 nm for an identifiable sample of the first unpainted alcoholic beverage and the corresponding reference sample. Spectral curve 7 characterizes the identified sample of the first unpainted alcoholic beverage, curve 8 - its reference sample. Curve 9 is presented as the result of subtracting curves 7 and 8 in the informative region of the recorded ultraviolet absorption spectra of these samples.

Figure 4 graphically presents similar spectral curves obtained according to the ultraviolet absorption spectra on the wavelength range 200-230 nm with a resolution of 1 nm for an identifiable sample of the second unpainted alcoholic beverage and the corresponding reference sample. Spectral curve 10 characterizes the identifiable sample of the second unpainted alcoholic beverage, curve 11 - its reference sample. Curve 12 is presented as the result of subtracting curves 10 and 11 in the informative region of the recorded ultraviolet absorption spectra of these samples.

The table shows matrices of discrete values of the radiation wavelengths λ and optical density D of the subtraction curves 3, 6, 9, and 12 within the informative region of the ultraviolet absorption spectra of the reference and identifiable samples. The data in the table are used to construct curves 3, 6, 9 and 12, according to which the actual values of the identification criteria A and B are calculated.

The proposed method is as follows.

To establish the authenticity of the alcoholic beverage, the electrical conductivity of the identified and reference product samples is first measured taking into account the error of the conductivity meter used. Then, based on the obtained indicators of specific conductivity, a preliminary verification of the identifiable sample is carried out for authenticity by comparing these indicators for the identifiable and reference samples, using the inequality (3)

(1-0,05E) · S _i ≤S _x ≤ (1 + 0,05E) · S _i .

Having made sure that inequality (3) is observed for specific values of the specific conductivity of the reference sample S _i and the specific conductivity of the identified sample S _x , taking into account the permissible value of the measurement error of the specific conductivity E, we continue the further study of the analyzed product. To this end, the ultraviolet light absorption spectra of the identifiable and reference samples are recorded, then the characteristics of the identifiable and reference product samples are compared and the boundaries of the informative region of their ultraviolet absorption spectra are selected, within which a characteristic change in the recorded light absorption spectra is observed.

According to the ultraviolet absorption spectra on the selected segment of the wavelengths of light in one coordinate system graphically depict the spectral curves shown in figure 1. One of these curves, spectral curve 1, characterizes the identified sample taken for analysis of the alcoholic beverage, curve 2 corresponds to its reference sample. Curve 3 graphically reflects the resulting subtraction of curves 1 and 2 in the informative region of the recorded ultraviolet absorption spectra of these samples.

Using mathematical expressions (1) and (2), and matrices of discrete values of light wavelengths of the subtraction curve 3 within the boundaries of the informative region of the ultraviolet absorption spectra of the reference and identifiable samples given in the table, the actual values of the identification criteria A and B are calculated, according to which they : The test alcohol is genuine or counterfeit. At the same time, a colored alcoholic beverage for which criterion A≥0.95, criterion B≤1.0, or such a colorless alcoholic beverage for which criterion B≤0.1 (criterion A is not standardized) is recognized as authentic, and at the same time the measured values of the electrical conductivity of the identified and reference samples of a colored or colorless alcoholic beverage satisfy the inequality (3).

The following are specific examples of the implementation of the claimed method.

Example 1

To study the authenticity of the first colored alcoholic beverage, the specific electrical conductivity of its identifiable sample S _{x is} first measured, then the specific electrical conductivity of the reference sample of the Si alcoholic beverage in μS / cm. As a result of the measurements, S _x = 90 μS / cm, and S _i = 93 μS / cm. The permissible error in measuring the specific conductivity E for the used Anion 4120 conductivity meter is E = 2%. After that, according to the electrical conductivity of the identifiable and reference samples, when examining the first colored alcoholic beverage, the compliance with inequality (3) is checked, as a result of which it is calculated:

0.90 · 93≤90≤1.10 · 93;

83.70≤90≤102.3.

Thus, inequality (3) for the test sample is met, which allows the identifiable sample of the first colored alcoholic drink to be considered authentic in terms of electrical conductivity.

After that, the ultraviolet light absorption spectra of the identified and reference samples of the test first colored alcoholic beverage are recorded.

