Title: particle concentration
Long Title: IUPAC Gold Book - particle concentration
DOI: 10.1351/goldbook.P04423
Status: current

Definition
Commonly expressed in several ways: mass concentration (usually as \(\unicode[times]{x3BC}\rm{g}\ \rm{m}^{-3}\)) or number concentration (number of particles \(\pu{cm-3}\)); modern instrumentation allows measurement of the number of particles as a function of size as well as the total number present in a given air volume. For atmospheric aerosols, this is a complex distribution for which diameters range from below \(0.01\) to above \(100\ \unicode[Times]{x3BC}\rm{m}\); the particles making the highest contribution to the total number density are in the size range below \(0.1\ \unicode[times]{x3BC}\rm{m}\), those contributing most to the total surface area are in the \(0.1\) to \(1.0\ \unicode[times]{x3BC}\rm{m}\) range, while those with the highest contribution to the volume or mass of the aerosol come from both the \(0.1\) to \(1.0\ \unicode[times]{x3BC}\rm{m}\) and \(1.0\) to \(100\ \unicode[Times]{x3BC}\rm{m}\) ranges.

Related Terms
- aerosol: https://goldbook.iupac.org//terms/view/A00176
- number density: https://goldbook.iupac.org//terms/view/N04262

Source
- PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2181 (https://doi.org/10.1351/pac199062112167)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/P04423/html
- json: https://goldbook.iupac.org/terms/view/P04423/json
- xml: https://goldbook.iupac.org/terms/view/P04423/xml

Citation: Citation: 'particle concentration' 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.P04423
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Accessed: 2026-05-04T08:59:41+00:00