Melting Point Certified Reference Materials for Organic Substances: Development Prospects

Measurements of the melting point of high-purity organic substances are crucial in various fields, such as medicine, biology, and perfumery and cosmetic production. This research was aimed at developing melting point certified reference materials (CRMs) for organic substances, with metrological traceability to the SI base units for “temperature” (°C). The study analyzes the metrological assurance in the field of melting point measurements, including a reference complex used to measure the melting point and purity of organic substances in the range of + 40 to + 250 °C. The research also identifies the basic requirements for substances eligible as CRMs. The study presents the results of determining the melting point of benzophenone, benzoic acid, succinic acid, anthracene, and caffeine, along with interlaboratory comparisons. To harmonize the results, a method is suggested, which involves presenting the certified value of the melting point determined by direct measurements and certified values of the optical transparency temperature at various heating rates in the certificates of the developed CRMs. These results have theoretical significance in improving the accuracy of measurements in the field of thermal analysis to a higher quality level. The study also outlines research directions for future work.