This example is illustrated in figure 1. The measurements are carried out in a quartz cuvette with an optical path length that ensures the recording of results over the entire wavelength segment with transmittance values not exceeding 1.50 e.p. Next, select the informative region of the ultraviolet absorption spectrum, in which characteristic changes in the spectra are observed, which corresponds to a wavelength range of 230-400 nm. Graphical spectral curves of the identifiable and reference samples are constructed in one coordinate system (Fig. 1) in the informative region of the spectrum (curves 1 and 2, respectively) and their subtraction curve 3 is also in the informative region of the spectrum. Using the matrix of discrete values of the subtraction curve 3 given in the table, the actual values of the identification criteria A and B are calculated using the above expressions (1) and (2):

n = 171

$$\overline{\lambda }=(230+231+232+...+400)/171=315$$

$$\overline{\Delta D}=((-0.138)+(-0.136)+(-0.133)+...+(-\mathrm{0,034}))/171=-\mathrm{0,072}$$

$$A=\left|\frac{\left(\left(230-315\right)\cdot \left(-0.138-\left(-\mathrm{0,072}\right)\right)+\left(231-315\right)\cdot \left(-0.136-\left(-\mathrm{0,072}\right)\right)+...+\left(400-315\right)\cdot \left(-\mathrm{0,034}-\left(-\mathrm{0,072}\right)\right)\right)}{\sqrt{\left[{\left(230-315\right)}^2+{\left(231-315\right)}^2+...+{\left(400-315\right)}^2\right]\cdot \left[{\left(-0.138-\left(-\mathrm{0,072}\right)\right)}^2+{\left(-0.136-\left(-\mathrm{0,072}\right)\right)}^2+...+\left(-\mathrm{0,034}-\left(-\mathrm{0,072}\right)\right)\right]}}\right|=0.98$$

$$B=\left|\frac{\sqrt{{(-0.138-(-\mathrm{0,072}))}^2+{(-0.136-(-\mathrm{0,072}))}^2+...+{(-\mathrm{0,034}-(-\mathrm{0,072}))}^2}}{(171\cdot (-\mathrm{0,072}))}\right|=0.39$$

Next, the identified sample is checked for compliance with the standard values of criteria A and B. Test result: A> 0.95; B <1.00

The subtraction curve 3 at the selected boundaries of the informative region of the ultraviolet absorption spectra of the reference and identifiable samples corresponds to the standard values of the identification criteria A and B. The test sample is identified with the reference and is genuine.

Example 2

A sample of the second colored alcoholic beverage is examined to determine its authenticity. An example is illustrated in FIG. The measured conductivity of the identified and reference samples in μS / cm, respectively, is S _x = 40 μS / cm and S _i = 37 μS / cm. The measurement error, according to the documentation for the ECTester 138 (II) conductivity meter used for measurement, E = 2%. Verification of the identifiable sample for authenticity in terms of electrical conductivity using expression (3) reveals:

0.90 · 37≤40≤1.10 · 37;

33.30≤40≤40.70.

As a result of the above calculation, it can be concluded that inequality (3) is observed, and according to the electrical conductivity index, the identified sample is presumably true.

The conclusion made is clarified by continuing further research of the samples by recording the ultraviolet absorption spectra of the identifiable and reference samples of the second colored alcoholic beverage at a wavelength interval of 200-400 nm with a resolution of 1 nm. The measurements are carried out in a quartz cuvette with an optical path length that ensures the recording of results over the entire wavelength segment with transmittance values not exceeding 1.50 e.p. Next, select the informative region of the ultraviolet absorption spectrum, in which characteristic changes in the spectra are observed, which corresponds to a segment of 230-400 nm. Build in one coordinate system, as shown in figure 2, the spectral curves of the identifiable sample (curve 4), the reference sample (curve 5) and the curve of their subtraction (curve 6) in the informative region of the spectrum 230-400 nm.

$$\overline{\Delta D}=-\mathrm{0,012};$$

критерий A=0,58; критерий B=1,09.Using the matrix of discrete values of curve 6 in the table, the actual values of the identification criteria A and B are calculated by analogy with the calculations presented in Example 1. The results of the calculations are as follows: n = 171; $$\overline{\lambda }=315;$$

$$\overline{\Delta D}=-0.012;$$

criterion A = 0.58; Criterion B = 1.09.

