2025-11-17 A method for the quantitative determination of volatile compounds in alcoholic beverages from grapes or other plant materials using ethanol as an internal standard ("IS_Ethanol") was first proposed in 2013 [1]. Its essence lies in the use of ethanol contained in the sample as an internal standard in order to improve the accuracy of measurements and eliminate the need for adding an internal standard. The advantages of this method (modified internal standard method, hereinafter referred to as "IS_Ethanol") include, in particular, the elimination of the need to measure the density and strength of the analyzed sample: the concentration of volatile impurities is calculated based on measurements directly in units of g/100 L of anhydrous alcohol (g/100 L AA) or mg/L of anhydrous alcohol (mg/L AA). This method is suitable for the determination of a number of volatile substances such as acetaldehyde (ethanal), methyl acetate, ethyl acetate, 1,1-diethoxyethane (acetal), methanol, butan-2-ol, propan-2-ol, propan-1-ol (n-propanol), isobutanol (2-methylpropan-1-ol), butan-1-ol (n-butanol), active amyl alcohol (2-methylbutan-1-ol), isoamylol (3-methylbutan-1-ol) with an analyte content of 0.2-1500 g/100L AA or 2-15000 mg/L AA in alcoholic and other alcohol-containing products by gas chromatography. Since 2013, the new "IS_Ethanol" method has undergone extensive testing on a wide range of alcoholic beverages and alcohol-containing products. Validation of the "IS_Ethanol" method for alcoholic beverages was carried out within a single laboratory [2]. Then, interlaboratory studies [3], [4] were conducted. The developed "IS_Ethanol" method was tested on various compounds, demonstrating improved detection and quantification limits compared to current official methods [5], [6], [7], [8a], [8b], [9a], [9b].
The new "IS_Ethanol" method has the following advantages:
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It is important to note that the new "IS_Ethanol" method can be validated in any laboratory testing alcoholic beverages, based on archival data previously obtained using current standards. When determining the quantitative content of volatile compounds in alcoholic beverages, all modern gas chromatographs equipped with a FID and a capillary column with a polar phase detect an ethanol peak. Consequently, the chromatograms of calibration mixtures and alcoholic beverage samples always show an ethyl alcohol peak alongside the peaks of volatile compounds. Millions of liters of alcoholic beverages are produced worldwide every day. Before shipping to consumers, all alcoholic beverages undergo mandatory testing for the quantitative content of volatile compounds, particularly methyl alcohol. Consequently, thousands of such official gas chromatographic determinations of the quantitative content of volatile components in alcoholic beverages are conducted daily worldwide. Following the publication of a detailed description of the proposed "IS_Ethanol" method in 2013 [1], no comments regarding its lower efficiency compared to the traditional internal standard method have emerged. In the Russian Federation, the "Methodology for measuring the mass concentration of aldehydes, esters, methyl alcohol, and higher alcohols in alcohol-containing products using gas chromatography" method has been certified in accordance with the requirements of the national standard of the Russian Federation GOST R "State System for Ensuring the Uniformity of Measurements. Measurement Methods."
Any testing laboratory that determines the quantitative content of volatile compounds in alcoholic beverages can independently verify that the efficiency and metrological characteristics of the proposed "IS_Ethanol" method are not lower than the efficiency and metrological characteristics of the official testing methods used. A detailed description of such a validation algorithm was presented in an oral report at the 46th Congress of the International Intergovernmental Organization of Wine and Vine (OIV, 16-20 June 2025, Chisinau, Moldova) link 1 and published [8].
This circumstance opens the possibility of collecting a sufficiently large number of official method validation reports from various testing laboratories around the world without significant financial outlay. Obtaining a sufficiently large number of official method validation reports from various laboratories will allow the OIV SCMA to substantiate its decision to recognize OENO-SCMA Project 24-756, "Method for the Determination of Volatile Compounds in Alcoholic Beverages of Grape Origin Using the Ethanol Contained Therein as a Reference Substance."
Literature : Below you can find the amended texts of official methods in force in various countries, allowing for the analysis of alcoholic beverages using the new developed "IS_Ethanol" method. Fragments in the document to be deleted are highlighted in yellow. Inline fragments of the new method are highlighted in green. Data to be established based on the results of interlaboratory studies is highlighted in blue. [10-12] National Standards of China (with proposed modifications)
[13] National Standard of India (with proposed modifications)
[14] National Standard of Mexico (with proposed modifications)
[15] European Union Regulation ЕС2870/2000 (с предлагаемыми модификациями)
[16-18] OIV methods (with proposed modifications)
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