Mixtures InChI: MInChI

Working Group Chair:  Leah McEwen

Working group: Alex Clark, Antony Davies, John Duffus, Chris Jakober, Jon LaRue, Gerd Blank, Richard Hartshorn, Andrey Yerin


All chemicals exist as mixtures in practice, and mixed substances represent a significant fraction of chemical catalogs and laboratory stocks. Chemical composition impacts reactivity, unintentionally or designed. Communicating information about composition is critical for conducting safe, effective, and scientifically meaningful chemistry and other laboratory functions. There is a practical need to connect data and information on mixtures with individual components and process design factors to facilitate analysis on properties, composition, etc. The IUPAC MInChI project (2015-025-4-800) describes a method to apply the IUPAC InChI identifier to describe what is definitively known about the chemical composition of a given mixed substance, generating an unambiguous machine-readable linear notation for mixed substances of uniform properties that can resolve to unique components.

The MInChI notation is tailored for a primary use case to describe what is definitively reported for source components at the time of mixing. The initial phase is focused on components with molecular structures that produce a well defined standard InChI identifier. Separate, discrete components allows for easy association of arbitrary concentrations. Other types of components may be considered for future phases of the project. While the core InChI identifier lends some canonical characteristics to the notation, for most use cases it is not appropriate to assume that two equivalent mixtures will have an identical MInChI description. The definition of a mixture is not a discrete concept as concentrations always have uncertainty associated with them (whether specified or not) and there are frequently unknown components (which may or may not be anticipated).

Detailed project information, specifications, presentations, links, etc. are available: https://github.com/IUPAC/MInChI

Gerd Blanke

Principal Consultant and Managing Director, StructurePendium Technologies GmbH

Alex M. Clark

Research Scientist, Collaborative Drug Discovery

Antony Davies

Professor of Analytical Science, U South Wales

Richard Hartshorn

Secretary General at International Union of Pure and Applied Chemistry

Chris Jakober

Air Pollution Specialist at CARB, Graduate Instructor at JHU

Leah Rae McEwen

Cornell University

Andrey Yerin

software development