Next, the identified sample is checked for compliance with the regulatory values of the identification criteria A and B. The result: A <0.95; B> 1.00. Identification criteria A and B do not correspond to their normative values. Therefore, the test sample, the second colored alcoholic beverage, cannot be identified with the standard and is falsified.

Example 3

The sample of the first colorless alcoholic beverage is being investigated. The measured value of the electrical conductivity of the identified sample is S _x = 2 μS / cm, and the reference sample is S _i = 2 μS / cm. The measurement error of the used Anion 4120 conductivity meter E = 2%. Verification of the identifiable sample for authenticity in terms of electrical conductivity in accordance with expression (3) shows:

0.90 · 2≤2≤1.10 · 2;

1.80≤2≤2.20.

Therefore, the inequality of expression (3) is satisfied. In terms of electrical conductivity, the identifiable sample of the first colorless alcoholic beverage is presumably genuine.

Next, the ultraviolet absorption spectra of the identified and reference samples are recorded on a wavelength interval of 200-400 nm with a resolution of 1 nm. This example is illustrated in figure 3. Studies are carried out in compliance with the conditions described in examples 1, 2. The informative region of the spectrum is selected at a wavelength range of 200-230 nm. In one coordinate system (Fig. 3), the spectral curves of the identifiable and reference samples (curves 7 and 8, respectively) are constructed and the curve of their subtraction (curve 9) in the informative region of the spectrum.

$$\overline{\Delta D}=-\mathrm{0,026};$$

критерий идентификации B=0,06. По полученным данным проверяют идентифицируемую пробу на соответствие нормативным значениям критерия идентификации В для первого бесцветного спиртного напитка: критерий B<0,1, следовательно, исследуемая проба идентифицирована с эталоном и является подлинной.Using the matrix of discrete values of curve 9 shown in the table, the actual value of identification criterion B is calculated, by analogy with the calculations shown in example 1, according to which the following data are obtained: n = 31; $$\overline{\lambda }=115;$$

$$\overline{\Delta D}=-\mathrm{0,026};$$

identification criterion B = 0.06. According to the data obtained, the identifiable sample is checked for compliance with the standard values of the identification criterion B for the first colorless alcoholic beverage: criterion B <0.1, therefore, the test sample is identified with the standard and is genuine.

Example 4

The sample of the second colorless alcoholic beverage is studied, for which the measured value of the specific conductivity of the identified sample is S _x = 12 μS / cm, of the reference sample - S _i = 12 μS / cm. The measurement error of the used conductivity meter ECTester 138 (II) E = 2%. The identifiable sample is checked for authenticity by the conductivity index using expression (3), according to which:

0.90 · 12≤12≤1.10 · 12;

10.8≤12≤22.0.

According to the electrical conductivity, inequality (3) is observed, therefore, the identifiable sample of the second colorless alcoholic beverage is, presumably, genuine. The study is continued according to the registration of ultraviolet absorption spectra of the identified and reference samples at a wavelength interval of 200-400 nm with a resolution of 1 nm. The measurements are carried out under similar conditions described in examples 1-3. The informative region of the ultraviolet absorption spectrum is selected, in which the most characteristic changes in the spectra of the studied samples are observed over a wavelength range of 200-230 nm. An example is illustrated in FIG. In one coordinate system, spectral curves are constructed in the informative region of the spectrum of the identifiable sample (curve 10), the reference sample (curve 11) and the curve of their subtraction (curve 12).

$$\overline{\Delta D}=\mathrm{0,018};$$

критерий B=0,34.Using the matrix of discrete values of curve 12 shown in the table, the actual value of the identification criterion B is calculated by analogy with the calculations made in example 1. The following calculation results are obtained: n = 31; $$\overline{\lambda }=115;$$

$$\overline{\Delta D}=0.018;$$

criterion B = 0.34.

Next, the identifiable sample is checked for compliance with the normative values of identification criterion B for the second colorless alcoholic beverage. Since B> 0.10, inequality (3) is not satisfied, therefore, the test sample of the second colorless alcoholic drink cannot be identified with the standard and is falsified.

