Measuring the purity of organic chemicals: general approaches and development of an appropriate procedure for research of pure organic chemicals

Pure materials are in demand in many sectors of the national economy, including the metrological service. High purity organic material is the ultimate source of metrological traceability in organic analysis to the basic units of the International System of Units (SI). This article presents the general approaches to determining the mass fraction of the main component in pure organic chemicals, which provide a traceable connection between the certified value of substance purity and the basic SI units - mass (kilogram) and amount of substance (mole), the features of using direct and indirect measurement approaches are considered, specific analytical methods that can be used for this purpose are discussed. Determining the purity of an organic material in most cases is not a plain analytical and metrological task. Solving this issue requires the relevant instrumental methods and appropriate measurement procedure, which is able to provide a comprehensive study of organic matter and guarantee the necessary accuracy of the certified value. Taking in consideration the vast diversity of organic chemicals, the determination of the purity of organic substances will never be a standardized procedure.