Title: chemical purity
Long Title: IUPAC Gold Book - chemical purity
DOI: 10.1351/goldbook.08014
Status: current

Definition
Mass (amount of substance or number of entities) of a specified component divided by the mass (amount of substance or number of entities, respectively) of the system.

Notes
1) Purity is usually related to a major component. The other components are termed "impurities".
2) The quantity, component, and system must be specified.
3) The numerical quantity value of purity is often expressed as per cent or per mille.
4) Purity can be estimated as \(1 - \sum_{j=1}^{j=N} f_{j}\), where \(f_{j}\) denotes fractions of the same type (mass fraction, amount of substance fraction or number fraction) of all other components \(j = 1, \dots, N\). If the contributions are expressed as mass fractions, this estimation is sometimes termed "mass balance".

Source
- PAC, 2021, 93, 997. 'Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)' on page 1003 (https://doi.org/10.1515/pac-2019-0819)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/08014/html
- json: https://goldbook.iupac.org/terms/view/08014/json
- xml: https://goldbook.iupac.org/terms/view/08014/xml

Citation: Citation: 'chemical purity' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.08014
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Accessed: 2026-06-28T03:11:58+00:00