Table Example 1 Example 2 Example 3 Example 4 λ, nm ΔD, e.p. λ, nm ΔD, e.p. λ, nm ΔD, e.p. λ, nm ΔD, e.p. one 2 3 four 5 6 7 8 230 -0.138 230 -0.049 200 -0.036 200 0,029 231 -0.136 231 -0.047 201 -0.033 201 0,027 232 -0.133 232 -0.046 202 -0.034 202 0,026 233 -0.132 233 -0.046 203 -0.035 203 0,025 234 -0.131 234 -0.045 204 -0.035 204 0,023 235 -0.129 235 -0.044 205 -0.033 205 0,023 236 -0.127 236 -0.044 206 -0.033 206 0,023 237 -0.126 238 -0.043 207 -0.032 207 0,023 238 -0.124 238 -0.043 208 -0.032 208 0,023 239 -0.123 239 -0.042 209 -0.031 209 0,023 240 -0.120 240 -0.042 210 -0.030 210 0,022 241 -0.119 241 -0.041 211 -0.029 211 0,022 242 -0.118 242 -0.041 212 -0.028 212 0,021 243 -0.116 243 -0.040 213 -0.028 213 0,020 244 -0.116 244 -0.040 214 -0.027 214 0.019 245 -0.114 245 -0.039 215 -0.026 215 0.018 246 -0.112 246 -0.039 216 -0.025 216 0.017 247 -0.111 247 -0.038 217 -0.024 217 0.016 248 -0.109 248 -0.038 218 -0.023 218 0.016 249 -0.108 249 -0.036 219 -0.023 219 0.014 250 -0.107 250 -0.035 220 -0.022 220 0.014 251 -0.107 251 -0.035 221 -0.021 221 0.014 252 -0.104 252 -0.034 222 -0.021 222 0.012 253 -0.104 253 -0.033 223 -0.020 223 0.012 254 -0.102 254 -0.032 224 -0.020 224 0.012 255 -0.102 255 -0.031 225 -0.020 225 0.011 256 -0.102 256 -0.029 226 -0.019 226 0.011 257 -0,100 257 -0.028 227 -0.019 227 0.010 258 0,099 258 -0.027 228 -0.019 228 0.009 259 0,099 259 -0.025 229 -0.019 229 0.009 260 -0.098 260 -0.024 230 -0.018 230 0.008 261 -0.098 261 -0.023 262 -0.098 262 -0.021 263 -0.097 263 -0.020 264 -0.097 264 -0.018 265 -0.096 265 -0.016 266 -0.096 266 -0.015 267 -0.096 267 -0.014 268 -0.095 268 -0.012 269 -0.095 269 -0.011 270 -0.095 270 -0.009 271 -0.094 271 -0.007 272 -0,093 272 -0.006 273 -0.094 273 -0.005 274 -0,093 274 -0.003 275 -0,093 275 -0.002 276 -0.092 276 0,000 277 -0.092 277 0.001 278 -0.091 278 0.002 279 -0.090 279 0.003 280 -0.090 280 0.004 281 -0.089 281 0.004 282 -0.090 282 0.005 283 -0.089 283 0.006 284 -0.088 284 0.006 285 -0.087 285 0.006 286 -0.086 286 0.007 287 -0.085 287 0.007 288 -0.085 288 0.006 289 -0.084 289 0.006 290 -0.083 290 0.005 291 -0.082 291 0.005 292 -0.081 292 0.004 293 -0.082 293 0.004 294 -0.080 294 0.003 295 -0.079 295 0.002 296 -0.078 296 0.001 297 -0.078 297 0,000 298 -0.077 298 -0.001 299 -0.076 299 -0.002 300 -0.077 300 -0.004 301 -0.075 301 -0.004 302 -0.075 302 -0.005 303 -0.074 303 -0.007 304 0,075 304 -0.007 305 0,073 305 -0.008 306 0,072 306 -0.008 307 0,073 307 -0.009 308 0,072 308 -0.009 309 0,072 309 -0.010 310 0,070 310 -0.010 311 0,070 311 -0.010 312 0,069 312 -0.010 313 0,068 313 -0.011 314 0,069 314 -0.010 315 0,069 315 -0.012 316 0,067 316 -0.011 317 0,067 317 -0.012 318 0,067 318 -0.011 319 0,066 319 -0.011 320 0,066 320 -0.011 321 0,066 321 -0.011 322 0,064 322 -0.011 323 0,063 323 -0.011 324 0,063 324 -0.011 325 0,062 325 -0.011 326 0,062 326 -0.011 327 0,061 327 -0.011 328 0,061 328 -0.010 329 0,060 329 -0.011 330 0.059 330 -0.010 331 0.059 331 -0.011 332 0,057 332 -0.010 333 0,057 333 -0.010 334 0,057 334 -0.011 335 0,057 335 -0.010 336 0.056 336 -0.009 337 0,055 337 -0.010 338 0,055 338 -0.009 339 0,055 339 -0.009 340 0,054 340 -0.009 341 0,053 341 -0.010 342 0,052 342 -0.009 343 0.051 343 -0.009 344 0.051 344 -0.009 345 0,050 345 -0.008 346 0,050 346 -0.009 347 0,049 347 -0.009 348 0,049 348 -0.009 349 0,048 349 -0.009 350 0,049 350 -0.008 351 0,048 351 -0.009 352 0,048 352 -0.009 353 -0.047 353 -0.008 354 -0.046 354 -0.009 355 -0.047 355 -0.009 356 -0.045 356 -0.009 357 -0.045 357 -0.008 358 -0.045 358 -0.008 359 -0.044 359 -0.009 360 -0.044 360 -0.008 361 -0.045 361 -0.008 362 -0.045 362 -0.009 363 -0.045 363 -0.008 364 -0.044 364 -0.008 365 -0.044 365 -0.008 366 -0.043 366 -0.007 367 -0.043 367 -0.007 368 -0.043 368 -0.008 369 -0.042 369 -0.007 370 -0.043 370 -0.008 371 -0.042 371 -0.007 372 0,041 372 -0.007 373 0,041 373 -0.007 374 0,041 374 -0.007 375 0,041 375 -0.007 376 0,041 376 -0.007 377 0,040 377 -0.007 378 0,040 378 -0.006 379 0,040 379 -0.007 380 0,039 380 -0.006 381 0,040 381 -0.006 382 0,039 382 -0.006 383 0,039 383 -0.006 384 0,038 384 -0.006 385 0,038 385 -0.006 386 0,039 386 -0.006 387 0,038 387 -0.006 388 0,037 388 -0.006 389 0,037 389 -0.005 390 0,037 390 -0.006 391 0,037 391 -0.005 392 0,037 392 -0.005 393 0,037 393 -0.005 394 0,036 394 -0.005 395 0,036 395 -0.005 396 0,036 396 -0.005 397 0,036 397 -0.005 398 0,035 398 -0.005 399 0,035 399 -0.005 400 0,034 400 -0.005

