Development of Reference Materials of Ethanol Isotopic Composition

The research presented in the article is aimed at developing reference materials (hereinafter referred to as RMs) for the isotopic composition of ethanol required for measurements in accordance with the requirements of Russian standards and Technical Regulations of the Customs Union. The relevance is due to the expansion of the scope of isotope analysis in various fields, including the food industry, environmental monitoring and customs control. Current reference materials have a limited range of certified values and are not available in Russia due to the imposition of sanctions by unfriendly countries, which creates the need to develop domestic analogues. The purpose of the research is to create and subsequently certify the metrological characteristics of reference materials for the isotopic composition of ethanol obtained from various raw materials: corn, wheat, sugar beet and synthetic ethanol. For this purpose, a method for preparing reference materials was developed, a pilot batch was produced, tests for homogeneity, long-term and short-term stability were performed, and certified values of the isotopic composition of carbon, oxygen and hydrogen were determined. The main methods of RM production and certification included isotope mass spectrometry using the Isoprime precisION isotope mass spectrometer (hereinafter referred to as IMS), automated packaging and sealing of ampoules with reference materials. The study of metrological characteristics showed high homogeneity and stability of the developed reference materials, which confirms their suitability for metrological purposes. The certified values of the developed reference materials are consistent with known literature data on the isotopic composition of plant-based ethanol (corn and wheat), which confirms the reliability of isotopic analysis methods and their applicability for identifying biological sources of alcohol. The novelty of the research work lies in the development of domestic reference materials with a wider range of certified values of the isotopic composition of carbon, oxygen and hydrogen compared to analogues, which extends the capabilities of accurate measurements and control in various industries. The practical significance of the research is the development of new reference materials for quality control of alcoholic products, customs control and state control in the alcohol market. The developed reference materials provide accurate determination of the origin of ethanol, which is especially important for the identification of biological and synthetic sources. The research results create opportunities for developing reference materials of other substances, such as calcium carbonate, polyethylene and carbon monoxide.