InChI extension for mixture composition

InChI extension for mixture composition

Description:
This project proposes to encode chemical composition of mixtures within the IUPAC International Chemical Identifier (InChI). This innovation will extend the utility of the InChI as a general purpose identifier of chemicals and chemical systems beyond indexing by individual compounds. The ability to chemically describe all components in a given chemical system is desirable for a variety of purposes. Computer-readable representation of mixture composition could support data management pertaining to reaction planning, property calculation, anticipation of potential hazards, and process optimization. Such chemical information systems are already in development or planning stages, including electronic laboratory notebooks, chemical hazard and risk management procedures, and various data analysis applications. Enabling the InChI algorithm to be implemented at the process development stage will improve data linking and interoperability and establishes the best standard of practice up front.

In the context of developing safer and greener chemical management, additional information about concentration, purity, density and other issues related to mixtures becomes critical for planning and documentation. For common compounds with definitive core chemical structures, there may be multiple levels of purities manufactured and several variations of solutions stocked. Information systems that index by chemical structure will pool data across forms of the primary component without recourse for disambiguation. Other than the catalog numbers of chemical suppliers, no known publicly available identifier system exists that addresses these issues, and these identifiers suffer the same challenges as other internal record schemas. They are tied to functions of registration and record management and are not generally chemically meaningful outside of the original system, including the familiar and ubiquitous CAS Registry Number. These systems are not openly and globally scalable, transferable or computable.

The InChI system is particularly well designed to circumnavigate such limitations at the compound level through dynamic application of clearly defined property layers. Other InChI extension projects for representing salts, polymers and coordination compounds have set the stage for further consideration of multi-component scenarios. This project will scope the minimum additional information required to usefully specify chemical composition of the common types of mixtures used in laboratory research and address issues of terminology and units. The project is not intended to definitively capture all properties relevant to formulations.