Claims (1)

A method for identifying the authenticity of alcoholic beverages, which includes measuring the electrical conductivity of an identifiable and reference sample and conducting a preliminary verification of the identifiable sample for authenticity by comparing these indicators for both samples using the inequality:

where S _i - the value of the electrical conductivity of the reference sample, µS / cm;
S _x - the value of the electrical conductivity of the identified samples, µS / cm;
E is the permissible value of the measurement error of the electrical conductivity,%.
subject to this inequality, the ultraviolet absorption spectra of the identifiable and reference samples of the alcoholic beverage are recorded, graphical spectral curves of the indicated samples and their subtraction curve are plotted in the informative region of the spectrum, which is 230-400 nm for colored alcoholic drinks and 200 for unpainted alcoholic ones -230 nm, the actual values of the identification criteria A and B are calculated from the matrix of discrete values of the subtraction curve, after which such an identifiable product is recognized as genuine for which the subtraction curve within the informative region of the ultraviolet absorption spectra of the reference and identifiable samples corresponds to the specified criteria determined from the following expressions:

where λ _i ... λ _n - discrete values of the wavelengths of radiation within the informative region of the ultraviolet absorption spectra of the reference and identifiable samples, nm;

- the arithmetic average of the discrete values of wavelengths within the informative region of the ultraviolet absorption spectra of the reference and identifiable samples, nm;
ΔD _i ... ΔD _n - discrete values of the optical density of the subtraction curve in the informative region of the ultraviolet absorption spectra of the reference and identifiable samples, e.o.s .;

- the arithmetic average of the discrete values of the optical density of the subtraction curve in the informative region of the ultraviolet absorption spectra of the reference and identifiable samples, e.o.s .;
n is the number of discrete values of wavelengths λ _i ... λ _n , optical density ΔD _i ... ΔD _n the subtraction curve in the informative region of the ultraviolet absorption spectra of the reference and identifiable samples,
and accepting calculated values for colored alcoholic beverages A≥0.95, B≤1.0; for colorless spirits B≤0.10.

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