Project Details Gold Book update of terms from the Glossary of Terms Related to Solubility

Project No.:
Start Date:
26 April 2021
End Date:


Because many terms related to solubility in the Orange Book and Gold Book (GB) were missing or inadequate, the Subcommittee on Solubility Data (SSED) undertook project 2005-017-1-500, “Glossary of terms related to solubility – updates and revisions to the Orange Book” (“the Glossary”) which resulted in a Recommendation containing 166 terms published in PAC in 2008 <>. In preparing this Recommendation the Task Group included, where it thought necessary revisions to terms then appearing in the GB (always noting such revisions in the Glossary text). As part of the current Union-wide effort to up-date the contents of the GB, the SSED now proposes to work with colleagues of other interested divisions to consider incorporation of these terms into the electronic version of the Gold Book.


This project will be part of a larger effort to up-date and revise the content of the GB, an activity which has been on hold for more than a decade while the format of the GB was modernize to allow future modifications and revisions to be made with greater ease. Because the Glossary includes not just specialized terms related nearly exclusively to solubility but also a significant number of terms used widely in equilibrium chemistry and beyond, it is important to work for consensus across IUPAC divisions. Discussions about this task have already begun among Divisions I, V and VI. Further outreach will be made to engage participation from other IUPAC bodies.

The Glossary of Terms related to Solubility, providing IUPAC definitions for 166 terms relevant to the study of solubility, was published in 2008. Since the Gold Book was last updated in 2006, many of these definitions may not be included in the Gold Book. The definitions under analysis were already presented as a recommendation, however further use of the glossary and the development of new fields of research showed that new terms should be considered and a systematic comparison with the new recommendations should be done. The revision of the Gold Book provides the opportunity for detailed reconsideration of these, and possibly other, terms relating to solubility.

The first step will be to make a table with the name of all the terms referred in the Glossary with their definitions.

In a second step the definitions will be compared with the existing text in Gold Book in the light of scientific developments. Depending on the situations definitions may be subject to revision or be accepted. Where revision is necessary a document will be written and will be circulated by the IUPAC Divisions in a future step.

Finally a list of new concepts and definitions to be included will be made.


Jan 2022 update – The main aims of the project are to compare the definitions presented in the “Glossary of terms related to solubility (IUPAC Recommendations 2008)” with those existing in the online version of the Gold Book as well as with possible changes that occurred during the updating of the “Orange Book”; and whenever necessary to update those definitions and if necessary to present new recommendations. This project is just beginning and a few terms were already analyzed.


Page last updated 13 Jan 2022