Measuring the purity of organic substances: general approaches and development of an optimal procedure for studying pure organic materials

Pure materials are in demand in many sectors of the national economy, science, and industry, including for the solution of metrological challenges in the field of organic synthesis, where pure organic substances are the basis for forming a chain of metrological traceability to the International System of Units (SI). This article analyzes the internationally recognized approaches to measuring purity of pure organic substances that ensure traceability of the certified values of material purity to the basic SI units, such as a mole and a kilogram. The article also discusses the specifics of using direct and indirect methods for measuring purity of organic substances, as well as specific analytical techniques and procedures that can be used for this purpose. It was emphasized that determining the purity of an organic material in most cases is not a simple analytical and metrological task. It requires relevant instrumental methods and optimal measurement procedure, based on such methods, to guarantee a comprehensive study of the organic substance and ensure the necessary accuracy of the certified characteristic value. It was pointed out that due to the vast diversity of organic compounds, determining material purity will never be a standardized procedure.